Germacranolides and a New Type of Guaianolide from Acanthospermum hispidum

Abstract

The aerial parts of an Argentinian collection of Acanthospermum hispidum afforded 26 sesquiterpene lactones, including the two guaianolides (1 and 2) having a novel oxygen bridge between C-4 and C-14, three new cis,cis-germacranolides (4, 7, and 8), and two new melampolides (25 and 26). Guaianolides 1 and 2 seem to derive biosynthetically from the germacranolide 27 having the (1)D(14, 15)D(5) conformation. The structures were elucidated using extensive spectroscopic analysis.

Ethnobotanical survey and cytotoxicity testing of plants of South-western Nigeria used to treat cancer, with isolation of cytotoxic constituents from Cajanus cajan Millsp. leaves

“…The observed activity of the methanol extract may be due to the terpenoid and polyphenolic components of the plant since earlier studies describe the in vitro and in vivo cytotoxicity of melampolides and cis,cis-germacranolides obtained from the related species Acanthospermum glabratum (Nair et al, 1985;Jakupovic et al, 1986;Cartagena et al, 2000).…”

Novel Sesquiterpenoids from Siegesbeckia orientalis

“…The known compounds 2-methylbut-2-enoic acid (3aS,4S,5S,6Z,10Z,11aR)-5-(acetyloxy)-2,3,3a,4,5,8,9,11a-octahydro-6,10-bis(hydroxymethyl)-3-methylene-2-oxocyclodeca[b]furan-4-yl ester (4) [19], lecocarpinolide (F) 5 [20], and (4b,10E)-6a,14,15-trihydroxy-8b-(isobutyryloxy)germacra-10,11(13)-diene-12-oic acid 12,6-lactone (10) [18] isolated from this plant were identified by comparison of their spectral data with those reported. …”

Antitrichomonal activity of Acanthospermum hispidum D. C. (Asteraceae)

“…The plant has been reported to possess sesquiterpene lactones such as acanthospermal B, acanthospermal B epoxide, hispidunolide A and B (Herz and Kalyanaraman, 1975;Jakupovic et al, 1986;Kraus et al, 1994;Cartagena et al, 2000;Arena et al, 2011). In addition, glycosides and flavonoids have been reported to be present in the aerial part of the plant (Nair et al, 1976;Edewor and Olajire, 2011).…”