Tag: MONOGRAPH

  • DMAE

    Plain-language summaryIntrigue 38 / 100

    DMAE (2-(dimethylamino)ethanol) is a small molecule structurally related to choline that crosses the blood-brain barrier easily. The hypothesis has long been that it acts as a precursor to acetylcholine and phosphatidylcholine in the brain, but the evidence has been mixed and DMAE may actually be more of a methyl donor than a true cholinergic precursor. Its predecessor, deanol, was sold for ADHD until pulled from the US market in the 1980s for inadequate efficacy data. It survives in nootropic supplements and in topical skin-firming creams (the cosmetic mechanism is poorly understood). Reports of headaches and worsened depression in some users. Long-running compound with weak underlying evidence. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Tertiary aminoalcohol choline analog and putative acetylcholine precursor with antioxidant and membrane-active properties

    A naturally occurring dimethylated ethanolamine historically developed as the prescription drug Deaner for pediatric behavioral disorders, subsequently investigated for tardive dyskinesia, senile dementia, and dermatological aging, and now positioned as a dietary supplement cholinergic agent distinguished from conventional choline sources by competitive blood-brain barrier transport affinity and membrane phospholipid incorporation.

    Abstract

    Dimethylaminoethanol (DMAE), also known as deanol or 2-(dimethylamino)ethanol, is a tertiary aminoalcohol endogenous to human brain tissue and present at nutritionally relevant concentrations in certain marine fish species (sardines, anchovies, salmon). Structurally, DMAE differs from choline (2-hydroxyethyltrimethylammonium) by the absence of one N-methyl group, a distinction that confers higher lipophilicity, competitive affinity for the choline carrier at the blood-brain barrier (inhibition constant approximately 159 micromolar versus Michaelis constant approximately 442 micromolar for choline), and the capacity for incorporation into membrane phospholipids as phosphatidyldimethylaminoethanol (PDMAE) in place of phosphatidylcholine. The compound was developed by Riker Laboratories as deanol p-acetamidobenzoate (Deaner) and marketed from the 1960s through 1983 as a prescription medication for hyperkinetic syndrome (now termed attention-deficit/hyperactivity disorder) in children, on the basis of placebo-controlled trials demonstrating behavioral improvement comparable to methylphenidate at oral doses of 300 to 500 mg per day. The drug was voluntarily withdrawn in 1983 when the manufacturer elected not to submit the contemporary efficacy data required by evolving FDA regulatory standards, rather than for safety concerns. Subsequent clinical investigation extended to tardive dyskinesia, senile dementia, and dermatological applications. In tardive dyskinesia, a Cochrane systematic review and meta-analysis of randomized controlled trials concluded that DMAE was no more effective than placebo and was associated with an increased risk of adverse outcomes [1]. In senile dementia, open-label and small controlled trials produced modest behavioral improvements without measurable cognitive or memory enhancement [2]. The dermatological evidence base is more favorable: a randomized, double-blind, placebo-controlled trial of 3 percent DMAE facial gel applied daily for 16 weeks demonstrated statistically significant improvements in forehead lines, periorbital fine wrinkles, lip shape, and overall facial skin appearance, with effects maintained on cessation and safety confirmed through 12 months of open-label extension [3]. The pharmacological mechanism remains incompletely resolved. The classical hypothesis that DMAE serves as a direct acetylcholine precursor through sequential methylation to choline and subsequent acetylation by choline acetyltransferase has been challenged by disposition studies demonstrating that DMAE is not metabolized to choline in vivo and that its principal urinary metabolite is DMAE N-oxide [4]. Alternative mechanistic proposals include competitive inhibition of choline reuptake at the blood-brain barrier (thereby elevating peripheral choline concentrations), direct incorporation into neuronal membrane phospholipids as PDMAE with consequent alteration of membrane fluidity and receptor function, free radical scavenging activity against hydroxyl and lipid radicals confirmed by electron paramagnetic resonance spectroscopy [5], and anti-inflammatory activity through suppression of interleukin-2 and interleukin-6 secretion. DMAE is also the active moiety released by hydrolysis of centrophenoxine (meclofenoxate), a nootropic drug marketed in several jurisdictions for age-related cognitive decline, in which the para-chlorophenoxyacetic acid ester linkage enhances oral bioavailability and central nervous system penetration. The compound is currently available worldwide as a dietary supplement, typically formulated as the bitartrate salt at doses of 100 to 400 mg per day. The National Toxicology Program conducted prenatal developmental toxicity studies of DMAE bitartrate in Sprague Dawley rats (2020) and reported no maternal or fetal toxicity at gavage doses up to 1000 mg/kg/day, although in vitro exposure of neurulating mouse embryos to DMAE produced dose-dependent neural tube defects and craniofacial malformations at concentrations of 250 to 750 micromolar [6]. This monograph reviews the chemistry, structural relationships, and synthesis of DMAE; the contested cholinergic pharmacology in molecular and membrane-level detail; the comprehensive disposition and pharmacokinetic record; the preclinical evidence base spanning free radical scavenging, anti-inflammatory activity, and lipofuscin reduction; the clinical evidence across behavioral, neurological, cognitive, and dermatological indications; sourcing and quality verification considerations for research-grade material; reconstitution and handling protocols; stack interactions with choline donors, acetylcholinesterase inhibitors, and anticholinergic agents; adverse events and safety signals including the NTP developmental toxicity findings; and a structured comparative assessment of five cholinergic and nootropic alternatives against DMAE on five competency standards.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1447Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Flmodafinil

    Plain-language summaryIntrigue 48 / 100

    Flmodafinil is a fluorinated version of modafinil developed at the same Lafon laboratory in the 1980s. It reportedly binds the dopamine transporter more tightly than modafinil with longer duration. It never advanced to clinical development. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Bisfluorinated diphenylmethyl sulfinyl acetamide eugeroic and selective atypical dopamine reuptake inhibitor

    A bis(4-fluorophenyl) ring-substituted analog of modafinil developed at Laboratoire L. Lafon, distinguished from the parent compound by enhanced dopamine transporter affinity, prolonged wake-promoting duration, absence of cytochrome P450 enzyme induction, and a preclinical pharmacology profile suggesting superior potency-to-dose ratio with reduced sleep architecture disruption.

    Abstract

    Flmodafinil (CRL-40,940; NLS-4; lauflumide; bisfluoromodafinil; JBG01-41) is a synthetic eugeroic of the diphenylmethyl sulfinyl acetamide structural class, bearing two para-fluorine substituents on the phenyl rings of the modafinil scaffold. First synthesized and patented by Laboratoire L. Lafon in France in the mid-1980s as part of a systematic structure-activity exploration of modafinil derivatives, the compound remained largely uninvestigated for approximately two decades until NLS Pharmaceutics AG (formerly NLS Pharmaceuticals) acquired development rights and advanced it into preclinical programs for narcolepsy, attention deficit hyperactivity disorder, Alzheimer’s disease, idiopathic hypersomnia, and chronic fatigue syndrome. The compound acts as a selective atypical dopamine reuptake inhibitor with a binding affinity (Ki) of 4,090 nM at the dopamine transporter, approximately 12-fold selectivity over the serotonin transporter (Ki 48,700 nM), and negligible affinity for the sigma-1 receptor (Ki greater than 100,000 nM). In functional assays, flmodafinil blocks the dopamine transporter by approximately 83 percent, exceeding the inhibition produced by methylphenidate without concurrent adrenergic effects. Both the (S)-(+) enantiomer (JBG1-048, Ki 2,970 nM) and the (R)-(-) enantiomer (JBG1-049, Ki 4,830 nM) elevate extracellular dopamine in the rat nucleus accumbens to 150 to 200 percent of baseline at the highest assessed doses, with the (R)-(-) enantiomer producing a notably slower onset and longer duration of dopaminergic effect compared to (R)-modafinil. In the principal comparative preclinical study (Luca et al. 2018), NLS-4 at 64 mg/kg intraperitoneally in C57BL/6J mice induced approximately 151 minutes of additional wakefulness compared to approximately 110 minutes for modafinil at 150 mg/kg, a 2.3-fold higher dose, establishing that flmodafinil possesses substantially greater wake-promoting potency per milligram than the parent compound. Recovery sleep following NLS-4-induced wakefulness was characterized by less non-rapid eye movement (NREM) sleep amount and attenuated delta power elevation compared to modafinil-treated animals, suggesting a qualitatively different and possibly more favorable recovery profile with reduced homeostatic sleep pressure accumulation despite longer drug-induced wakefulness. A subsequent preclinical study in a rat model of chronic severe fatigue (Konofal et al. 2023) reported that NLS-4 at 16 mg/kg produced locomotor activity restoration comparable to modafinil at 64 mg/kg, confirming a four-fold potency advantage with more sustained effects on circadian activity patterns. Unlike modafinil, flmodafinil does not induce cytochrome P450 CYP3A4 or CYP3A5 enzymes in human hepatocyte cultures, a pharmacologically significant distinction that reduces the potential for drug-drug interactions in chronic dosing regimens. The compound has not been approved for medical use in any jurisdiction. Clinical development programs initiated by NLS Pharmaceutics for narcolepsy, ADHD, and Alzheimer’s disease have been discontinued without publication of human trial data; preclinical development for chronic fatigue syndrome remains the only active program as of the most recent public disclosure. No published human clinical trial data exist for flmodafinil. The World Anti-Doping Agency has initiated investigations into urinary metabolism and detection methods for flmodafinil and its structural relative fladrafinil (CRL-40,941), confirming regulatory awareness of the compound in the context of competitive sport. This monograph reviews the chemistry, synthesis, and stereochemistry of flmodafinil; the dopamine transporter pharmacology and enantiomer-resolved binding data; the preclinical wake-promoting and chronic fatigue evidence; the pharmacokinetic profile as characterized in animal models; sourcing and quality verification considerations for laboratory work; and a comparative assessment of five eugeroic and wakefulness-promoting alternatives against flmodafinil on five competency standards. The compound is supplied exclusively as a research-grade preparation; investigators should obtain analytical confirmation of identity, purity, and enantiomeric composition on every lot.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1438Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Unifiram

    Plain-language summaryIntrigue 38 / 100

    Unifiram is closely related to sunifiram with similar AMPA receptor modulation. Both are research compounds with limited clinical evaluation. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Piperazine-derived ampakine-like nootropic with AMPA receptor-mediated cognition-enhancing activity

    A hexahydropyrrolo[1,2-a]pyrazinone cognition enhancer synthesized at the University of Florence, approximately 1000-fold more potent than piracetam in rodent antiamnesic assays, operating through AMPA receptor-dependent glutamatergic facilitation and cholinergic release enhancement without direct binding to any characterized central receptor.

    Abstract

    Unifiram (DM-232) is an experimental nootropic compound of the hexahydropyrrolo[1,2-a]pyrazinone structural class, synthesized in the late 1990s at the University of Florence by the research group led by Fulvio Gualtieri within the Department of Pharmaceutical Sciences. The compound was first disclosed in 2000 and characterized in a series of publications by Ghelardini, Galeotti, Romanelli, and colleagues between 2002 and 2006. Unifiram is approximately 1000-fold more potent than piracetam in the mouse passive avoidance test and the rat Morris water maze, the standard behavioral assays for antiamnesic and procognitive activity in the racetam research tradition. The compound prevents amnesia induced by scopolamine (muscarinic antagonism), mecamylamine (nicotinic antagonism), baclofen (GABA-B agonism), and clonidine (alpha-2 adrenergic agonism) at intraperitoneal doses of 0.001 to 0.1 mg/kg and oral doses of 0.01 to 0.1 mg/kg in mice, with no impairment of motor coordination on the rota rod test at doses up to 10 mg/kg.

    The mechanism of action is not fully elucidated, but the available evidence supports AMPA receptor-dependent glutamatergic facilitation as the principal pharmacological activity. Unifiram reverses amnesia induced by the selective AMPA receptor antagonist NBQX, increases the amplitude of field excitatory postsynaptic potentials (fEPSP) in rat hippocampal slices in a concentration-dependent manner, and stimulates acetylcholine release from rat cerebral cortex in vitro. Despite these functional effects, unifiram shows no measurable affinity for any of the principal central nervous system receptors, ion channels, or transporters at concentrations up to 1 micromolar in standard radioligand binding panels, including glutamate (AMPA, NMDA, kainate), GABA, serotonin, dopamine, adrenergic, histamine, muscarinic, nicotinic, and opioid sites. The compound therefore appears to operate through an indirect or allosteric mechanism on AMPA receptor-mediated neurotransmission rather than through direct orthosteric binding.

    Sunifiram (DM-235), the molecular simplification of unifiram produced by the same research group, retains comparable potency and shares the AMPA-dependent mechanism. A third analog, sapunifiram (MN-19), has also been characterized with similar activity. The structure-activity relationship program at Florence explored modifications of the piperazine and bicyclic ring systems and identified compounds with amnesing (pro-amnestic) activity of comparable potency to scopolamine, confirming the pharmacological specificity of the cognition-enhancing scaffold.

    No human clinical trials of unifiram have been conducted. No formal toxicology studies beyond acute rodent dosing have been published. The compound was never patented, and by approximately 2012 it appeared on commercial websites as a consumer nootropic despite the absence of human safety or efficacy data. The 2015 commentary by Gualtieri in the Journal of Enzyme Inhibition and Medicinal Chemistry characterized the commercial availability of unifiram and sunifiram as an illustration of academic and industrial shortcomings in the translation of early-stage research compounds. The compound is not approved for human use in any jurisdiction. It is not scheduled as a controlled substance in most jurisdictions but is sold as a research chemical. Investigators should obtain analytical confirmation of identity and purity on every lot and should not extrapolate rodent dose-response data to human applications without appropriate pharmacokinetic and safety characterization.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1434Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Centrophenoxine

    Plain-language summaryIntrigue 52 / 100

    Centrophenoxine (meclofenoxate) is a 1959-vintage cognitive enhancer that pairs DMAE, a choline-related compound, with a small chlorinated acid. After it crosses into the brain, it splits and does two things: it feeds the acetylcholine system and it helps clear lipofuscin, the brownish junk pigment that accumulates inside aged brain and skin cells. The lipofuscin clearance angle is the unusual part; few compounds do it. It has been sold as a memory drug in Europe and Latin America since the 1960s for senile cognitive impairment, but the modern clinical evidence is thin and mostly old. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Cholinergic precursor ester combining dimethylaminoethanol and 4-chlorophenoxyacetic acid with lipofuscin-clearing and neuroprotective activity

    A synthetic ester of dimethylaminoethanol and para-chlorophenoxyacetic acid developed in 1959 at the French National Scientific Research Center, distinguished from other cholinergic precursors by its capacity to reduce neuronal lipofuscin accumulation and to enhance phospholipid membrane turnover in aging brain tissue.

    Abstract

    Centrophenoxine (meclofenoxate, Lucidril; 2-(dimethylamino)ethyl (4-chlorophenoxy)acetate; CAS 51-68-3; molecular formula C12H16ClNO3; molecular weight 257.71 g/mol) is a synthetic cholinergic precursor and neuroprotective agent developed in 1959 at the Centre National de la Recherche Scientifique (CNRS) in France. The compound is an ester of two biologically active moieties: dimethylaminoethanol (DMAE), a naturally occurring aminoalcohol found in small quantities in the human brain and implicated in choline and phospholipid metabolism, and para-chlorophenoxyacetic acid (pCPA), a synthetic auxin derivative that serves as a lipophilic carrier facilitating blood-brain barrier penetration and extending the biological half-life of the DMAE component. Following oral administration, centrophenoxine undergoes rapid hepatic ester hydrolysis to release DMAE and pCPA. The DMAE moiety is subsequently methylated to choline, which enters the acetylcholine synthetic pathway and is incorporated into membrane phospholipids as phosphatidyldimethylaminoethanol and phosphatidylcholine. The compound’s most distinctive pharmacological feature is the reduction of lipofuscin, the heterogeneous age pigment that accumulates progressively in postmitotic cells including cortical and hippocampal neurons, cardiac myocytes, and retinal pigment epithelium. The lipofuscin-clearing activity was first demonstrated by Nandy and Bourne in 1966 in senile guinea pig neurons and has been replicated across multiple rodent species, with reductions of 25 to 40 percent in cortical and hippocampal lipofuscin content following chronic oral administration at doses of 40 to 80 mg/kg/day for three to six months [1, 2]. The mechanism of lipofuscin clearance is incompletely characterized but is attributed to a combination of enhanced lysosomal enzyme activity, increased membrane phospholipid turnover (which dilutes the lipofuscin granule burden through membrane remodeling), and direct free radical scavenging by the DMAE moiety, which is incorporated into neuronal membranes as phosphatidyl-DMAE and functions as a hydroxyl radical scavenger [3, 4]. The clinical evidence base in human cognitive impairment spans approximately five decades but is modest in scale and quality by contemporary standards. The largest double-blind, randomized, placebo-controlled trial in healthy elderly subjects (Marcer and Hopkins, 1977; n = 50) demonstrated significant improvement in delayed free recall after three months of oral centrophenoxine at 600 mg twice daily, with no effect on immediate recall, digit span, or recognition memory, suggesting a selective enhancement of memory consolidation into long-term storage [5]. A second double-blind trial in 50 patients with organic dementia (Pek and Fulop, 1983) reported improvement in 48 percent of centrophenoxine-treated subjects versus 28 percent on placebo, although with high variability and methodological limitations [6]. Smaller open-label and controlled studies have reported improvements in vigilance, reaction time, and subjective mental alertness in elderly populations. The compound is marketed as a prescription medicine in several European countries (France, Germany, Hungary, Austria), in Japan, and in parts of Latin America for indications including senile cognitive impairment, post-stroke cognitive rehabilitation, and alcohol-related cognitive decline. It is not approved by the United States Food and Drug Administration and is sold as a research chemical in the United States. Pharmacokinetics are characterized by rapid oral absorption, rapid hepatic ester hydrolysis (plasma half-life of the parent ester is approximately 30 to 60 minutes), and a longer effective duration attributable to the persistence of the DMAE metabolite in brain tissue. Typical clinical doses range from 600 to 2000 mg per day in two or three divided administrations. The adverse-event profile is favorable; the most commonly reported effects are mild gastrointestinal discomfort, insomnia, and headache, generally at higher doses and resolving with dose reduction. This monograph reviews the chemistry, synthesis, and structural pharmacology of centrophenoxine; the lipofuscin-clearing, cholinergic, antioxidant, and membrane-modifying mechanisms; the pharmacokinetic profile; the preclinical and clinical evidence base; sourcing and quality verification; reconstitution and handling; stack interactions with racetams and other cholinergic agents; the adverse-event and safety profile; and a comparative assessment of five cholinergic and neuroprotective alternatives (alpha-GPC, citicoline, DMAE, piracetam, and idebenone) against centrophenoxine on five competency standards.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1445Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Fladrafinil

    Plain-language summaryIntrigue 38 / 100

    Fladrafinil is the fluorinated cousin of adrafinil from the same Lafon series. It is a prodrug that the liver converts to flmodafinil. Sparse pharmacology data suggest similar profile to flmodafinil with slightly shorter onset. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Fluorinated diphenylmethylsulfinyl hydroxamic acid eugeroic and prodrug of flmodafinil

    A bis(4-fluorophenyl)-substituted analog of adrafinil developed at Laboratoire L. Lafon as a wakefulness-promoting agent with reported anti-aggressive properties in animal models, functioning as a prodrug of the dopamine transporter inhibitor flmodafinil and distinguished from its parent compound by fluorine substitution at both para-phenyl positions.

    Abstract

    Fladrafinil (CRL-40,941), also designated fluorafinil and bisfluoroadrafinil, is a synthetic diphenylmethylsulfinyl hydroxamic acid eugeroic compound first synthesized at Laboratoire L. Lafon in Paris in the late 1970s to early 1980s as part of the benzhydryl sulfinyl series that also produced adrafinil (CRL-40,028) and modafinil (CRL-40,476). The compound is the bis(4-fluoro) ring-substituted derivative of adrafinil and functions as a prodrug that undergoes hepatic amide hydrolysis to yield flmodafinil (CRL-40,940, bisfluoromodafinil), a selective atypical dopamine reuptake inhibitor with a reported dopamine transporter (DAT) Ki of approximately 4,090 nM and 83 percent DAT blockade in vitro [1, 2]. Fladrafinil was disclosed in a 1984 United States patent (US 4,489,095) assigned to Lafon, in which preclinical animal data demonstrated wakefulness promotion and, distinctively, anti-aggressive behavioral effects in rodent aggression paradigms at intraperitoneal doses of 16 to 1,024 mg/kg, a property not shared by the parent compound adrafinil [3]. The anti-aggressive activity, reported at potencies three to four times greater than adrafinil on a weight basis, represented the principal pharmacological distinction identified during the original Lafon screening campaign and suggested a differentiated central nervous system profile relative to the non-fluorinated congeners. Despite these early findings, fladrafinil was never advanced to formal clinical development. No peer-reviewed human pharmacokinetic, efficacy, or safety studies have been published. The compound was not registered in any jurisdiction and was not assigned an International Nonproprietary Name. The pharmacological characterization of fladrafinil therefore rests entirely on the Lafon patent disclosures, on inference from the well-characterized pharmacology of its active metabolite flmodafinil and of the closely related modafinil and adrafinil, and on recent analytical chemistry investigations conducted under the auspices of the World Anti-Doping Agency (WADA) to establish urinary and blood detection markers for anti-doping surveillance [4, 5]. Flmodafinil itself has been characterized as a selective DAT inhibitor that blocks the dopamine transporter at 83 percent occupancy without inducing cytochrome P450 3A4 or 3A5, that maintains wakefulness over a longer timeframe than modafinil in animal models with reduced perturbation of sleep architecture, and that elevates nucleus accumbens dopamine concentrations by approximately 150 to 200 percent at peak doses [1, 2]. The active metabolite has been in preclinical development for chronic fatigue syndrome, though clinical programs for narcolepsy, attention deficit hyperactivity disorder, and Alzheimer’s disease have been discontinued as of early 2024. Fladrafinil entered public awareness principally through the nootropic and dietary supplement markets beginning approximately 2015, where it is sold as a research-grade powder or capsule preparation at purities typically stated as 98 percent or greater. The compound is classified under the WADA Prohibited List as a class S6 non-specified stimulant (prohibited in-competition) and has been the subject of analytical investigations by Krug, Thevis, and colleagues at the German Sport University Cologne into its metabolism, elimination kinetics, and detection windows in urine and dried blood spots [4, 5]. This monograph reviews the chemistry, structural relationships, known and inferred pharmacology, pharmacokinetics, the absence of clinical evidence, sourcing and quality considerations, reconstitution and handling, stack interactions, adverse-event signal, and a comparative assessment of five eugeroic and wakefulness-promoting compounds against fladrafinil on five competency standards.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1439Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • IDRA-21

    Plain-language summaryIntrigue 50 / 100

    IDRA-21 is a benzothiadiazide ampakine developed at the University of Milan. It enhances AMPA receptor function and showed cognitive enhancement in primate studies. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Benzothiadiazine-class positive allosteric modulator of AMPA-type glutamate receptors (ampakine)

    A benzothiadiazine derivative developed at the Nathan S. Kline Institute as a partial negative allosteric modulator of AMPA receptor desensitization, distinguished from cyclothiazide and the racetam-class ampakines by partial intrinsic activity, prolonged duration of cognitive enhancement, absence of neurotoxicity at pharmacologically active doses, and oral bioavailability with central nervous system penetration in rodent and primate species.

    Abstract

    IDRA-21 (7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine S,S-dioxide; CAS 22503-72-6; molecular formula C8H9ClN2O2S; molecular weight 232.69 g/mol) is a benzothiadiazine derivative that acts as a positive allosteric modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) type glutamate receptors by attenuating receptor desensitization. The compound was synthesized and characterized at the Nathan S. Kline Institute for Psychiatric Research in Orangeburg, New York, under the direction of Erminio Costa and Alessandro Guidotti in the early 1990s, and was advanced through preclinical development by Fidia Farmaceutici SpA of Abano Terme, Italy, before discontinuation in October 2003 without entry into human clinical trials.

    The mechanism of action is partial negative allosteric modulation of AMPA receptor desensitization, a pharmacological property that distinguishes IDRA-21 from the full modulators cyclothiazide and diazoxide. In cultured cerebellar granule neurons, IDRA-21 increases the sodium transient with a threshold concentration approximately 10-fold higher than cyclothiazide and an intrinsic activity significantly lower than that of cyclothiazide, producing a shorter-lasting calcium transient and, critically, complete absence of neurotoxicity at concentrations up to 100 micromolar in the presence of AMPA, compared to the severe neurotoxicity produced by cyclothiazide at 5 to 25 micromolar under identical conditions. The partial modulator mechanism therefore provides a wide therapeutic index between the concentrations that enhance cognition and those that produce excitotoxic neuronal injury.

    The compound is a chiral molecule possessing one stereocenter at the 3-position of the benzothiadiazine ring. Enantiomeric resolution by Uzunov et al. (1995) using a custom chiral stationary phase demonstrated that the dextrorotatory (+)-IDRA-21 enantiomer is the pharmacologically active form in rat water maze performance, whereas the levorotatory (-)-enantiomer is devoid of activity at comparable doses. The racemate has been used in all published in vivo behavioral studies.

    Preclinical cognitive enhancement has been documented across multiple species, behavioral paradigms, and impairment models. In rat passive avoidance and water maze tasks, racemic IDRA-21 at oral doses of 1 to 3 micromol/kg reverses cognitive deficits induced by alprazolam (a GABAergic positive modulator) and scopolamine (a muscarinic antagonist), with effect persisting for 3 to 4 hours after a single oral dose. In patas monkeys working in a complex operant learning task, IDRA-21 at 3 to 5.6 mg/kg orally antagonized alprazolam-induced learning deficits and was estimated to be approximately 10-fold more potent than aniracetam in this paradigm. In young adult and aged rhesus monkeys performing a delayed matching-to-sample task, oral IDRA-21 at 0.15 to 10 mg/kg produced robust improvements in task accuracy, with effects sustained to 48 hours after a single dose and accuracy on long-delay (most difficult) trials increased by up to 34 percent of vehicle at the individualized best dose. In young macaques performing a visual recognition memory task, oral IDRA-21 significantly improved performance on the longest delay condition.

    A secondary pharmacological activity has been characterized: IDRA-21 negatively modulates NMDA receptor function in cultured cerebellar granule cells, with partial selectivity for NR2B-containing receptor assemblies. The NMDA receptor inhibition is neither competitive nor voltage-dependent and may contribute to the neuroprotective and cognitive profiles by tempering excessive NMDA receptor activation while potentiating AMPA receptor currents.

    The principal safety concern identified in preclinical studies is the enhancement of ischemic neuronal injury. Yamada et al. (1998) demonstrated that IDRA-21 at 12 and 24 mg/kg orally increases CA1 hippocampal neuron loss following 10 minutes of global ischemia in rats, and that glutamate plus IDRA-21 produces AMPA receptor-dependent neurotoxicity in cultured hippocampal neurons. This finding has implications for any future clinical development in populations at risk of cerebrovascular events.

    No human clinical trials have been conducted with IDRA-21. The compound was discontinued from development by Fidia Farmaceutici in October 2003. It remains available from multiple research-grade chemical suppliers at greater than 98 percent purity and is used as a reference compound in AMPA receptor pharmacology research and as a tool compound for the study of glutamatergic contributions to cognition and synaptic plasticity.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1436Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Procaine

    Plain-language summaryIntrigue 42 / 100

    Procaine is the original synthetic local anesthetic, synthesized in 1905 by Alfred Einhorn and marketed by Hoechst as Novocain. It was developed as a non-addictive cocaine substitute and dominated the field from 1905 through the 1950s before lidocaine and the amide class displaced it owing to faster onset, longer duration, and far fewer allergic reactions. The ester-class downside: hydrolysis by plasma cholinesterase produces para-aminobenzoic acid (PABA), the dominant allergen in the class. Plasma half-life of procaine itself is under one minute; clinical infiltration block lasts only 30 to 60 minutes. Modern use is essentially restricted to short-procedure infiltration in patients with documented amide allergy and to a few dental applications. Procaine penicillin (the depot antibiotic formulation) is the oldest application of procaine in pharmaceutical formulation and is the principal reason most clinicians have heard of it. Not stocked by Kodiac. This monograph is provided for research and educational reference.

    Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

    Ester local anesthetic (short-acting)

    The original synthetic local anesthetic introduced in 1905 as Novocaine, displaced by amide agents but retaining historical and reference status.

    Abstract

    Procaine (2-(diethylamino)ethyl 4-aminobenzoate; CAS 59-46-1; molecular formula C13H20N2O2; molecular weight 236.31) is the original synthetic local anesthetic, synthesized by Alfred Einhorn at the University of Munich in 1905 and marketed by Hoechst as Novocain. The compound was developed as a cocaine substitute that lacked the abuse liability and addictive potential of the natural alkaloid; the ester linkage between the aromatic ring and the amino alcohol substantially reduces lipophilicity relative to cocaine while preserving sodium channel block. Procaine was the dominant local anesthetic from 1905 through approximately the 1950s, when lidocaine and the amide class displaced it owing to faster onset, longer duration, and substantially lower allergic reaction incidence. The principal limitation of procaine and the ester class is hydrolysis by plasma cholinesterase to para-aminobenzoic acid (PABA), the dominant allergen in the class and a substrate for hapten-mediated immune reactions in sensitized individuals. The plasma half-life is short (less than 1 minute through cholinesterase clearance); duration of clinical infiltration block is 30 to 60 minutes, much shorter than amide agents. Mechanism is voltage-gated sodium channel block with state-dependent kinetics; the lower lipid solubility relative to amide agents corresponds to slower onset and weaker block per milligram. Maximum recommended dose is 7 mg/kg, with adjustment for patients with cholinesterase deficiency (prolonged duration, increased systemic exposure). Modern clinical use is limited to short-procedure infiltration in patients with documented amide allergy and to several dental applications in markets where the ester formulations remain available. Procaine penicillin (combined with penicillin G as a depot) extends antibiotic plasma levels and is the oldest application of procaine in formulation.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1314Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • GDF-11

    TGF-beta superfamily growth differentiation factor

    A growth differentiation factor in the TGF-beta superfamily originally implicated in parabiosis-mediated rejuvenation and subsequently a focus of contested replication studies in cardiac and skeletal muscle aging.

    Abstract

    GDF-11 (growth differentiation factor 11; bone morphogenetic protein 11, BMP-11; CAS 268544-12-9; mature peptide molecular weight approximately 12.5 kDa as a homodimer) is a member of the transforming growth factor beta (TGF-beta) superfamily, closely related to myostatin (GDF-8) with which it shares approximately 90 percent amino acid identity in the mature C-terminal domain. The compound came to prominence in 2013 when a heterochronic parabiosis study by Amy Wagers and Richard Lee at the Harvard Stem Cell Institute identified GDF-11 as a putative young-blood-borne rejuvenation factor that reversed age-related cardiac hypertrophy when administered to old mice. Subsequent studies extended the proposed rejuvenation activity to skeletal muscle and the central nervous system. The original GDF-11 papers triggered substantial follow-up research and substantial contested replication: independent groups (notably the Glass laboratory at Eli Lilly and the Wagers laboratory’s own subsequent work) reported that the original immunoassays did not adequately distinguish GDF-11 from myostatin, that circulating GDF-11 levels do not in fact decline with age, and that recombinant GDF-11 administered to old mice produces muscle wasting at high doses (consistent with the myostatin-like activity expected from the structural homology) rather than rejuvenation. The contested literature has not produced consensus; some groups continue to report modest pro-cardiac and pro-cognitive effects of GDF-11 at carefully titrated doses, while others find no effect or harmful effects. Mechanism is canonical TGF-beta superfamily signaling through ActRIIA/B receptors and downstream SMAD2/3 transcription factor activation; GDF-11 and myostatin share the same receptor and signaling pathway, distinguishing them principally through tissue-specific expression patterns and post-translational propeptide regulation. The compound is research-grade with no regulatory approval and no active clinical development. Investigators studying GDF-11 should be aware of the contested replication literature and the importance of distinguishing GDF-11 from myostatin in immunoassays.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1346Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Apraglutide

    Long-acting glucagon-like peptide-2 receptor agonist

    A rationally designed, DPP-IV-resistant, long-acting synthetic analog of human glucagon-like peptide-2 bearing four amino acid substitutions that confer very low systemic clearance and high plasma protein binding, enabling once-weekly subcutaneous dosing for the treatment of short bowel syndrome with intestinal failure and under investigation for steroid-refractory gastrointestinal acute graft-versus-host disease.

    Abstract

    Apraglutide (FE 203799) is a synthetic 33-amino-acid peptide analog of human glucagon-like peptide-2 (GLP-2) and a potent, selective, full agonist of the GLP-2 receptor (GLP-2R), developed as a next-generation intestinotrophic agent for the treatment of short bowel syndrome with intestinal failure (SBS-IF) and under investigation for steroid-refractory gastrointestinal acute graft-versus-host disease (GI aGVHD). The compound differs from native human GLP-2(1-33) by four amino acid substitutions ([Gly2, Nle10, D-Phe11, Leu16]hGLP-2(1-33)-NH2) that confer resistance to dipeptidyl peptidase-IV (DPP-IV) degradation, very low systemic clearance, slow absorption from the subcutaneous depot, and high plasma protein binding, resulting in an elimination half-life of approximately 72 hours in healthy volunteers and enabling once-weekly subcutaneous administration [1, 2]. In head-to-head rat intravenous pharmacokinetic comparisons, apraglutide demonstrated a clearance of 0.27 mL/kg per minute versus 9.9 mL/kg per minute for teduglutide and 2.8 mL/kg per minute for glepaglutide, and an elimination half-life of 159 minutes versus 19 minutes for teduglutide and 16 minutes for glepaglutide [1]. The compound retains potency and selectivity at the human GLP-2 receptor comparable to native GLP-2 and teduglutide, with approximately two-fold greater potency than both in cell-based receptor activation assays [1]. Apraglutide was originally discovered at Ferring Pharmaceuticals (development code FE 203799) and subsequently licensed to GLyPharma Therapeutic in 2012, acquired by Therachon (a Novo Holdings-backed rare disease company), transitioned to VectivBio AG, and acquired by Ironwood Pharmaceuticals in 2023 [3, 4]. The compound received orphan drug designation from the United States Food and Drug Administration, the European Medicines Agency, and the Japanese regulatory authority for SBS-IF. The pivotal Phase 3 STARS trial (NCT04627025), a global, randomized, double-blind, placebo-controlled study in 164 adults with SBS-IF across 73 centers in 18 countries, met its primary endpoint: apraglutide-treated patients achieved a 25.5 percent relative reduction in weekly parenteral support volume at week 24 versus 12.5 percent for placebo (P = 0.001), with treatment effect evident from week 8 [5, 6]. Secondary endpoints demonstrated that 43 percent of apraglutide-treated patients gained at least one additional day off parenteral support per week (versus 27.5 percent for placebo, P = 0.04), and 6.4 percent of apraglutide-treated patients achieved complete enteral autonomy at week 24 compared to 0 percent on placebo [5]. Long-term extension data through 48 weeks showed 12.5 percent of apraglutide-treated patients achieving enteral autonomy versus 7.4 percent on placebo, with 27 patients overall achieving enteral autonomy across the development program [7]. In metabolic balance studies, once-weekly apraglutide at 5 mg subcutaneous increased wet weight absorption by 741 g/day, increased energy absorption by 1095 kJ/day, and increased sodium absorption by 38 mmol/day, making apraglutide the first GLP-2 analog to significantly improve energy absorption across the full SBS patient spectrum as measured by bomb calorimetry [8, 9]. The Phase 2 STARGAZE trial in steroid-refractory GI aGVHD demonstrated a 58.1 percent overall response rate at day 28 (versus 38.8 percent in a matched MAGIC control cohort) and a lower cumulative non-relapse mortality at day 180 (33.3 percent versus 41.9 percent) [10]. Adverse events across the clinical program have been predominantly mild to moderate gastrointestinal effects (decreased stoma output, stoma complications, nausea, flatulence, abdominal pain) consistent with the pharmacological intestinotrophic mechanism, with injection site reactions, polyuria, and edema also reported at low incidence [8, 11]. Ironwood Pharmaceuticals initiated a rolling NDA submission in January 2025; following FDA feedback requiring a confirmatory Phase 3 trial, the STARS-2 study is planned with site initiations in the second quarter of 2026 and an NDA submission target before end of 2029 [7, 12]. This monograph reviews the chemistry and peptide engineering of apraglutide; the GLP-2 receptor pharmacology and downstream intestinotrophic signaling; the comprehensive pharmacokinetic profile in healthy volunteers, SBS patients, and special populations; the preclinical intestinal growth pharmacology; the clinical evidence base across SBS-IF, metabolic balance, and GI aGVHD indications; sourcing and quality verification; reconstitution and handling; stack interactions; adverse events and safety signal; and a comparative assessment of five GLP-2 receptor agonist candidates against apraglutide on five competency standards. The compound is not approved by any regulatory authority as of the monograph revision date.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1416Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

  • Glepaglutide

    Long-acting glucagon-like peptide-2 (GLP-2) receptor agonist peptide analog

    A 39-amino-acid synthetic peptide analog of human glucagon-like peptide-2 engineered by Zealand Pharma with nine amino acid substitutions and a C-terminal hexalysine tail to enable depot formation, extended half-life, and ready-to-use liquid formulation for subcutaneous administration in short bowel syndrome.

    Abstract

    Glepaglutide (ZP1848) is a long-acting, synthetic peptide analog of human glucagon-like peptide-2 (GLP-2) developed by Zealand Pharma A/S (Soeborg, Denmark) for the treatment of short bowel syndrome (SBS) with intestinal failure in patients dependent on parenteral support. The compound comprises 39 amino acids and differs from native human GLP-2(1-33) by the incorporation of nine amino acid substitutions at positions 2, 3, 5, 8, 10, 11, 16, 24, and 28, together with a C-terminal amidated hexalysine tail ([Lys]6-NH2) derived from Zealand Pharma’s proprietary Structure Inducing Probe (SIP) technology. The substitutions confer resistance to dipeptidyl peptidase-4 (DPP-4) degradation, improved physicochemical stability enabling a ready-to-use aqueous liquid formulation, and formation of a subcutaneous depot from which the parent compound and its active C-terminally truncated metabolites (M1, 35 amino acids; M2, 34 amino acids) are slowly released into systemic circulation. The resulting effective half-life of approximately 50 to 124 hours in humans permits twice-weekly or once-weekly subcutaneous dosing, a substantial advance over the daily injection requirement of teduglutide (Gattex), the first-in-class approved GLP-2 analog. Glepaglutide binds and activates the GLP-2 receptor (GLP-2R), a class B G-protein-coupled receptor expressed on intestinal subepithelial myofibroblasts, enteroendocrine cells, and enteric neurons. Receptor activation triggers downstream release of intestinal growth mediators including insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), and keratinocyte growth factor, resulting in crypt cell proliferation, villus elongation, inhibition of enterocyte apoptosis, enhanced intestinal barrier function, increased mesenteric blood flow, and suppression of gastric acid hypersecretion and accelerated gastrointestinal motility. The net physiological effect is increased intestinal absorptive capacity for fluid, electrolytes, and macronutrients in patients with anatomically shortened bowel. Clinical development has progressed through Phase 1 healthy volunteer pharmacokinetic studies, a Phase 2 randomized crossover trial in 18 SBS patients published in The Lancet Gastroenterology and Hepatology (Naimi et al., 2019) demonstrating dose-dependent improvements in intestinal wet weight absorption and plasma citrulline, and the pivotal Phase 3 EASE-SBS 1 trial (NCT03690206), a multinational, double-blind, placebo-controlled study in 106 patients that met its primary endpoint of significant reduction in weekly parenteral support volume at 24 weeks (mean change minus 5.13 versus minus 2.85 liters per week for glepaglutide twice weekly versus placebo; P equals 0.0039). The compound received orphan drug designation from both the United States Food and Drug Administration and the European Medicines Agency. Zealand Pharma submitted a New Drug Application to the FDA in late 2023; in December 2024, the FDA issued a Complete Response Letter citing insufficient evidence to confirm efficacy and safety at the proposed marketed dose and recommending an additional confirmatory trial. A Marketing Authorization Application was submitted to the European Medicines Agency in June 2025, and Zealand Pharma plans an additional Phase 3 trial to support regulatory resubmission in the United States. The safety profile is consistent with the known GLP-2 class effects. The most frequent adverse events in clinical trials are injection site reactions, stoma complications (primarily swelling or enlargement of the stoma nipple), gastrointestinal events (nausea, vomiting, abdominal pain), peripheral edema, fatigue, and headache. Anti-drug antibodies develop in a proportion of treated patients with a trend toward higher injection site reaction incidence in antibody-positive individuals, though no firm causal relationship has been established. The compound does not require reconstitution and is administered as a fixed-dose, ready-to-use subcutaneous injection via autoinjector, representing a practical advantage over lyophilized GLP-2 analogs requiring daily preparation. This monograph documents the chemistry, design rationale, and synthesis of glepaglutide; the GLP-2 receptor pharmacology and downstream intestinotrophic signaling; the comprehensive human pharmacokinetic profile including depot formation and metabolite characterization; the preclinical pharmacology in intestinal growth and inflammatory bowel disease models; the clinical evidence base from Phase 1 through Phase 3; sourcing and quality verification; reconstitution and handling; stack interaction considerations; adverse events and safety signals; and a comparative assessment of five GLP-2 receptor agonist candidates (teduglutide, apraglutide, dapiglutide, elsiglutide, and native GLP-2) against glepaglutide on five competency standards.

    Read the full monograph

    The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

    KDC-MN-1414Open in new tab →

    Download PDF →

    FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.