ISOLATION OF NOVEL PARA-PENTYL PHENYL BENZOATE FROM MONDIA WHITEI. (HOOK.F.) SKEELS (PERIPLOCACEAE), ITS STRUCTURE, SYNTHESIS AND NEUROPHARMACOLOGICAL EVALUATION

Ethnomedicinal, phytochemical, pharmacological and toxicological profile of Mondia whitei: A review

Mondia whitei is an aromatic plant native to sub-Saharan Africa. This spice is commonly used in the treatment of various diseases, such as hypertension, diabetes, erectile dysfunction, and premature ejaculation. This review was undertaken to provide updated information on the botanical, phytochemical, pharmacological, and toxicological knowledge of this plant of high relevance to African populations. Moreover, its mechanism of action was described based on previous experimental studies. Data were compiled from various online databases such as PubMed, Google Scholar, Scopus, Science Direct, Web of Science, Springer link, Taylor and Francis, and SciFinder. Additionally, books, book chapters and proceedings were used as secondary sources. The chemical structures of phytocompounds were drawn using PubChem Sketcher program. M. whitei contains various phytocompounds, including reducing sugars, triterpenes, steroids, alkaloids, saponins, tannins, phenolics, hydrogen cyanide, carotenoid, oxalate and phytate. Moreover, para-pentylphenyl-benzoate, (-)-Loliolide, 5-chloropropacin, propacin, 2-hydroxy-4-methoxybenzaldehyde, isovanillin, 9-hexacosene, 2-hexen-1-ol, and heptacosane were isolated from this spice. M. whitei has several pharmacological benefits, including aphrodisiac, pro-fertile, pro-erectile, androgenic, antioxidant, antiparasitic, antimalarial, antibacterial, antiviral, antifungal, antiepileptic, anti-inflammatory, analgesic, antidepressant, antidiarrheal, hepatoprotective, antisickling, and anticancer activities. Toxicological studies showed an LD50 of above 5000 mg/Kg and no signs of toxicity after one week of oral treatment. The aphrodisiac effect of this spice is one of its main activities, supported by numerous experimental studies. Because M. whitei delays contractions of the bulbospongiosus muscles, its aphrodisiac effect could be mediated through the modulation of the spinal generator of ejaculation. This can justify its folkloric use in the treatment of premature ejaculation.

Structure-Dependent Activity of Natural GABA(A) Receptor Modulators

GABA(A) receptors are ligand-gated ion channels consisting of five subunits from eight subfamilies, each assembled in four hydrophobic transmembrane domains. This pentameric structure not only allows different receptor binding sites, but also various types of ligands, such as orthosteric agonists and antagonists, positive and negative allosteric modulators, as well as second-order modulators and non-competitive channel blockers. A fact, that is also displayed by the variety of chemical structures found for both, synthetic as well as nature-derived GABA(A)-receptor modulators. This review covers the literature for natural GABA(A)-receptor modulators until the end of 2017 and discusses their structure-activity relationship.