Tag: MONOGRAPH

  • Primobolan

    Synthetic androstane anabolic-androgenic steroid; 1-methyl dihydrotestosterone derivative with moderate androgen receptor agonism

    A non-17-alpha-alkylated dihydrotestosterone derivative developed by Squibb and Schering for refractory anemia and catabolic wasting, distinguished from other anabolic-androgenic steroids by its favorable hepatic safety profile, absence of aromatization, and moderate anabolic-to-androgenic dissociation.

    Abstract

    Primobolan is the trade name for metenolone (also rendered methenolone), a synthetic androstane steroid derived from dihydrotestosterone (DHT) by introduction of a 1-methyl group and a 1,2-double bond into the A-ring of the 5-alpha-reduced androstane nucleus. The compound was first synthesized in 1960 and introduced for clinical use in 1961 by Squibb Pharmaceuticals in the United States (as Nibal and Nibal Depot) and by Schering AG in West Germany (as Primobolan and Primobolan Depot). Two ester prodrug forms are manufactured: metenolone acetate (CAS 434-05-9), the oral preparation with a molecular weight of 344.50 g/mol, and metenolone enanthate (CAS 303-42-4), the intramuscular depot preparation with a molecular weight of 414.63 g/mol. Both esters undergo hydrolysis in vivo to release the parent steroid metenolone (CAS 153-00-4; molecular formula C20H30O2; molecular weight 302.46 g/mol), which binds the androgen receptor with moderate affinity and produces anabolic effects in skeletal muscle, bone, and erythropoietic tissue.

    The clinical pharmacology of metenolone is defined by several characteristics that distinguish it from structurally related anabolic-androgenic steroids. First, the compound is not 17-alpha-alkylated; the 1-methyl substitution and ester conjugation confer sufficient oral bioavailability (in the acetate form) and depot duration (in the enanthate form) without the hepatotoxic liability associated with C17-alpha-alkylated steroids such as oxymetholone, stanozolol, and methandrostenolone. Second, the 1,2-double bond and the DHT-derived backbone render metenolone resistant to aromatization by the cytochrome P450 aromatase enzyme complex (CYP19A1), eliminating estrogenic side effects including gynecomastia and estrogen-mediated fluid retention. Third, metenolone exhibits a moderate anabolic-to-androgenic dissociation ratio of approximately 88:44 to 150:50 in rodent bioassays (levator ani weight gain versus ventral prostate weight gain, relative to testosterone propionate as the reference standard), placing it in the class of mildly anabolic, mildly androgenic agents alongside oxandrolone and drostanolone.

    The principal approved clinical indication was the treatment of anemia due to bone marrow failure, including aplastic anemia, myelofibrosis, and refractory cytopenias. A therapeutic trial reported by Compagno et al. (1978) in 19 consecutive patients with refractory anemia demonstrated remission in approximately 37 percent of patients with pancytopenia and variable responses across other cytopenia subtypes [1]. Additional historical indications included protein-calorie malnutrition, postoperative and post-infectious catabolic states, osteoporosis, sarcopenia, and promotion of weight gain in premature infants. The compound has been largely discontinued from clinical markets; as of the most recent monograph revision, metenolone enanthate is marketed only in Spain and Turkey (as Primobolan Depot), and metenolone acetate retains limited availability in Japan and Moldova.

    Pharmacokinetics differ substantially between the two ester forms. Metenolone acetate is rapidly absorbed after oral administration but undergoes significant first-pass hepatic metabolism, resulting in reduced oral bioavailability relative to parenteral administration; the plasma half-life of the oral form is approximately 4 to 6 hours. Metenolone enanthate, administered by intramuscular injection in an oil vehicle, provides depot release with a biological half-life of approximately 10.5 days and a duration of action of approximately 14 days. Metabolism of metenolone proceeds through hepatic mixed-function oxidases; the principal urinary metabolite is 3-alpha-hydroxy-1-methylen-5-alpha-androstan-17-one, excreted as glucuronide and sulfate conjugates. The sulfate-conjugated metabolites provide extended detection windows in anti-doping analysis, with some metabolites detectable for several weeks after a single administration. Metenolone exhibits low affinity for sex hormone-binding globulin (SHBG), approximately 16 percent of that of testosterone and 3 percent of that of DHT, resulting in a higher fraction of unbound drug in plasma.

    Adverse effects are consistent with the anabolic-androgenic steroid class but are generally milder than those of 17-alpha-alkylated compounds. Virilization in female patients (acne, hirsutism, voice deepening, clitoral enlargement, menstrual irregularity) is the principal androgenic concern. Suppression of endogenous gonadotropin secretion (luteinizing hormone and follicle-stimulating hormone) produces dose-dependent hypothalamic-pituitary-gonadal axis suppression with consequent testicular atrophy, oligospermia, and reduced endogenous testosterone production in male users. Cardiovascular effects include unfavorable shifts in the lipoprotein profile (decreased high-density lipoprotein cholesterol, increased low-density lipoprotein cholesterol), though these shifts are generally less pronounced than those produced by 17-alpha-alkylated oral steroids. Hepatotoxicity is minimal at therapeutic doses, consistent with the absence of C17-alpha-alkylation. This monograph reviews the chemistry, synthesis, and structural pharmacology of metenolone; the androgen receptor mechanism and tissue-selective pharmacodynamics; the complete pharmacokinetic profile of both ester forms; the clinical evidence base across hematologic, catabolic, and body-composition indications; sourcing and quality verification; reconstitution and handling; stack interactions; adverse events; and a comparative assessment of five alternative anabolic-androgenic steroids against Primobolan on five competency standards.

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  • Telmisartan

    Non-peptide angiotensin II type 1 receptor antagonist with selective partial peroxisome proliferator-activated receptor gamma agonism

    A biphenyl-benzimidazole angiotensin II receptor blocker developed at Boehringer Ingelheim, distinguished from other sartans by intrinsic partial agonist activity at the nuclear peroxisome proliferator-activated receptor gamma and downstream metabolic, anti-inflammatory, and neuroprotective activity.

    Abstract

    Telmisartan is a non-peptide, orally active antagonist of the angiotensin II type 1 receptor (AT1R) and a selective partial agonist of the nuclear peroxisome proliferator-activated receptor gamma (PPARgamma), approved by the United States Food and Drug Administration in 1998 for the treatment of hypertension and subsequently for cardiovascular risk reduction in patients intolerant to angiotensin-converting enzyme inhibitors. The compound is marketed as Micardis (Boehringer Ingelheim) and is available in extensive generic competition worldwide. Among the eight clinically marketed angiotensin II receptor blockers (ARBs), telmisartan is distinguished by three pharmacological and pharmacokinetic features: the longest terminal elimination half-life (approximately 24 hours), the largest volume of distribution (approximately 500 liters), and a structurally defined partial agonist interaction with PPARgamma that is not shared at clinically meaningful potency by any other marketed sartan. The PPARgamma partial agonism, first formally characterized by Benson et al. (2004) in a systematic screen of ARBs against nuclear receptor panels, produces downstream modulation of carbohydrate and lipid metabolism gene expression, reduction of insulin resistance markers, suppression of NF-kappaB-driven proinflammatory cytokine release, and enhancement of adiponectin secretion, all at concentrations achieved by the registered 80 mg oral dose [1]. These pleiotropic activities extend the pharmacological profile of telmisartan substantially beyond the hemodynamic consequences of AT1R blockade and have driven a preclinical and clinical research literature encompassing metabolic syndrome, type 2 diabetes prevention, neuroprotection, renoprotection, and anti-inflammatory applications.

    The clinical evidence base for telmisartan is anchored by two landmark randomized controlled trials. The ONTARGET trial (Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial; N = 25,620) demonstrated that telmisartan 80 mg daily was non-inferior to ramipril 10 mg daily on a composite cardiovascular endpoint of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure in high-risk patients, with superior tolerability and fewer treatment discontinuations [2]. The TRANSCEND trial (Telmisartan Randomised Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease; N = 5,926) demonstrated that telmisartan modestly reduced the composite of cardiovascular death, myocardial infarction, or stroke compared with placebo in ACE-inhibitor-intolerant patients, leading to the 2009 FDA supplemental indication for cardiovascular risk reduction [3]. Additional large-scale trials include PRoFESS (Prevention Regimen for Effectively Avoiding Second Strokes; N = 20,332), which evaluated telmisartan for secondary stroke prevention, and DETAIL (Diabetics Exposed to Telmisartan and Enalapril; N = 250), which demonstrated renoprotective non-inferiority to enalapril in type 2 diabetic patients with early nephropathy.

    Pharmacokinetics are characterized by dose-dependent oral bioavailability (42 percent at 40 mg, 58 percent at 160 mg), negligible cytochrome P450-mediated metabolism (less than 3 percent of the dose is glucuronidated; the remainder is excreted unchanged in bile and feces), a terminal elimination half-life of approximately 24 hours supporting once-daily dosing, and greater than 99.5 percent plasma protein binding. The compound is poorly soluble in water but freely soluble in dimethyl sulfoxide and dimethylformamide. Telmisartan does not require dose adjustment for renal impairment but should be used with caution in severe hepatic impairment owing to the predominantly biliary elimination pathway.

    This monograph reviews the chemistry, synthesis, and structural pharmacology of telmisartan; the dual AT1R antagonist and PPARgamma partial agonist mechanism in molecular detail; the comprehensive human pharmacokinetic record; the preclinical pharmacology across cardiovascular, metabolic, neuroprotective, and renoprotective models; the clinical evidence base across all studied indications; sourcing and quality verification considerations; reconstitution and handling for laboratory use; stack-interaction implications; adverse-event signal; and a structured comparative assessment of five alternative ARBs (losartan, valsartan, irbesartan, olmesartan, candesartan) against telmisartan on five competency standards.

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    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.

  • Vesugen

    Synthetic tripeptide bioregulator (Lys-Glu-Asp) targeting vascular endothelial gene expression through epigenetic modulation

    A Khavinson-class synthetic tripeptide bioregulator derived from vascular wall protein sequences, characterized by epigenetic modulation of endothelial proliferation markers, endothelin-1 normalization, sirtuin-1 upregulation, and neuroprotective gene regulation in preclinical aging and Alzheimer’s disease models.

    Abstract

    Vesugen (Lys-Glu-Asp; KED) is a synthetic tripeptide bioregulator developed at the Saint Petersburg Institute of Bioregulation and Gerontology under the direction of Professor Vladimir Khavinson as part of a decades-long program investigating short-chain peptide regulation of age-associated tissue decline. The compound belongs to the Khavinson class of ultrashort (two to four amino acid residue) bioregulatory peptides, a family of synthetic sequences derived from organ-specific protein fractions that are proposed to penetrate cell nuclei and modulate gene expression through direct interactions with DNA promoter regions and epigenetic regulatory mechanisms. Vesugen is the synthetic analog corresponding to the vascular-wall-derived peptide fraction originally isolated as the active component of Ventfort, a polypeptide complex extracted from bovine aortic tissue. The tripeptide sequence Lys-Glu-Asp was identified as the minimal bioactive motif responsible for the vasoprotective activity of the parent extract.

    The molecular pharmacology of Vesugen is characterized by epigenetic modulation of vascular endothelial cell function. In dissociated human endothelial cell cultures, Vesugen stimulates synthesis of the proliferation-associated protein Ki-67, the expression of which declines during cellular aging [1]. Molecular docking studies demonstrate that Vesugen binds to the promoter region of the MKI67 gene, making contact through the CATC sequence at the core promoter located between positions -14 and +12 relative to the transcription initiation site [1]. In models of atherosclerotic and restenotic endothelium in vitro, Vesugen normalizes the expression of endothelin-1, restores connexin (Cx37, Cx43) expression for intercellular communication, and increases sirtuin-1 (SIRT1) expression, implicating the compound in DNA repair and cellular longevity pathways [2, 3]. The compound also modulates expression of vascular endothelial growth factor (VEGF) and the apoptosis marker p53, contributing to a net pro-proliferative and anti-apoptotic phenotype in aged vascular endothelial cells.

    Beyond its primary vascular target, Vesugen has demonstrated neuroprotective activity in several preclinical models. The tripeptide regulates expression of cell aging and apoptosis genes (p16, p21), neuronal differentiation genes and proteins (NES, GAP43, nestin), and genes implicated in Alzheimer’s disease pathogenesis (SUMO, APOE, IGF1) [4]. In hippocampal neuron cultures exposed to amyloid-beta synaptotoxicity, Vesugen increased the number of mushroom-type dendritic spines by 20 percent [5]. Oral administration of Vesugen improved memory and attention in elderly individuals with functional central nervous system disorders in a small clinical cohort [4]. In a 32-patient clinical study of elderly individuals with chronic polymorbidity and organic brain syndrome, Vesugen demonstrated anabolic properties and improved central nervous system activity, slowing the rate of aging as measured by biological age indicators [6].

    The compound is not approved by any national regulatory authority as a pharmaceutical product. It is supplied as a research-grade synthetic peptide and as a dietary supplement (capsule form) in certain jurisdictions. The primary literature on Vesugen originates predominantly from Russian research institutions, principally the Saint Petersburg Institute of Bioregulation and Gerontology and affiliated laboratories. Independent replication by Western laboratories using contemporary structural biology and pharmacology methodologies remains limited. This monograph reviews the chemistry, proposed mechanism of action, preclinical pharmacology, limited clinical evidence, sourcing and handling considerations, and a comparative assessment against five alternative vasoprotective and geroprotective peptide candidates.

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    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.

  • Clenbuterol

    Selective beta-2 adrenergic receptor agonist with anabolic, lipolytic, and bronchodilatory activity

    A long-acting phenylaminoethanol beta-2 adrenoceptor agonist developed at Boehringer Ingelheim as a bronchodilator, distinguished from other sympathomimetic beta-agonists by exceptional oral bioavailability, a prolonged elimination half-life of 25 to 39 hours, and potent repartitioning activity on skeletal muscle and adipose tissue that has driven extensive preclinical and clinical investigation in muscle-wasting disorders, body composition, and neuromuscular disease.

    Abstract

    Clenbuterol (4-amino-alpha-[[(1,1-dimethylethyl)amino]methyl]-3,5-dichlorobenzyl alcohol; NAB 365) is a selective, long-acting beta-2 adrenergic receptor agonist originally synthesized in 1967 at the Thomae research facility of Boehringer Ingelheim in Biberach, Germany, and approved in 1976 in that country for the treatment of reversible airway obstruction in asthma and chronic obstructive pulmonary disease. The compound acts through stimulation of the beta-2 adrenoceptor, a seven-transmembrane G-protein-coupled receptor that activates adenylyl cyclase, elevates intracellular cyclic adenosine monophosphate, and engages protein kinase A signaling cascades in airway smooth muscle, skeletal muscle, adipose tissue, and hepatocytes. In airway smooth muscle the principal consequence is bronchodilation; in skeletal muscle and adipose tissue the consequences are protein accretion and lipolysis, respectively, producing a body-composition repartitioning effect that has generated an extensive preclinical and applied research literature spanning livestock science, sports pharmacology, and clinical investigation in muscle-wasting disease.

    Pharmacokinetics in humans are characterized by rapid oral absorption (bioavailability approximately 70 to 80 percent), minimal hepatic first-pass metabolism, a prolonged terminal elimination half-life of 25 to 39 hours (substantially longer than the structurally related short-acting beta-2 agonists salbutamol and terbutaline), and predominant renal excretion of unchanged drug. The extended half-life supports once- or twice-daily oral dosing and produces measurable plasma accumulation on chronic administration, reaching steady state in approximately 4 days. Five minor metabolites have been identified in human and animal studies, none with significant pharmacological activity at the beta-2 receptor.

    The compound is approved for human bronchospastic indications in multiple European and Latin American jurisdictions but has never received approval from the United States Food and Drug Administration for human use. In the United States, clenbuterol hydrochloride is approved solely for veterinary use as Ventipulmin Syrup (Boehringer Ingelheim Vetmedica) for the management of airway obstruction in horses, under a New Animal Drug Application approved by the FDA in 1998. The compound is classified as a prohibited substance under the World Anti-Doping Agency Prohibited List (category S1.2, other anabolic agents) and is banned in competition and out-of-competition in all sports under the WADA Code. Its use as a growth-promoting agent in food-producing animals is prohibited in the European Union, the United States, and China, though enforcement challenges have produced recurring food-safety incidents.

    Beyond the registered bronchodilator indication, the principal research applications of clenbuterol are in neuromuscular disease, where pilot and open-label clinical trials have demonstrated safety and preliminary efficacy signals in spinal and bulbar muscular atrophy, amyotrophic lateral sclerosis, and spinal muscular atrophy; in skeletal muscle physiology, where the compound is the reference beta-2 agonist for studying adrenergic regulation of protein synthesis, proteolysis, and fiber-type transitions; and in cardiac biology, where the compound has been studied as a bridge-to-recovery adjunct in patients with heart failure supported by left ventricular assist devices. The cardiac research application is notable given the concurrent identification of dose-dependent myocardial toxicity in animal models and in clinical case reports of supratherapeutic use, producing a narrow therapeutic index for cardiac applications that remains an active area of investigation.

    This monograph reviews the chemistry, synthesis, and stereochemistry of clenbuterol; the receptor pharmacology and downstream signaling; the comprehensive human pharmacokinetic record; preclinical pharmacology across muscle, adipose, and cardiac tissue; the clinical evidence base across bronchospastic, neuromuscular, cardiac, and body-composition indications; sourcing and quality verification considerations; reconstitution and handling; stack-interaction implications; adverse-event signal including cardiac toxicity; and a structured comparative assessment of five alternative beta-2 adrenergic agonists against clenbuterol on five competency standards.

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  • Mirodenafil

    Selective phosphodiesterase type 5 (PDE5) inhibitor of the pyrrolopyrimidinone structural class

    A second-generation pyrrolopyrimidinone PDE5 inhibitor developed by SK Chemicals in South Korea for erectile dysfunction, distinguished from first-generation agents by approximately 10-fold higher PDE5 affinity, superior isoenzyme selectivity, and an emerging multimodal research profile in Alzheimer’s disease through cGMP/PKG/CREB signaling, autophagy enhancement, and neuroinflammatory modulation.

    Abstract

    Mirodenafil (SK3530) is a potent, selective, and reversible inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) belonging to the pyrrolopyrimidinone structural class. Developed by SK Chemicals Life Science (Seongnam, South Korea) and approved in 2007 by the Korea Ministry of Food and Drug Safety for the treatment of erectile dysfunction, mirodenafil is marketed as Mvix in 50 mg and 100 mg oral tablet formulations and as a 50 mg orally dissolving film. The compound inhibits PDE5 with an IC50 of 0.34 nmol/L, approximately 10-fold more potent than sildenafil (IC50 3.5 nmol/L), and exhibits selectivity ratios of approximately 48,235-fold over PDE1, 254,000-fold over PDE3, and greater than 10,000-fold over PDE11. The PDE6 selectivity ratio is approximately 30-fold, intermediate between sildenafil and tadalafil but clinically associated with a low incidence of visual disturbance at therapeutic doses. Pharmacokinetically, mirodenafil is rapidly absorbed after oral administration with a time to maximum plasma concentration of 0.67 to 1.5 hours, an elimination half-life of 1.32 to 3.0 hours, oral bioavailability of 24 to 43 percent for the parent compound, and approximately 97 percent plasma protein binding. Metabolism is predominantly hepatic through CYP3A4-mediated N-dealkylation to the active metabolite SK-3541, which retains approximately one-tenth of the PDE5 inhibitory activity of the parent compound. Clinical efficacy in erectile dysfunction has been demonstrated in multiple randomized, double-blind, placebo-controlled trials totaling more than 700 patients across general, diabetic, and hypertensive populations, with improvements in the International Index of Erectile Function erectile function domain score of 7 to 12 points over placebo. Adverse events are predominantly mild to moderate, with flushing (3.3 to 24.1 percent) and headache (1.8 to 14.8 percent) as the most common; no visual disturbances or myalgia have been reported in published trials. Beyond erectile dysfunction, mirodenafil (designated AR1001 by licensee AriBio) has entered clinical development for Alzheimer’s disease on the basis of preclinical evidence demonstrating multimodal neuroprotective activity: activation of the cGMP/PKG/CREB signaling pathway, enhancement of autophagy-lysosome clearance of amyloid-beta and phosphorylated tau, suppression of neuroinflammation, and improvement of mitochondrial function. A Phase 2 randomized placebo-controlled trial in 210 patients with mild to moderate Alzheimer’s disease reported that AR1001 30 mg daily as monotherapy produced a statistically significant 4.019-point improvement on the ADAS-Cog 13 at 26 weeks (p = 0.012) with concurrent reductions in plasma phosphorylated tau-181 and tau-217 biomarkers. The global Phase 3 POLARIS-AD trial, enrolling approximately 1,150 participants with early Alzheimer’s disease across 200 sites under FDA, EMA, and MHRA authorization, is currently underway with a primary endpoint of change in Clinical Dementia Rating Sum of Boxes at 52 weeks. This monograph reviews the chemistry, pharmacology, pharmacokinetics, clinical evidence, sourcing, handling, stack interactions, safety profile, and comparative positioning of mirodenafil against five PDE5 inhibitor alternatives.

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  • PRL-8-53

    Substituted phenethylamine benzoate ester with hypermnesic (memory-enhancing) activity and mixed dopaminergic-cholinergic-serotonergic pharmacology

    A synthetic amino ethyl meta-benzoic acid methyl ester developed at Creighton University in the 1970s as a novel psychotropic agent, distinguished by a single double-blind human study demonstrating statistically significant enhancement of verbal memory retention at a 5 mg oral dose, and by a nearly complete absence of follow-up clinical investigation despite favorable acute tolerability and a high therapeutic index in animal models.

    Abstract

    PRL-8-53 (methyl 3-[2-[benzyl(methyl)amino]ethyl]benzoate hydrochloride) is a synthetic substituted phenethylamine and benzoate ester first synthesized by Nikolaus R. Hansl at Creighton University in the early 1970s as part of a systematic exploration of amino ethyl meta-benzoic acid esters for spasmolytic and psychotropic activity. The compound is classified as a hypermnesic agent on the basis of a single published double-blind, placebo-controlled human study (Hansl and Mead, 1978) in which a 5 mg oral dose produced statistically significant improvement in the retention of serially presented verbal material in 47 healthy volunteers, with the most pronounced effects observed in subjects over 30 years of age who had below-average baseline recall performance. The magnitude of the retention enhancement was substantial: subjects in the over-30 subgroup demonstrated approximately 108 percent improvement in 24-hour recall and 152 percent improvement in one-week recall relative to their placebo performance, with most P values better than 0.01 and some better than 0.001. The compound did not significantly alter visual reaction time or motor control at the studied dose, suggesting a selective cognitive action rather than generalized central nervous system stimulation.

    The molecular pharmacology of PRL-8-53 remains incompletely characterized. Preclinical evidence from Hansl’s laboratory and from the patent literature (US 3,870,715; granted March 11, 1975) indicates that the compound potentiates dopaminergic neurotransmission, partially inhibits serotonergic activity, and displays possible cholinergic properties. In animal models, PRL-8-53 reverses reserpine-induced catatonia and ptosis, improves avoidance learning in conditioned response paradigms, and exhibits spasmolytic activity against acetylcholine-, barium chloride-, and histamine-induced smooth muscle contraction. The compound does not exhibit stimulant properties at doses up to 200 mg/kg in rodents and does not potentiate the locomotor effects of dextroamphetamine at 20 mg/kg. The oral median lethal dose in mice is approximately 860 mg/kg, conferring a therapeutic index of approximately 170 relative to the projected human-equivalent dose, and chronic toxicology studies in rats, dogs, and monkeys through two offspring generations revealed no evidence of organ pathology or teratogenicity.

    Despite these promising early findings, no additional controlled human studies have been published since the 1978 report. The compound’s development was interrupted by Hansl’s retirement from Creighton University and a 1985 institutional dispute that resulted in the loss of stored experimental materials. The patent expired in approximately 1992, placing the compound in the public domain. Formal pharmacokinetic characterization in humans has not been published; the plasma elimination half-life is estimated at 2 to 4 hours on the basis of the compound’s structural properties and the time course of cognitive effects observed in the Hansl study. The metabolic pathways, routes of elimination, plasma protein binding, and blood-brain barrier penetration characteristics remain uncharacterized. PRL-8-53 is not approved by any regulatory authority for any indication. It is available as a research-grade preparation from multiple chemical suppliers at greater than 98 percent purity; investigators should obtain independent analytical confirmation of identity and purity on every lot. This monograph reviews the chemistry, synthesis, and structural classification of PRL-8-53; the available preclinical pharmacology; the single published human study in detail; the limited pharmacokinetic information; sourcing and quality verification; reconstitution and handling; stack-interaction considerations; adverse-event and safety signal; and a structured comparative assessment of five nootropic memory-enhancing compounds against PRL-8-53 on five competency standards.

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    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.

  • SM-04554

    Small-molecule Wnt/beta-catenin signaling pathway activator for topical dermatological application

    A synthetic 1,4-diketone Wnt pathway activator developed by Samumed (Biosplice Therapeutics) as a topical treatment for androgenetic alopecia, distinguished by its mechanism of follicular Wnt/beta-catenin signaling restoration and hair follicle neogenesis capacity in preclinical models, advanced through Phase 3 clinical evaluation before discontinuation.

    Abstract

    SM-04554, also designated dalosirvat (International Nonproprietary Name), is a synthetic small-molecule activator of the canonical Wnt/beta-catenin signaling pathway developed by Samumed, LLC (subsequently renamed Biosplice Therapeutics, Inc.) as a topical treatment for androgenetic alopecia (AGA). The compound activates Wnt signaling with an EC50 of approximately 28 to 29 nanomolar in cell-based reporter assays, producing increases in total and nuclear beta-catenin, versican expression, and Ki-67 proliferation marker specifically in hair follicle compartments. The molecular formula is C18H16O4 with a molecular weight of 296.32 g/mol; the compound is a 1,4-diketone bearing a 2,3-dihydro-1,4-benzodioxin-6-yl moiety and a terminal phenyl group, conferring moderate lipophilicity (calculated XLogP 2.6) suitable for topical scalp formulation.

    The mechanistic rationale for SM-04554 in androgenetic alopecia rests on the observation that Wnt/beta-catenin signaling is essential for the initiation and maintenance of the anagen (growth) phase of the hair cycle and that progressive reduction of Wnt pathway activity in the dermal papilla and hair bulge stem cell niche is a molecular correlate of follicular miniaturization in AGA. SM-04554 activates the pathway downstream of ligand-receptor interaction, increasing nuclear translocation of beta-catenin and transcription of Wnt target genes including those regulating dermal progenitor cell differentiation toward the hair follicle lineage. In preclinical models, topical SM-04554 induced hair follicle neogenesis in CD1 and C57BL/6 mice (2-fold increase in total follicle count after 4 days of treatment) and in Hanford mini-pigs (significant increase in vellus follicle number sustained through 112 days of observation following a 42-day treatment course).

    Clinical development proceeded through Phase 1 (29 subjects, 14-day topical application at 0.05%, 0.15%, and 0.45% concentrations), Phase 2 (two studies: a 49-subject biopsy-endpoint trial and a 300-subject efficacy trial, both 90-day treatment), and Phase 3 (625-subject registration trial initiated November 2018 and completed January 2021). The Phase 1 trial demonstrated safety with only one drug-related adverse event (eye irritation at the 0.45% concentration). The Phase 2 program demonstrated statistically significant increases in non-vellus hair count and density at the 0.15% concentration relative to vehicle, with an inverted-U dose-response in which the 0.15% concentration outperformed the higher 0.25% concentration. Adverse events across the Phase 2 program were mild (scalp redness, burning, stinging) and comparable in frequency to vehicle. No serious adverse events were reported in any treated patient across the Phase 2 program. The Phase 3 trial results were not publicly disclosed; Biosplice Therapeutics removed SM-04554 from its development pipeline in 2021, and a 2023 literature review confirmed cancellation of development based on Phase 3 outcomes. The compound is not approved by any regulatory authority.

    SM-04554 is one component of a broader Wnt-modulating therapeutic platform developed by Samumed/Biosplice, which includes lorecivivint (SM-04690, a CLK2/DYRK1A kinase inhibitor for knee osteoarthritis) and SM-04755 (a Wnt pathway inhibitor for tendinopathy). The compound is available from multiple research chemical suppliers as a white powder at greater than 99% purity. This monograph reviews the chemistry, Wnt pathway pharmacology, preclinical hair growth models, the complete clinical evidence base across all trial phases, pharmacokinetic considerations for topical delivery, sourcing and handling, stack-interaction considerations, adverse-event profile, and a comparative assessment of five alternative androgenetic alopecia candidates against SM-04554 on five competency standards.

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  • Sulforaphane

    Plain-language summaryIntrigue 72 / 100

    Sulforaphane is an isothiocyanate from broccoli sprouts that potently activates Nrf2, the master regulator of antioxidant gene expression. Has shown chemopreventive effects in cancer research and is being studied for autism spectrum disorder. 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.

    Isothiocyanate organosulfur compound and potent Nrf2 pathway activator derived from glucoraphanin in cruciferous vegetables

    A dietary isothiocyanate first isolated from broccoli at Johns Hopkins University as the most potent naturally occurring inducer of mammalian phase 2 cytoprotective enzymes, now established as a multimechanistic agent acting through Keap1-Nrf2 electrophilic signaling, NF-kappaB suppression, and histone deacetylase inhibition across chemopreventive, metabolic, neurobehavioral, and anti-inflammatory research applications.

    Abstract

    Sulforaphane (1-isothiocyanato-4-methylsulfinylbutane) is a low-molecular-weight isothiocyanate generated by myrosinase-catalyzed hydrolysis of the glucosinolate glucoraphanin, found at highest concentration in broccoli sprouts and at progressively lower concentration in mature broccoli, Brussels sprouts, cauliflower, and other cruciferous vegetables. First identified in 1992 by Paul Talalay and colleagues at the Johns Hopkins University School of Medicine as the most potent naturally occurring inducer of mammalian phase 2 detoxification enzymes, sulforaphane has become the most extensively studied dietary isothiocyanate in human pharmacology and the reference compound for nutrigenomic Nrf2 activation. The primary molecular mechanism is electrophilic modification of reactive cysteine residues on the Kelch-like ECH-associated protein 1 (Keap1) sensor, leading to stabilization and nuclear translocation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and subsequent transcriptional upregulation of a battery of cytoprotective genes including NAD(P)H:quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), glutathione S-transferases (GSTs), and thioredoxin reductase. Sulforaphane activates Nrf2 with a potency approximately 13-fold greater than curcumin, 18-fold greater than silymarin, and over 100-fold greater than resveratrol in standardized NQO1 inducer assays. A second established mechanism is the suppression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) signaling through inhibition of IkappaB-alpha phosphorylation and degradation, producing broad anti-inflammatory activity. A third mechanism, characterized by Myzak et al. in 2004, is inhibition of histone deacetylase (HDAC) enzymes by the mercapturic acid pathway metabolites sulforaphane-cysteine and sulforaphane-N-acetylcysteine, producing epigenetic reactivation of tumor suppressor genes including p21 and Bax. Pharmacokinetics in humans are characterized by rapid oral absorption (peak plasma concentration within 1 to 3 hours), a short elimination half-life of approximately 1.8 to 2.2 hours, extensive metabolism through the mercapturic acid (glutathione conjugation) pathway, and urinary excretion of 60 to 80 percent of administered sulforaphane equivalents within 24 hours. Oral bioavailability of free sulforaphane is approximately 70 to 80 percent, while bioavailability from the glucoraphanin precursor is approximately 10 to 40 percent depending on myrosinase activity and interindividual variation in gut microbial glucosinolate hydrolysis. Over 80 interventional clinical trials have examined sulforaphane or sulforaphane-yielding preparations in human subjects across indications including cancer chemoprevention (prostate, breast, lung, colorectal, bladder), autism spectrum disorder, type 2 diabetes, schizophrenia, chronic obstructive pulmonary disease, Helicobacter pylori infection, and air pollution detoxification. The Singh et al. (2014) randomized placebo-controlled trial in young men with moderate to severe autism spectrum disorder demonstrated substantial and reversible behavioral improvement on the Aberrant Behavior Checklist and Social Responsiveness Scale after 18 weeks of daily sulforaphane administration. The Axelsson et al. (2017) trial in obese patients with dysregulated type 2 diabetes demonstrated reduced fasting blood glucose and improved glycated hemoglobin with concentrated broccoli sprout extract. The compound is generally well tolerated; the principal adverse events are mild gastrointestinal disturbance (flatulence, bloating, loose stools). Goitrogenic potential at high doses is a theoretical concern for individuals with pre-existing thyroid dysfunction. This monograph reviews the chemistry, biosynthesis, and stereochemistry of sulforaphane; the tripartite molecular pharmacology (Keap1-Nrf2, NF-kappaB, HDAC); comprehensive human pharmacokinetics; the preclinical and clinical evidence base across chemopreventive, metabolic, neurobehavioral, and anti-inflammatory indications; sourcing and quality verification; reconstitution and handling; stack-interaction considerations; adverse-event and safety signal; and a comparative assessment of five alternative Nrf2-activating or cruciferous-derived cytoprotective compounds against sulforaphane on five competency standards.

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  • Aticaprant

    Selective kappa-opioid receptor (KOR) antagonist with short-acting, non-inactivating pharmacodynamic profile

    A potent, orally bioavailable aminobenzyloxyarylamide kappa-opioid receptor antagonist developed at Eli Lilly and advanced through Phase 3 clinical evaluation for adjunctive treatment of major depressive disorder with anhedonia, distinguished from earlier KOR antagonists by favorable drug-like properties, short-acting receptor blockade, and a well-characterized safety profile.

    Abstract

    Aticaprant (LY-2456302, CERC-501, JNJ-67953964) is a potent, selective, orally bioavailable antagonist of the kappa-opioid receptor (KOR) with a binding affinity (Ki) of 0.81 nM, approximately 30-fold selectivity over the mu-opioid receptor (Ki = 24.0 nM), and approximately 190-fold selectivity over the delta-opioid receptor (Ki = 155 nM). The compound belongs to the aminobenzyloxyarylamide chemical class and was designed at Eli Lilly Research Laboratories as a clinically viable therapeutic targeting the endogenous dynorphin/KOR neuromodulatory system, a pathway implicated in the pathophysiology of stress-induced anhedonia, dysphoria, and addictive behaviors. In contrast to earlier KOR antagonists such as JDTic and nor-binaltorphimine, which exhibit ultra-long-duration receptor inactivation persisting for weeks after a single dose, aticaprant produces short-acting, reversible KOR blockade with an elimination half-life of 30 to 40 hours, enabling conventional once-daily oral dosing and predictable pharmacokinetic management.

    The preclinical pharmacology of aticaprant was characterized in the seminal Rorick-Kehn et al. (2014) report, which demonstrated that oral administration selectively and potently occupied central KOR in vivo (ED50 = 0.33 mg/kg) without evidence of mu- or delta-opioid receptor occupancy at doses up to 30 mg/kg. In rodent behavioral models, aticaprant produced antidepressant-like effects in the mouse forced swim test, enhanced the efficacy of imipramine and citalopram, reduced ethanol self-administration in alcohol-preferring (P) rats, and reversed unpredictable chronic mild stress-induced anhedonia in C57BL/6J mice, as measured by sucrose preference, nest building, and forced swim endpoints. Positron emission tomography (PET) imaging in humans confirmed near-complete saturation of brain KOR at a 10 mg oral dose (94% receptor occupancy at 2.5 hours post-dose), with sustained occupancy (82% at 24 hours for a 25 mg dose), supporting the translational pharmacology from preclinical models to human central nervous system target engagement.

    Clinical development of aticaprant has proceeded through multiple sponsors. Eli Lilly conducted the initial Phase 1 single- and multiple-ascending dose studies (Lowe et al. 2014), establishing safety, tolerability, and the absence of clinically significant interactions with ethanol. Cerecor Inc. acquired the compound in 2015 and initiated early clinical studies in mood and substance use disorders. Janssen Pharmaceuticals (Johnson and Johnson) acquired the compound in 2017 and advanced it through Phase 2 and Phase 3 programs for adjunctive treatment of major depressive disorder (MDD) in patients with inadequate response to selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). The Phase 2 randomized, double-blind, placebo-controlled study (Jacobsen et al. 2024) in 181 participants with MDD and moderate-to-severe anhedonia demonstrated a statistically significant reduction of 2.1 points on the Montgomery-Asberg Depression Rating Scale (MADRS) for aticaprant 10 mg versus placebo (p = 0.04), with favorable tolerability and no new safety signals. However, the compound did not separate from placebo on secondary measures of anhedonia (Snaith-Hamilton Pleasure Scale), global illness severity (CGI-S), anxiety (HAM-A), or patient-reported depression outcomes.

    Janssen subsequently initiated the VENTURA Phase 3 program comprising five pivotal trials in MDD with anhedonia. On 6 March 2025, Johnson and Johnson announced discontinuation of the VENTURA program due to insufficient efficacy in the target population, while noting that the compound remained safe and well tolerated with no new safety signals detected. The most common treatment-emergent adverse events in clinical trials were headache (11.8% versus 7.1% placebo), diarrhea (8.2% versus 2.4%), nasopharyngitis (5.9% versus 2.4%), and pruritus (5.9% versus 0%). Johnson and Johnson has indicated that it will explore future development opportunities for aticaprant in other areas of high unmet need. The compound is not approved by any regulatory authority for any indication. This monograph reviews the chemistry, synthesis, receptor pharmacology, pharmacokinetics, preclinical and clinical evidence base, sourcing and quality considerations, reconstitution and handling, stack interactions, adverse-event profile, and a comparative assessment of five KOR antagonist candidates against aticaprant on five competency standards.

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  • Compound-7p

    Sulfonamidoacetamide small-molecule inducer of axon regeneration and neurite outgrowth

    A synthetic sulfonamidoacetamide identified through phenotypic cell-based screening and structure-activity optimization as a potent inducer of neurite outgrowth in hippocampal, cortical, and retinal primary neurons, with demonstrated in vivo axon regeneration activity in an optic nerve crush injury model.

    Abstract

    Compound 7P (CAS 1890208-58-8) is a synthetic sulfonamidoacetamide with the systematic name 2-[(2-methoxyphenyl)[(4-methylphenyl)sulfonyl]amino]-N-(4-methoxy-3-pyridinyl)acetamide and molecular formula C22H23N3O5S (molecular weight 441.50 g/mol). The compound was identified at Hanyang University (Republic of Korea) through a phenotypic cell-based screening campaign of chemical libraries followed by iterative structure-activity-guided optimization, culminating in its characterization as the lead compound in a 2016 Journal of Medicinal Chemistry report by Ku, Park, Lee, and colleagues [1]. Compound 7P promotes neurite outgrowth in cultured primary neurons derived from the hippocampus, cerebral cortex, and retina, and in an in vivo rat model of optic nerve crush injury it induces the growth of GAP-43-positive regenerating axons at distances extending beyond 1500 micrometers distal to the crush epicenter, a finding that demonstrates translation of the in vitro neurite outgrowth phenotype into bona fide central nervous system axon regeneration.

    The compound was selected as the optimization lead on the basis of three convergent improvements over the parent hit (compound 1): enhanced neurite outgrowth activity in the primary neuron phenotypic assay, improved aqueous solubility attributable to the introduction of a 4-methoxypyridinyl amide pharmacophore replacing a lipophilic aniline, and markedly improved metabolic stability (61.2 percent of parent compound remaining after microsomal incubation, compared to 0.7 percent for the original hit) driven by reduction of the calculated partition coefficient from 3.76 to 2.43 [1]. These properties rendered compound 7P suitable for the in vivo optic nerve injury study that constitutes the principal translational evidence for the compound class.

    The molecular target or targets through which compound 7P stimulates axon regeneration have not been definitively identified. The phenotypic screening approach that generated the compound was target-agnostic, and the published literature does not report a defined receptor, enzyme, or signaling node as the primary binding partner. Contextual evidence from the broader axon regeneration field implicates pathways including the mammalian target of rapamycin (mTOR), the signal transducer and activator of transcription 3 (STAT3), and phosphatase and tensin homolog (PTEN) signaling as determinants of central nervous system axon growth competence, but the specific engagement of these pathways by compound 7P has not been demonstrated in pathway-deconvolution or target-identification studies.

    Compound 7P has no clinical development history. No human pharmacokinetic, safety, or efficacy data have been generated. The compound is not approved by any regulatory authority for any indication. It has entered the research-chemical supply chain as a nootropic-marketed powder on the basis of the published preclinical neurite outgrowth and axon regeneration data, but no clinical evidence supports cognitive enhancement, neuroprotection, or any other therapeutic claim in humans. This monograph documents the chemistry, structure-activity optimization, published preclinical pharmacology, the limited mechanistic and pharmacokinetic characterization, sourcing and handling considerations, and a comparative assessment against five alternative axon-regeneration-promoting small molecules on five competency standards. Investigators should treat compound 7P as an early-stage preclinical research tool with a single peer-reviewed primary publication and no human translational data.

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