Author: kodiac

  • Aminotadalafil

    Synthetic phosphodiesterase type 5 (PDE5) inhibitor analog; tadalafil N-methyl-to-amino substituted derivative

    A synthetic structural analog of tadalafil in which the piperazinedione N-methyl group is replaced by a primary amine, yielding an unapproved phosphodiesterase type 5 inhibitor principally encountered as an undeclared adulterant in dietary supplements marketed for erectile dysfunction.

    Abstract

    Aminotadalafil, formally (6R,12aR)-2-amino-6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydropyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione (CAS 385769-84-6), is a synthetic structural analog of tadalafil, the selective cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) inhibitor marketed as Cialis for the treatment of erectile dysfunction, pulmonary arterial hypertension, and benign prostatic hyperplasia. The single structural modification that distinguishes aminotadalafil from the parent drug is the replacement of the N-methyl substituent on the 2-position of the piperazinedione (diketopiperazine) ring with a primary amino group (NH2), a change that alters hydrogen-bonding capacity, basicity, and physicochemical properties while preserving the core beta-carboline-fused diketopiperazine scaffold responsible for PDE5 active-site recognition. Aminotadalafil retains inhibitory activity at PDE5 and exhibits greater than 100 percent cross-reactivity with anti-tadalafil polyclonal antibodies, confirming close structural and immunochemical homology with the parent compound [1]. The compound has not undergone formal preclinical toxicology, human pharmacokinetic characterization, or clinical efficacy evaluation in any regulatory jurisdiction, and it is not approved for human use by any national medicines authority. Its principal significance in the biomedical literature arises from its repeated identification as an undeclared adulterant in dietary supplements, herbal products, and electronic cigarette liquids marketed for sexual enhancement, where it poses uncharacterized risks to consumers who are unaware of its presence and who may be concurrently taking nitrate-containing medications or other agents that interact with the cGMP-nitric oxide signaling pathway [2, 3, 4, 5].

    The analytical chemistry literature on aminotadalafil is substantial. The compound has been identified and structurally characterized by proton and carbon-13 nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and ultraviolet spectrophotometry in dietary supplement matrices across multiple continents, including reports from Latin America, Asia, Europe, and North America [2, 6, 7]. Validated high-performance liquid chromatography with diode array detection (HPLC-DAD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods permit simultaneous identification and quantification of aminotadalafil alongside other PDE5 inhibitor analogs (hydroxythiohomosildenafil, thiosildenafil, dimethylsildenafil, thiodimethylsildenafil) in complex supplement matrices [3, 8]. A dimeric interaction product of aminotadalafil has also been isolated from adulterated health food products, suggesting that the compound undergoes degradation or condensation reactions under storage conditions encountered in supplement manufacture [9].

    The pharmacological characterization of aminotadalafil is limited. No peer-reviewed study has reported a direct IC50 determination for aminotadalafil against recombinant human PDE5, and no selectivity panel across the eleven mammalian phosphodiesterase families has been published. The compound’s activity is inferred from its structural homology to tadalafil (IC50 approximately 1.8 to 5.0 nanomolar against PDE5) and from the immunochemical cross-reactivity data. Structure-activity relationship studies of the broader tadalafil analog series indicate that modifications at the 2-position of the diketopiperazine ring modulate PDE5 affinity, and that the (6R,12aR) stereochemistry derived from L-tryptophan is essential for potent inhibition [10, 11]. Aminotadalafil preserves this stereochemistry. No human pharmacokinetic, dose-response, or safety data exist; toxicological risk assessment must therefore rely on extrapolation from tadalafil and on the general pharmacology of the PDE5 inhibitor class. This monograph reviews the chemistry, structural pharmacology, inferred pharmacokinetics, regulatory history, detection methodology, sourcing considerations, and comparative assessment of aminotadalafil against five alternative PDE5 inhibitor analogs encountered in the adulterated supplement landscape.

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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.

  • Arimistane

    Steroidal mechanism-based (suicide) aromatase inhibitor derived from the 7-oxo-dehydroepiandrosterone metabolic pathway

    A naturally occurring androstadienedione metabolite of 7-keto-DHEA that functions as an irreversible steroidal aromatase inactivator, distinguished from pharmaceutical aromatase inhibitors by its endogenous biosynthetic origin and concurrent reported activity on cortisol regulation through competitive inhibition of 11-beta-hydroxysteroid dehydrogenase type 1.

    Abstract

    Androsta-3,5-diene-7,17-dione, marketed and commonly known as Arimistane, is a steroidal mechanism-based irreversible inhibitor of aromatase (cytochrome P450 19A1, CYP19A1) that occupies a distinctive position in the landscape of estrogen-modulating compounds. Structurally, it is an androstadienedione bearing conjugated 3,5-diene unsaturation in the A/B ring system and a 7-oxo group on the B ring, with the characteristic 17-ketone of the androstane series. The compound is a downstream metabolite of 7-keto-dehydroepiandrosterone (7-keto-DHEA, 3-beta-hydroxyandrost-5-ene-7,17-dione), itself produced from dehydroepiandrosterone (DHEA) by hepatic cytochrome P450 7B1 (CYP7B1) or CYP3A-mediated 7-alpha-hydroxylation followed by 11-beta-hydroxysteroid dehydrogenase (11-beta-HSD) oxidation at the 7-position and subsequent dehydration. This endogenous biosynthetic origin distinguishes Arimistane from fully synthetic aromatase inhibitors such as exemestane, letrozole, and anastrozole.

    The aromatase-inhibitory mechanism of Arimistane belongs to the type I (steroidal, mechanism-based) class characterized by Covey and colleagues in the early 1980s for the structurally related androst-5-ene-7,17-dione series [1, 2]. Mechanism-based inhibition proceeds through initial competitive binding of the steroidal inhibitor to the substrate-binding pocket of aromatase, followed by enzyme-catalyzed oxidative processing that generates a reactive intermediate capable of forming a covalent bond with amino acid residues at or near the active site. The covalent modification permanently inactivates the enzyme molecule; restoration of aromatase activity requires de novo protein synthesis rather than simple inhibitor dissociation. This irreversible (“suicide”) mechanism produces sustained estrogen suppression that persists beyond the plasma residence time of the parent compound, a pharmacodynamic feature shared with the clinically approved steroidal aromatase inactivator exemestane.

    Beyond aromatase inhibition, Arimistane has been reported to modulate cortisol metabolism through competitive inhibition of 11-beta-hydroxysteroid dehydrogenase type 1 (11-beta-HSD1), the microsomal enzyme that catalyzes the reduction of cortisone to the biologically active glucocorticoid cortisol in liver, adipose tissue, and central nervous system. This activity, attributed to the 7-oxo-androstane structural motif shared with 7-keto-DHEA and its metabolites, is proposed to reduce local cortisol regeneration without affecting adrenal cortisol synthesis directly. The dual aromatase-inhibitory and cortisol-modulatory profile has driven interest in Arimistane within the bodybuilding and sports-performance supplement industry, where the compound has been marketed as a post-cycle therapy agent and estrogen-control supplement.

    The regulatory status of Arimistane is restrictive. The United States Food and Drug Administration (FDA) has determined that androsta-3,5-diene-7,17-dione does not meet the statutory definition of a dietary ingredient under section 201(ff)(1) of the Federal Food, Drug, and Cosmetic Act, and has issued multiple warning letters to supplement manufacturers marketing products containing the compound [3]. The World Anti-Doping Agency (WADA) added Arimistane to the Prohibited List in 2017 under the category of hormone and metabolic modulators (class S4), specifically as an aromatase inhibitor [4]. The compound is not approved as a pharmaceutical in any jurisdiction.

    The clinical evidence base for Arimistane is sparse relative to pharmaceutical aromatase inhibitors. No registration-quality clinical trials have been conducted. Published human data are limited to manufacturer-sponsored tolerability assessments and analytical chemistry studies characterizing the compound as a urinary metabolite of 7-keto-DHEA in anti-doping contexts [5]. The pharmacological characterization rests principally on in vitro aromatase inhibition assays, structure-activity relationship inference from the broader androstene-7,17-dione series studied by Covey, Brodie, and colleagues in the 1980s and 1990s [1, 2, 6], and extrapolation from the more extensive clinical pharmacology of the structurally related steroidal aromatase inactivator exemestane. This monograph reviews the chemistry, biosynthetic origin, mechanism of aromatase inactivation, reported pharmacokinetics, preclinical and clinical evidence, sourcing and quality considerations, stack interactions, adverse-event signal, and a comparative assessment of Arimistane against five alternative aromatase-modulating compounds 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.

  • Topilitumide

    Topical nonsteroidal antiandrogen of the perfluoroacylamido-arylpropanamide class with rapid serum hydrolysis and local androgen receptor suppression

    A rationally designed, serum-labile topical antiandrogen engineered from the flutamide scaffold for androgen receptor suppression in dermal tissue without systemic absorption, developed by Biophysica Inc. and marketed as Eucapil for androgenetic alopecia in Central European jurisdictions.

    Abstract

    Topilutamide (International Nonproprietary Name; also known as fluridil and by the development code BP-766) is a nonsteroidal antiandrogen of the perfluoroacylamido-arylpropanamide structural class, rationally designed for topical application in the treatment of androgenetic alopecia. The compound represents a deliberate medicinal chemistry solution to the principal limitation of systemic nonsteroidal antiandrogens such as flutamide, bicalutamide, and enzalutamide: hepatotoxicity and sexual adverse effects arising from systemic androgen receptor blockade. The design strategy incorporated perfluoroalkyl moieties into the flutamide analog BP-34 to produce a molecule that retains high-affinity androgen receptor antagonism and androgen receptor protein downregulation in dermal tissue while undergoing rapid hydrolytic decomposition upon contact with human serum (half-life approximately 6 hours at 37 degrees Celsius; undetectable after 48 hours), yielding the inactive fragments BP-34 and trifluoroacetic acid. Neither parent compound nor metabolites have been detected in human serum following chronic topical application at the marketed 2 percent concentration, establishing a pharmacokinetic profile that functionally eliminates systemic antiandrogenic exposure.

    In vitro pharmacology in LNCaP human prostate cancer cells demonstrates concentration-dependent suppression of androgen receptor protein expression: approximately 40 percent reduction at 3 micromolar and up to 95 percent reduction at 10 micromolar following 48-hour incubation [1, 2]. Comparative binding studies suggest that topilutamide binds the androgen receptor with approximately 9- to 15-fold greater affinity than bicalutamide and hydroxyflutamide, though these findings require further validation with rigorous competitive binding assays [2]. The mechanism appears to involve both direct receptor antagonism and receptor protein downregulation, distinguishing topilutamide from pure competitive antagonists that stabilize the receptor in an inactive conformation.

    The clinical evidence base is limited to two published trials comprising 53 total participants. The pivotal randomized, double-blind, placebo-controlled trial in 43 men with androgenetic alopecia demonstrated significant promotion of anagen-phase hair growth: anagen percentage increased from 75.7 percent to 85.1 percent at 3 months and 87 percent at 9 months with daily topical application of 2 percent fluridil in isopropanol vehicle [3]. Sexual function, libido, hematology, and blood chemistry values remained within normal limits throughout the study period, and no systemic absorption of the parent compound or its metabolites was detectable. A second open-label study in 11 women with female pattern hair loss demonstrated significant increases in hair shaft diameter at 6 and 9 months but did not achieve statistical significance on anagen-telogen ratio endpoints [4]. The compound was introduced for cosmetic use in 2003 and is marketed exclusively in the Czech Republic and Slovakia by Interpharma Praha (a subsidiary of Otsuka Pharmaceutical) under the brand name Eucapil. It is not approved by the United States Food and Drug Administration, the European Medicines Agency, or any other major regulatory authority for pharmaceutical use. The patent expired in 2020. This monograph reviews the chemistry, synthesis, rational design strategy, androgen receptor pharmacology, pharmacokinetics and serum lability, preclinical toxicology, the clinical evidence base, sourcing and handling considerations, comparator assessment against five alternative androgenetic alopecia agents, and the safety profile of topilutamide.

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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.

  • Retinalamin

    Polypeptide bioregulator complex derived from bovine retinal tissue with retinoprotective and neurotrophic activity

    A tissue-derived polypeptide fraction developed at the St. Petersburg Institute of Bioregulation and Gerontology as a retinoprotective agent, distinguished from conventional neuroprotective ophthalmologics by its multi-peptide composition, tissue-specific gene expression regulation, and clinical application across glaucoma, diabetic retinopathy, and hereditary retinal dystrophies.

    Abstract

    Retinalamin is a complex of water-soluble polypeptide fractions with molecular weight not exceeding 10,000 daltons, isolated from bovine retinal tissue and developed as a retinoprotective peptide bioregulator by Vladimir Khavinson and colleagues at the St. Petersburg Institute of Bioregulation and Gerontology of the Russian Academy of Medical Sciences. The compound is registered in the Russian Federation and several Commonwealth of Independent States jurisdictions as a lyophilized preparation for parabulbar and intramuscular injection, manufactured by Geropharm LLC under the ATC code S01XA (other preparations for eye disease treatment). Retinalamin represents a distinct pharmacological class within ophthalmic neuroprotection: rather than a single molecular entity with a defined receptor target, it consists of a heterogeneous mixture of short-chain polypeptides (predominantly 2 to 7 amino acid residues in length) that act through tissue-specific modulation of gene expression, stimulation of intracellular protein synthesis, regulation of lipid peroxidation, and normalization of cellular membrane function in retinal photoreceptors, retinal pigment epithelium, and Mueller glial cells.

    The mechanistic basis of Retinalamin activity has been characterized through in vitro and in vivo models at the St. Petersburg Institute. In Xenopus laevis early gastrula ectoderm assays, Retinalamin demonstrated concentration-dependent induction of neuronal differentiation including brain, retinal, and pigment epithelium lineages, establishing the compound as a morphogenetic peptide regulator with tissue-specific inductive capacity. In cell culture, Retinalamin and the related synthetic tetrapeptide Epithalon stimulated proliferation of retinal and pigmented epithelial cells in a tissue-specific and concentration-dependent manner. The proposed molecular mechanism involves sequential binding of constituent short peptides to promoter regions of genes involved in retinal cell differentiation, survival, and metabolic homeostasis, thereby modulating transcriptional activity and downstream protein expression. Pharmacodynamic effects observed in preclinical and clinical settings include stimulation of photoreceptor and retinal cellular element function, improvement of functional interactions between retinal pigment epithelium and photoreceptor outer segments, enhancement of Mueller cell activity and glutamate inactivation, normalization of vascular permeability, and reduction of oxidative stress through regulation of lipid peroxide metabolism.

    Clinical evidence for Retinalamin spans multiple retinal pathologies. In compensated primary open-angle glaucoma, a 180-patient randomized controlled trial (Egorov et al. 2019) demonstrated that intramuscular Retinalamin produced significant retinoprotective effects, with improvement in mean deviation index from negative 5.52 to negative 4.82 decibels, stabilization of ganglion cell complex thickness (versus progressive thinning in controls), and preservation of pattern electroretinography amplitudes over the study period. A subsequent 147-patient randomized trial (Strakhov et al. 2020) demonstrated that biannual Retinalamin courses over 24 months arrested development of glaucomatous optic neuropathy, with retinal nerve fiber layer thickness remaining stable in treated patients versus declining from 83.5 to 76.7 micrometers in controls. In diabetic retinopathy, a 56-patient comparative study (Malakhova et al. 2024) provided objective structural and functional evidence of positive retinal changes with intramuscular Retinalamin in early-stage disease. In hereditary retinal dystrophies, long-term observational data (Razumovskiy et al.) demonstrated that a first course of Retinalamin improved visual acuity in 58.1 percent and visual fields in 64.5 percent of retinal degeneration patients, with repeated courses over 23 to 25 years preserving residual vision in 55.6 percent of patients and preserving object vision in 11.1 percent. In retinal abiotrophy, residual vision was preserved in 100 percent of treated cases. A 498-patient glaucoma study (Erichev et al. 2020) comparing intramuscular, retrobulbar, and combined administration routes demonstrated comparable efficacy across delivery methods, with total threshold retinal sensitivity increasing by 122 to 274 decibels across glaucoma stages.

    The safety profile of Retinalamin is characterized by low adverse event rates. The principal reported events are local injection site reactions (pain, redness, swelling) and rare hypersensitivity reactions including anaphylactic shock and angioneurotic laryngeal edema. The compound is contraindicated during pregnancy (absence of clinical safety data) and in pediatric populations under 18 years for most indications. Pharmacokinetic characterization in the conventional sense is not feasible owing to the multi-component polypeptide composition, which does not permit standard absorption, distribution, metabolism, and elimination analysis of individual constituents. The standard clinical regimen consists of 5 to 10 milligrams administered once daily by parabulbar or intramuscular injection for 5 to 10 days, with courses repeated every 3 to 6 months. Retinalamin is not approved by the United States Food and Drug Administration, the European Medicines Agency, or other major Western regulatory authorities. The clinical evidence base is derived predominantly from Russian-language literature published in Vestnik Oftalmologii and related journals. Investigators outside the Russian Federation should approach the compound as a research-grade peptide preparation requiring independent analytical verification and should interpret the clinical literature with attention to the methodological standards and reporting conventions of the source publications.

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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.

  • CB-03-01

    Topical steroidal androgen receptor antagonist with peripherally selective antiandrogen activity

    A synthetic pregnane steroid developed by Cosmo Pharmaceuticals (Cassiopea) as a topically applied, peripherally selective androgen receptor antagonist for the treatment of acne vulgaris and androgenetic alopecia, distinguished from systemic antiandrogens by rapid local metabolism to inactive cortexolone and minimal systemic bioavailability.

    Abstract

    CB-03-01 (clascoterone; cortexolone 17alpha-propionate; 11-deoxycortisol 17alpha-propionate) is a synthetic pregnane steroid that functions as a competitive antagonist of the androgen receptor (AR) with submicromolar potency (IC50 approximately 0.4 to 1 micromolar in AR transactivation assays) and peripheral selectivity conferred by rapid enzymatic hydrolysis to the inactive parent compound cortexolone (11-deoxycortisol) in human skin, plasma, and hepatic tissue. The compound was identified from a structure-activity series of cortexolone 17alpha-monoesters screened for topical antiandrogen activity in the hamster flank organ test, in which CB-03-01 demonstrated potency approximately four times greater than progesterone, three times greater than flutamide, two times greater than finasteride, and approximately equivalent to cyproterone acetate, while lacking systemic antiandrogenic, antianabolic, or glucocorticoid activity after subcutaneous administration in rats. The molecular pharmacology centers on competitive displacement of dihydrotestosterone (DHT) from the androgen receptor in sebocytes and dermal papilla cells, resulting in suppression of androgen-responsive gene transcription, reduction of sebaceous lipid synthesis, inhibition of inflammatory cytokine production (including interleukin-6), and attenuation of androgen-driven miniaturization of scalp hair follicles. In human dermal papilla cell cultures, CB-03-01 demonstrated significantly greater inhibition of DHT-stimulated IL-6 synthesis than the direct AR antagonist enzalutamide.

    The compound received its first regulatory approval from the United States Food and Drug Administration in August 2020 as a 1% topical cream (Winlevi) for the treatment of acne vulgaris in patients aged 12 years and older, representing the first new mechanism of action approved for acne in approximately 40 years and the first topical antiandrogen approved for acne in any jurisdiction. Two pivotal Phase 3 randomized, double-blind, vehicle-controlled trials enrolling a total of 1440 patients with moderate to severe facial acne demonstrated statistically significant treatment success rates (Investigator Global Assessment score of 0 or 1 with at least a two-grade reduction) of approximately 18 to 20 percent for clascoterone versus 7 to 9 percent for vehicle at 12 weeks, with concurrent reductions in both inflammatory and noninflammatory lesion counts. Long-term safety data through 12 months demonstrated a favorable tolerability profile dominated by local application site reactions (erythema, dryness, pruritus) without clinically meaningful systemic antiandrogen effects.

    A second clinical program in androgenetic alopecia (AGA) has advanced through Phase 2 dose-ranging studies (2.5%, 5%, and 7.5% solutions applied twice daily) demonstrating statistically significant improvements in target area hair count (TAHC) at 6 and 12 months, and into Phase 3 registration trials (SCALP-1 and SCALP-2) using a 5% topical solution in 1465 male patients with mild to moderate AGA. The Phase 3 topline results reported statistically significant improvements in TAHC relative to vehicle, with a 5.39-fold relative improvement in one study and a 1.68-fold relative improvement in the second, the divergence attributable to baseline hair count differences rather than inconsistent drug performance. The safety profile in the AGA trials was comparable to vehicle, with no evidence of systemic androgen blockade.

    Pharmacokinetics following topical application are characterized by minimal systemic absorption. At maximal clinical use conditions (6 grams of 1% cream applied twice daily), steady-state plasma concentrations of clascoterone average 3.1 plus or minus 1.9 ng/mL with Cmax values of 4.5 plus or minus 2.9 ng/mL. The compound is rapidly hydrolyzed in plasma to cortexolone, which is detectable at concentrations generally near or below the lower limit of quantitation (0.5 ng/mL). Plasma protein binding is 84 to 89 percent. The principal safety signal is reversible hypothalamic-pituitary-adrenal (HPA) axis suppression, observed in approximately 7 percent of adolescent and adult subjects in maximal-use pharmacokinetic studies, with all cases resolving within 4 weeks of discontinuation. This monograph reviews the chemistry, synthesis, and structural pharmacology of CB-03-01; the competitive androgen receptor antagonist mechanism in molecular detail; the pharmacokinetic profile including systemic absorption, metabolism, and HPA axis considerations; the preclinical pharmacology in hamster, rat, and human tissue models; the clinical evidence base across acne and androgenetic alopecia indications; sourcing and quality verification; reconstitution and handling; stack-interaction considerations; adverse-event signal; and a comparative assessment of five alternative antiandrogen or androgen-modulating agents against CB-03-01 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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    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.

  • Thymalin

    Plain-language summaryIntrigue 58 / 100

    Thymalin is a Russian-developed bovine thymus peptide preparation used as an immunomodulator for elderly patients and immune disorders. Combined with epitalon in Khavinson’s longevity research. 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.

    Thymic polypeptide bioregulator complex with immunomodulatory and geroprotective activity

    A heterogeneous polypeptide complex isolated from calf thymus, developed at the Military Medical Academy in Leningrad as a thymic bioregulator for immune restoration, distinguished from other thymic peptide preparations by its multicomponent composition containing the immunomodulatory dipeptides L-glutamyl-L-tryptophan and L-lysyl-L-glutamic acid and the tripeptide L-glutamyl-L-aspartyl-L-proline.

    Abstract

    Thymalin is a standardized polypeptide complex isolated from the thymus gland of calves by acid hydrolysis and ultrafiltration, containing peptide fractions in the 1,000 to 10,000 dalton molecular weight range. Developed at the Military Medical Academy in Leningrad (now Saint Petersburg) by Vladimir Khavinson and Vyacheslav Morozov in the 1970s, the preparation was registered as an immunomodulatory pharmaceutical in the Soviet Union in 1982 and has remained in clinical use in the Russian Federation for more than four decades. Unlike the structurally defined thymic peptides thymosin alpha-1 (a 28-amino-acid single-sequence peptide), thymulin (a zinc-dependent nonapeptide), and thymopentin (a synthetic pentapeptide fragment of thymopoietin), Thymalin is a multicomponent extract whose principal bioactive constituents have been identified by reversed-phase high-performance liquid chromatography as the dipeptide L-glutamyl-L-tryptophan (Glu-Trp, subsequently developed independently as Thymogen), the dipeptide L-lysyl-L-glutamic acid (Lys-Glu, developed as Vilon), and the tripeptide L-glutamyl-L-aspartyl-L-proline (Glu-Asp-Pro, developed as Crystagen). The molecular mechanism of the immunoprotective activity is attributed to the capacity of these short peptides to bind selectively to double-stranded DNA sequences and to histone proteins, thereby modulating chromatin conformation, gene expression, and the synthesis of immune system proteins including interleukins, interferons, heat-shock proteins, and components of the fibrinolytic system. In experimental systems, Thymalin stimulates the differentiation and functional activity of T-lymphocyte subpopulations (CD4+ and CD8+), normalizes the ratio of T-helper to T-suppressor cells, enhances natural killer cell activity and phagocytosis, and modulates the balance between pro-inflammatory and anti-inflammatory cytokines. The geroprotective properties of Thymalin are supported by a prospective clinical observation of 266 elderly subjects over 6 to 8 years conducted at the St. Petersburg Institute of Bioregulation and Gerontology and the Institute of Gerontology of the Ukrainian Academy of Medical Sciences, in which Thymalin-treated subjects exhibited 2.0- to 2.1-fold lower mortality compared to controls receiving standard geriatric care, with further reductions (4.1-fold lower mortality) observed in a subgroup receiving annual combined Thymalin and Epithalamin treatment for 6 years. More recently, a prospective randomized single-blind controlled trial of Thymalin (10 mg intramuscular daily for 10 days) in 80 elderly patients with severe COVID-19 reported a 92 percent increase in blood lymphocytes, 6.5-fold reduction in interleukin-6, halved in-hospital mortality (19.4 percent versus 40.9 percent in controls), and more rapid clinical improvement (80.5 percent versus 59 percent). In vitro studies have demonstrated that Thymalin reduces expression of the stem cell markers CD44 and CD117 by 2- to 3-fold while increasing expression of CD28 (a marker of mature T lymphocytes) by 6.8-fold, consistent with stimulation of hematopoietic stem cell differentiation into functional T cells. The compound is administered by intramuscular or subcutaneous injection in short cyclical courses of 5 to 10 days at doses of 5 to 10 mg daily, with clinical effect reported to persist for weeks to months following each treatment course. The safety record across more than 40 years of clinical use indicates minimal adverse events, principally limited to injection-site reactions. This monograph reviews the composition, extraction, and characterization of Thymalin; the molecular pharmacology of its constituent peptides at the level of DNA binding, histone interaction, and gene expression regulation; the pharmacokinetic properties; the preclinical evidence base across immune restoration, geroprotection, and oncology models; the clinical evidence in elderly immune decline, respiratory infections, perioperative immune suppression, and COVID-19; sourcing and quality verification considerations; reconstitution and handling protocols; stack interactions with other immunomodulatory agents; the adverse-event and safety profile; and a comparative assessment of five alternative thymic and immunomodulatory peptide preparations against Thymalin on five competency standards (novelty, effect size, promising potential, side-effect profile, and overall validation).

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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.

  • Cerebrolysin

    Plain-language summaryIntrigue 65 / 100

    Cerebrolysin is a porcine brain peptide hydrolysate used in Europe and Asia for stroke recovery and dementia. It contains a complex mixture of small peptides and amino acids. Available only as injection. 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.

    Porcine brain-derived neurotrophic peptide mixture with multimodal neuroprotective and neurorestorative activity

    A standardized enzymatic hydrolysate of porcine brain tissue yielding low-molecular-weight neuropeptides and free amino acids that cross the blood-brain barrier and exert neurotrophic, neuroprotective, and neuroplasticity-promoting effects across stroke, traumatic brain injury, and neurodegenerative disease models.

    Abstract

    Cerebrolysin is a standardized, injectable preparation of enzymatically derived low-molecular-weight neuropeptides and free amino acids obtained from porcine brain tissue, manufactured by EVER Neuro Pharma (formerly EBEWE Pharma) in Unterach, Austria. The preparation contains peptide fragments exclusively below 10,000 Daltons in molecular weight, including sequences homologous to brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), and ciliary neurotrophic factor (CNTF), together with approximately 15 percent free amino acids by mass. First developed in 1949 by Gerhard Harrer at the University of Graz and subsequently refined through enzymatic hydrolysis standardization at EBEWE Pharma beginning in 1972, the compound has been registered as a pharmaceutical product in over 50 countries (excluding the United States, Canada, the United Kingdom, and most Western European Union member states) for indications including stroke recovery, traumatic brain injury, and dementia syndromes.

    The pharmacological profile of Cerebrolysin is characterized by multimodal neurotrophic and neuroprotective activity. The constituent peptides activate tropomyosin receptor kinase (Trk) signaling pathways, particularly TrkA and TrkB, initiating downstream MAPK/ERK and PI3K/Akt cascades that regulate neuronal survival, differentiation, and synaptic plasticity. Additional characterized mechanisms include inhibition of calpain-mediated cytoskeletal degradation, suppression of excitotoxic glutamate signaling, reduction of free radical formation, attenuation of microglial activation, and promotion of neurogenesis in the subventricular zone and hippocampal dentate gyrus. The low molecular weight of the constituent peptides permits transit across the blood-brain barrier, a property that distinguishes Cerebrolysin from recombinant full-length neurotrophic factors that do not achieve meaningful central nervous system concentrations after peripheral administration.

    The clinical evidence base encompasses more than 200 clinical studies involving over 10,000 patients across stroke, traumatic brain injury, Alzheimer’s disease, vascular dementia, and pediatric neurodevelopmental indications. The Cerebrolysin and Recovery After Stroke (CARS) randomized, placebo-controlled, double-blind multicenter trial demonstrated large superiority of Cerebrolysin (30 mL per day for 21 days) over placebo on the Action Research Arm Test at day 90 (Mann-Whitney estimator 0.71, 95 percent confidence interval 0.63 to 0.79, P less than 0.0001). The Cerebrolysin Acute Stroke Treatment in Asia (CASTA) trial in 1,070 patients did not demonstrate superiority on the primary endpoint (National Institutes of Health Stroke Scale at day 90), although post hoc analysis in severe stroke (NIHSS greater than 12) showed a trend favoring Cerebrolysin. In Alzheimer’s disease, a meta-analysis of randomized controlled trials demonstrated significant improvement in cognitive function (standardized mean difference negative 0.40 on the ADAS-cog at 4 weeks) and global clinical change compared to placebo, with safety comparable to placebo. In traumatic brain injury, 27 clinical studies enrolling 9,752 patients have demonstrated improvements in consciousness level, cognitive performance, and neurological outcomes.

    The safety profile across controlled clinical trials is favorable, with adverse event rates comparable to placebo in most analyses. The principal adverse events are vertigo, agitation, feeling hot, headache, and dizziness. Rare anaphylactic reactions have been reported. The compound is contraindicated in epilepsy and severe renal impairment. This monograph reviews the composition, manufacturing, and quality standardization of Cerebrolysin; the multimodal neurotrophic and neuroprotective pharmacology; the pharmacokinetic profile including blood-brain barrier penetration; the clinical evidence base across all studied indications; sourcing and quality verification; reconstitution and handling; stack-interaction considerations; adverse-event signal; and a comparative assessment of five neurotrophic or neuroprotective alternatives (Cortexin, P21, NSI-189, Actovegin, Semax) against Cerebrolysin on five competency standards (novelty, effect size, promising potential, side-effect profile, and overall validation).

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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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    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.

  • Cortexin

    Plain-language summaryIntrigue 52 / 100

    Cortexin is a Russian-developed bovine cortex peptide hydrolysate, similar in concept to cerebrolysin but from cerebral cortex tissue rather than whole brain. Used in Russia for stroke and cognitive impairment. 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.

    Polypeptide bioregulator complex derived from cerebral cortex with neurotrophic, neuroprotective, and nootropic activity

    A heterogeneous low-molecular-weight neuropeptide preparation extracted from the cerebral cortex of young cattle and pigs, registered in the Russian Federation as a neuroprotective agent for cerebrovascular disorders, traumatic brain injury, cognitive impairment, and perinatal central nervous system lesions, distinguished from Cerebrolysin by cortex-specific sourcing and intramuscular administration.

    Abstract

    Cortexin is a lyophilized complex of water-soluble polypeptide fractions with molecular weights ranging from 1,000 to 10,000 Daltons, obtained by acetic acid extraction from the cerebral cortex of cattle and pigs younger than 12 months of age. The preparation contains predominantly acidic and neutral polypeptides (70 to 95 percent of total mass), free amino acids (including glutamic acid, aspartic acid, glycine, serine, lysine, and alanine as quantitatively predominant species), and trace quantities of vitamins, minerals, and fatty acids. Unlike single-sequence peptide therapeutics, Cortexin is a heterogeneous mixture without a defined primary structure, and its pharmacological activity is attributed to the collective action of multiple bioactive peptide fractions rather than to any single molecular entity.

    The compound was developed within the Soviet and subsequently Russian bioregulator research program led by Vladimir Khavinson at the Saint Petersburg Institute of Bioregulation and Gerontology beginning in the 1980s, with the first clinical applications in military and aerospace medicine. Cortexin received pharmaceutical registration in the Russian Federation in 1999 and is manufactured by GEROPHARM LLC (Saint Petersburg) as a lyophilisate for intramuscular injection at 5 mg and 10 mg strengths, with glycine (12 mg) as the stabilizing excipient. The compound is registered in Russia, Ukraine, Kazakhstan, Belarus, Uzbekistan, and several other Commonwealth of Independent States jurisdictions for the treatment of acute and chronic cerebrovascular disorders, traumatic brain injury, cognitive impairment, encephalopathy of various origins, epilepsy as adjunctive therapy, and perinatal central nervous system lesions in children. It is not registered or approved in the European Union, the United States, Japan, or any jurisdiction with International Council for Harmonisation regulatory standards.

    The molecular mechanisms of Cortexin are pleiotropic and incompletely characterized at the individual peptide level. Demonstrated activities include modulation of glutamatergic transmission through interaction with AMPA receptors, kainate receptors, and metabotropic glutamate receptors (mGluR1 and mGluR5); GABAergic modulation through GABA-A receptor binding; activation of neurotrophic signaling cascades including brain-derived neurotrophic factor and nerve growth factor pathways; antioxidant activity through restoration of pro-oxidant and antioxidant system balance; anti-inflammatory action at both cerebral and systemic levels; and anti-apoptotic effects on neurons under ischemic and excitotoxic stress. Radioactively labeled Cortexin peptides have been demonstrated to cross the blood-brain barrier in mice, supporting direct central nervous system activity. Neuron-specific proteins including beta-5-tubulin, creatine kinase B, and protein 14-3-3 alpha/beta have been identified as molecular partners of Cortexin peptides in brain tissue.

    The clinical evidence base for Cortexin is substantial within the Russian-language medical literature but limited in the international peer-reviewed literature. The largest body of evidence supports efficacy in acute ischemic stroke, where Cortexin at 10 mg twice daily intramuscularly for 10 days is included in Russian national clinical practice guidelines. A multicenter randomized controlled study (Fedin et al. 2018) demonstrated dose-dependent effects of Cortexin (10 mg versus 20 mg versus standard care alone) on neurological deficit severity, asthenia, and sleep disturbance in patients with chronic cerebral ischemia, with antioxidant effects confirmed by laboratory markers regardless of dose. A multicenter study of cognitive dysfunction in children demonstrated improvement in attention, visual memory, and thinking in pediatric patients with consequences of perinatal central nervous system lesions. In cerebral palsy with comorbid epilepsy, Cortexin as adjunctive therapy reduced seizure frequency by more than two-fold in 36.9 percent of patients while improving motor function. Comparative preclinical studies have demonstrated neuroprotective efficacy comparable to Cerebrolysin and superior to Actovegin in rat models of acute and chronic brain ischemia. A systematic review of animal-derived nootropics noted that the limited number of eligible Cortexin studies precluded meta-analysis, though available data suggested potential efficacy with no safety concerns. The compound is generally well tolerated; the principal adverse events are injection site reactions (8 to 15 percent), headache (5 to 12 percent), dizziness (3 to 8 percent), and rare hypersensitivity reactions including anaphylaxis. This monograph reviews the composition, extraction methodology, and physicochemical properties of Cortexin; the pleiotropic molecular pharmacology; the pharmacokinetic limitations inherent to a heterogeneous peptide preparation; the clinical evidence base across cerebrovascular, traumatic, cognitive, and pediatric indications; sourcing and quality verification considerations; reconstitution and handling protocols; stack-interaction implications; adverse-event signal; and a structured comparative assessment of five neuroprotective alternatives against Cortexin on five competency standards.

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