Welwitschiilactone A, B and C, three new 30-norfriedelane triterpenes from the roots of Caloncoba welwitschii (Oliv.) Gilg (Achariaceae)

Publication date: October 2018Source: Phytochemistry Letters, Volume 27Author(s): Chimène Victoire Tchamadeu Keugwa, Jules Lobe Songue, Alain Tadjong Tcho, Alain François Kamdem Waffo, Jean Duplex Wansi, Jean Claude NdomAbstractThree new 30-norfriedelane triterpenoids named, 3β,21β-dihydroxy-27-oxo-30-nor-(D:A)-friedo-olean-20(29)-en-27,19α-lactone (welwitschiilactone A) (1), 21β-hydroxy-3,27-dioxo-30-nor-(D:A)-friedo-olean-20(29)-en-27,19α-lactone (welwitschiilactone B) (2) and 2β,21β-dihydroxy-27-oxo-30-nor-(D:A)-friedo-olean-20(29)-en-27,19α-lactone (welwitschiilactone C) (3) along with seven known compounds were isolated from the methanol extract of the roots of Caloncoba welwitschii. Their structures were determined by comprehensive spectroscopic analyses (1D and 2D NMR, EI-, ESI- and HRESI-MS). The relative configuration of the 19-oxymethine and the 21-hydroxy have been established by using the NOESY spectrum.Graphical abstract

Source: Phytochemistry Letters - July 11, 2018 Category: Chemistry Source Type: research