Simulaite Report

Objective: This study tested whether reported Sphenocentrum jollyanum marker compounds can explain the plant's reproductive and aphrodisiac phenotype through specific molecular targets, then benchmarked those findings against target-specific drugs and a Tongkat Ali validation benchmark.

Conclusion: The computational evidence now points away from a Viagra-like PDE5A mechanism, which would act directly on blood-flow signaling, and toward steroid-metabolism targets, which regulate how testosterone and related hormones are made or converted. In structural de-risking, pinnatasterone aligned best with the aromatase/

CYP19A1 testosterone pocket, columbamine aligned best with the 5α-reductase/SRD5A2 reference pocket, and pinnatasterone's PDE5A pose scored well in molecular docking but did not match the sildenafil/tadalafil inhibitor subpocket. Short explicit-solvent MD on the PDE5A pose supported the same interpretation: the ligand remained outside the sildenafil-like reference zone over the sampled trajectory.

The Tongkat Ali benchmark gives this interpretation useful context. Run independently, the Tongkat screen matched literature-supported eurycomanone aromatase/phosphodiesterase biology while keeping direct androgen-receptor binding weak versus steroid controls; the cited literature emphasizes aromatase/phosphodiesterase rather than direct androgen-receptor activation [1,2].

The practical takeaway is an assay shortlist, not a product claim: test CYP19A1 and SRD5A2 first (pinnatasterone and columbamine), evaluate PXR/CYP induction early, and treat PDE5A as a low-priority falsification target unless biochemistry surprises.

Sphenocentrum jollyanum is a West African medicinal plant with reported traditional use in male sexualperformance contexts and published reproductive animal studies [3,4,7]. Existing literature supports phenotype-level effects, including altered testosterone, aphrodisiac behavior, sperm-quality changes, and reproductive toxicity [4,7].

However, the available literature does not appear to resolve which isolated Sphenocentrum compounds interact with

specific endocrine or erectile-function targets.

This study was designed to address that gap by screening reported parent marker compounds against a focused male reproductive pharmacology panel, benchmarking the results against receptor-specific drugs, and applying structural pose de-risking so that binding scores are not interpreted as mechanism proof without reference-pocket alignment.

The screened Sphenocentrum marker panel included palmatine and columbamine alkaloids [4], columbin and isocolumbin furanoditerpenes [5], and 20-hydroxyecdysone and pinnatasterone ecdysteroids [6,8].

The Tongkat Ali validation panel included eurycomanone, eurycomanol, eurycomalactone, 13,21dihydroeurycomanone, canthin-6-one, and 9-methoxycanthin-6-one, plus target-relevant controls.

Reported marker compounds were evaluated against experimentally derived target pockets. Binding scores were used as ordinal plausibility signals. Lower, more negative scores indicate a more favorable predicted pose within the target pocket.

A second structural layer classified each docked marker against the co-crystal reference ligand on that target: ligand centroid distance to the reference subpocket (<=6 Å with required anchor contacts = reference-aligned), intermediate contact with offset centroid (partial), or weak/off-pocket placement. This step is essential for large phytoactive scaffolds, which often achieve favorable docking scores without matching the binding mode of the target-class drug.

For PDE5A, docked pinnatasterone underwent short explicit-solvent MD with pocket and ligand restraints. Analysis asked whether the ligand centroid approached the sildenafil (VIA) reference subpocket over the sampled trajectory; this was a consistency check on the static pose, not long-timescale potency validation.

All conclusions should be interpreted as computational prioritization, not biochemical confirmation. The goal was to identify which target hypotheses deserve experimental follow-up first.

Docking scores alone can overstate herbal mechanisms when large polycyclic markers fill hydrophobic enzyme pockets without matching the co-crystal drug pose. The table below summarizes static pharmacophore de-risking for Sphenocentrum markers on the six-target panel (reference ligand: TES on AR and CYP19A1, NDX/finasteride on SRD5A2, abiraterone on CYP17A1, VIA/sildenafil on PDE5A, SR12813 on PXR).

Interpretation rule used in this report: reference-aligned poses support target-specific assay planning; partial poses

(~6 Å from reference with some anchor contacts) support weak ordinal hypotheses only; CYP17A1 placements with very large centroid offsets are treated as docking failures, not biology.

Ranked PDE5A docked-pose comparison for tadalafil, pinnatasterone, avanafil, and sildenafil.

Molecular docking ranked pinnatasterone competitively on PDE5A, but static pharmacophore analysis placed it ~6.2

Å from the sildenafil (VIA) co-crystal centroid while retaining Gln817 and Phe820 contacts. Tadalafil met the inhibitor-subpocket criteria (~4.0 Å). Short explicit-solvent MD on docked pinnatasterone was consistent with the static result: the ligand centroid remained outside the <=6 Å VIA overlap zone over the sampled trajectory and did not show rapid entry into the reference inhibitor subpocket. PDE5A should therefore not headline the Sphenocentrum mechanism story; optional PDE5A biochemical testing remains useful only to falsify the erectiletarget hypothesis.

The most compelling Sphenocentrum hypothesis after de-risking is combined steroid-metabolism and endocrine- enzyme modulation rather than direct androgen receptor agonism or PDE5A-driven erectile pharmacology.

Aromatase/CYP19A1 is the cleanest structural efficacy hypothesis for pinnatasterone. It is reference-pocket aligned

(~2.8 Å from the testosterone co-crystal subpocket) with favorable anchor contacts. 20-hydroxyecdysone and isocolumbin also align on CYP19A1. This fits a testosterone-to-estrogen conversion axis upstream of receptor activation and parallels the aromatase emphasis in the Tongkat literature [1,2].

The figure below shows the quantum-computed electrostatic basis for this selectivity. Pinnatasterone carries electron-rich oxygen groups with computed partial charges of approximately −0.38 to −0.45 e. These groups are geometrically and electrostatically complementary to ARG115, the positively charged guanidinium residue in the CYP19A1 binding pocket, forming the same four anchor contacts (ARG115, PHE134, PHE221, TRP224) as the approved aromatase inhibitor exemestane. The androgen receptor, by contrast, presents an entirely hydrophobic binding core (PHE764, PHE876, PHE891, TRP741) with no ionic partner for the electron-rich oxygens, explaining the weaker predicted binding (2/4 contacts, −6.70 kcal/mol vs −8.97 kcal/mol on CYP19A1).

Electrostatic selectivity panel: pinnatasterone quantum-optimized geometry with partial-charge surface (left), compared to its binding pose in CYP19A1 alongside exemestane reference drug (top right) and the androgen receptor (bottom right).

SRD5A2 provides the second mechanistic route. SRD5A2 controls conversion of testosterone to dihydrotestosterone. Isocolumbin achieved the strongest docking score on SRD5A2, but static de-risking classifies it as partial (~6.6 Å from the finasteride reference subpocket). Columbamine is the best reference-aligned

Sphenocentrum marker on SRD5A2 (~4.9 Å). Assay planning should prioritize columbamine for structural plausibility and include isocolumbin as a docking-led follow-up with explicit pose uncertainty.

The PDE5A signal is a cautionary example of score-versus-mode divergence. Pinnatasterone scored below tadalafil

but above several approved PDE5 drugs in molecular docking, yet it does not reproduce the inhibitor pharmacophore/subpocket geometry that tadalafil and the co-crystal ligand satisfy. That pattern is common when large phytoactive scaffolds dock in the broader catalytic pocket without matching the drug binding mode. Erectilefunction claims should not rest on this target unless biochemistry contradicts the structural result.

CYP17A1 showed favorable docking scores for pinnatasterone but reference-centroid distances near ~29 Å, indicating off-pocket or unreliable poses under the current binding-site setup. Androgen-biosynthesis interpretation from CYP17A1 should wait on pose repair or orthogonal modeling.

The androgen receptor remains a secondary context. Columbin and several alkaloids show reference-aligned or near-aligned poses in the testosterone pocket, but steroid controls still dominate molecular docking. Direct AR agonism is not the primary story.

The PXR signal is best interpreted as a safety finding. PXR activation can induce drug-metabolizing enzymes and transporters. Strong docking by isocolumbin and related markers, together with mixed static alignment on PXR, indicates that a standardized, high-bioavailability extract concept would need CYP induction and drug-interaction evaluation before any product-facing claims.

Tongkat Ali was used as a validation comparator because it has a better-established reproductive mechanism literature. Published work on eurycomanone reports increased testosterone production in Leydig-cell models, inhibition of aromatase-mediated testosterone-to-estrogen conversion, and possible phosphodiesterase involvement at higher concentration [1]. Clinical literature on standardized Eurycoma longifolia extract supports testosterone-related effects in ageing men and summarizes eurycomanone-associated aromatase/ phosphodiesterase mechanisms [2]. These sources emphasize aromatase/phosphodiesterase biology rather than direct androgen-receptor activation.

This is an ordinal structural screen supplemented by static pharmacophore de-risking and a short PDE5A MD consistency check. It can prioritize hypotheses but cannot determine enzyme potency, receptor activation, tissue exposure, selectivity, metabolism, or clinical effect. The screened marker panel is representative rather than exhaustive, and additional reported Sphenocentrum constituents should be evaluated as follow-up candidates.

CYP17A1 results in this report are limited by off-pocket docking placements. PDE5A MD used restraints and a short sampled trajectory; it supports pose-class consistency only, not long-timescale binding stability or clinical efficacy.

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