Rothtalazepane, A New Azepane from the Wood of Rothmannia talbotii (Rubiaceae)

Abstract

Rothmannia talbotii, a hitherto chemically unexplored medicinal plant, is used in the Western Region of Cameroon to relieve fever. In our ongoing search for bioactive compounds from Cameroonian medicinal plants, a previously undescribed compound rothtalazepane (1), along with six known compounds, aitchisonide B (2), D-mannitol (3), β-D-glucopyranosyl-(6→1’)-β-D-glucopyranoside (4), monopalmitin (5), stigmasterol (6), and sitosterol 3- O-β-D-glucopyranoside (7) were isolated and characterized from the crude ethanol extract of the wood of R. talbotii. Rothtalazepane (1) exhibits no significant activity against several microbial strains, thus its function likely lies not in antimicrobial defense and it is not the active principle against urinary infections described for Rothmannia.

Elemane‐Type Sesquiterpene, Acetonide Derived Polyacetylene and Other Constituents from the Whole Plant of Gymnanthemum theophrastifolium (Schweinf. ex Oliv. & Hiern) H.Rob. and Their Chemophenetic Significance

“…However, phytochemical screening of extracts from G. coloratum revealed the presence of alkaloids, anthocyanins, cardenolids, coumarins, flavonoids, glycosides, leucoanthocyanins, and terpenoids amongst others [7] . In our continuous search for secondary metabolites with biological importance from Cameroonian medicinal plants, [8–13] we undertook the first ever investigation of G. theophrastifolium with a double objective to isolate the compounds from the whole plant extract and compare them with those of the genus Vernonia in order to draw their chemophenetic importance to the description of the genus Gymnanthemun . We herein report the structure elucidation of two new compounds including the elemane‐type sesquiterpenoid ( 1 ) and polyacetylene ( 2 ), and the naturally occurring compound ( 3 ) from the plant kingdom along with sixteen known compounds ( 4 – 19 ).…”

Toward the Allelopathy of Peganum sp. and Related Chemical Constituents in Agriculture

“…The context of the research in Africa in respect to the subject is discussed. This survey follows our continued search for the application of plant extracts and constituents as principal feedstocks in the development of drugs and allelochemicals (Koagne et al, 2017;Nganou et al, 2019b;Tchinda et al, 2019;Mbaveng et al, 2020;Ben Mrid et al, 2021;Damen et al, 2021). The core of pool documents examined for this review was provided from SciFinder-n and PubMed or ScienceDirect when entering the references "Peganum and activities" and refining the search with different concepts including fungicides, proteins, growth and development, plant, insecticides, lipid peroxidation, herbicides, phytopathogens, seedling, and phytotoxicity.…”

Sesquiterpene Lactones from Vernonia tufnelliae: Structural Characterization and Biological Evaluation

“…Compound 1 contains an unprecedented 10/5/5/6 tetracyclic moiety featuring a hexahydro-1 H ,3 H ,7 H -furo­[3′,4′:3,4]­furo­[3,2- c ]­pyridin-1-one unit linked to a typical cyclodecane ring of germacrene, while compound 2 is the first elemane–germacranolide heterodimer ever to have been found in Nature. The present report is part of an ongoing research initiative on bioactive metabolites from Cameroonian folk medicine. − …”

“…20−22 Thus, compound 1 bears a new nitrogen-containing 10/5/ 5/6 tetracyclic scaffold where both germacranolide-like fragments of compound 1 are linked through a tertiary nitrogen, as supported by the HMBC cross-peaks from H-13′ (δ H 2.90) to carbon C-13 (δ C 54.0) and the odd molecular mass obtained for 1. A 1 H, 15 N-HMBC spectrum was recorded but turned out to be featureless due to a too low signal/noise ratio. Thus, compound 1 is a member of the sesquiterpenoid alkaloid group, with the origin of nitrogen as well as its biosynthesis not fully understood.…”