Aristolactams, 1-(2-C-Methyl-β-D-ribofuranosyl)-uracil and Other Bioactive Constituents of Toussaintia orientalis

Abstract

The new aristolactam alkaloid toussalactam {2-hydroxy-1,6-dimethoxy-5H-dibenzo[cdf]indol-4-one} and the known ones, namely aristolactam AII, aristolactam BII, piperolactam C and aristolactam FII; 1-(2-C-methyl-β-D-ribofuranosyl)-uracil, 3,4,5-trimethoxyphenyl-β-D-glucopyranoside, and three catechinoids were isolated from the cytotoxic Toussaintia orientalis Verdc stem and root bark extracts, and their structures established based on analysis of spectroscopic data. The aristolactams exhibited antimicrobial and antiinflammatory activity, aristolactam FII showing almost the same level of activity as the standard anti-inflammatory agent Indomethacin. The compounds also exhibited either mild or no antiproliferative and cytotoxic activities, except aristolactam FII that showed the same level of cytotoxicity as the standard drug Camptothecin. 1-(2-C-Methyl-β-D-ribofuranosyl)-uracil, which is being reported for the first time as a natural product, was inactive in the antibacterial, antifungal, antiinflammatory, antiproliferative and cytotoxicity assays.

Naturally occurring aristolochic acid analogues and their toxicities

“…The compound showed an effect on anti-platelet aggregation in vitro.Toussalactam 88 was isolated from Toussaintia orientalis Verdc. (Annonaceae) and showed antimicrobial and anti-inammatory effects 142. Caldensine 89, an N-aristolactam previously unknown from natural sources was isolated for the rst time from Piper caldense C. DC.…”

N-Cinnamoyltetraketide Derivatives from the Leaves of Toussaintia orientalis

“…The cinnamide amido proton (δ H 6.67) couples to methine H-5 (δ H 4.78), which in turn couples to the diastereotopic methylene H-6a and H-6b (δ H 3.20, 2.40) and to the oxymethine H-3 (δ H 3.81) through a W-coupling, frequently observed for 1,3-diequatorial protons of cyclohexanes. Thus, this 4 J coupling reveals the equatorial orientation of both H-3 and H-5 in the preferred conformation of the cyclohexanone ring of 6 (Figure 3). Vicinal coupling is observed between H-3 (δ H 3.81) and the diastereotopic methylene H-2a (δ H 3.08) and H-2b (δ H 2.69).…”

“…Its roots mixed with lion skin are boiled to produce a concoction that is applied as a remedy for the treatment of asthma and skin rashes arising from abdominal worms, whereas its leaves mixed with chicken feathers are burnt, with the resulting ashes being mixed with coconut oil to treat irritating rashes. 2 Recent phytochemical investigations of T. orientalis serendipitously uncovered myriads of new bioactive metabolites, 1,4,5 among others bioactive N-cinnamoyltetraketides having α,βunsaturated cyclohexenoid, tetrahydrobenzofuranoid, or indolidinoid skeletons amidated with a cinnamoyl moiety. 1,6 These structural units are commonly found in antituberculotic, 7 cytostatic, 8 antimalarial, and cardioprotective compounds.…”

“…Recent phytochemical investigations of T. orientalis serendipitously uncovered myriads of new bioactive metabolites, ,, among others bioactive N -cinnamoyltetraketides having α,β-unsaturated cyclohexenoid, tetrahydrobenzofuranoid, or indolidinoid skeletons amidated with a cinnamoyl moiety. , These structural units are commonly found in antituberculotic, cytostatic, antimalarial, and cardioprotective compounds . As part of our ongoing work on the phytochemical characterization of East African medicinal plants, we report the isolation, identification, and the cytotoxic and antimycobacterial activities of three new and four known N -cinnamoyltetraketide derivatives isolated from the leaves of T. orientalis .…”

Natural indole‐containing alkaloids and their antibacterial activities

“…Besides the above‐mentioned mono‐indole‐containing alkaloids, several other indole‐containing alkaloids were also isolated from various natural sources, but all of them were inactive or only displayed a weak activity against the tested bacteria. [ 56–93 ] For example, paraherquamide J ( 30 ), a new prenylated indole‐containing alkaloid from the marine‐derived fungus Penicillium janthinellum HK1–6, was devoid of activity against both Gram‐positive ( S. aureus , E. faecalis , and E. faecium ) and Gram‐negative ( E. coli ) pathogens. [ 93 ]…”