Argenteanones C−E and Argenteanols B−E, Cytotoxic Cycloartanes from Aglaia argentea

Abstract

Seven new cycloartanes, argenteanones C-E (4-6) and argenteanols B-E (7-10), have been isolated from Aglaia argentea leaves. All of these compounds possess significant cytotoxic activity against KB cells (IC50 values between 3.7 and 6.2 micrograms/mL). Structure elucidation was performed by 2D NMR spectroscopy, aided by molecular modeling in the case of the side chain of compound 7.

Silvaglins and related 2,3-secodammarane derivatives – unusual types of triterpenes from Aglaia silvestris

“…by the co-occurrence of open-chained derivatives together with two types of cyclic products with tetrahydrofuran (20,24-epoxy) and tetrahydropyran (20,25-epoxy) rings (Joycharat et al, 2008b). Another type of tetrahydrofuran ring in the side-chain was reported for A. argentea Blume, where an 21,23-epoxy ring was formed in the leaves (Omobuwajo et al, 1996a;Mohamad et al, 1997), seeds (Omobuwajo et al, 1996b), and stem bark (Mohamad et al, 1999a), probably representing the precursor of the terminal furan ring typical for limonoids. A similar trend towards an 21,23-epoxy ring was also reported for the bark of A. crassinervia Kurz ex Hiern with an additional formation of a tetrahydropyran (21,24-epoxy) ring (Su et al, 2006).…”

“…In addition, various derivatives of cycloartanes (Inada et al, 1997(Inada et al, , 2001Mohamad et al, 1997;Weber et al, 2000;Joycharat et al, 2008a), tirucallanes (Benosman et al, 1995;Puripattanavong et al, 2000), apotirucallanes (Mohamad et al, 1999a), glabretals (Mulholland and Monkhe, 1993;Su et al, 2006), baccharanes (Hwang et al, 2004a,b), and lupanes (Joycharat et al, 2008a) were also reported for the genus. Recently we established a new series of stereoisomeric 3,4-secodammaranes in A. silvestris (M. Roemer) Merrill, where the tetrahydrofuran (20,24-epoxy) ring linked to the D ring was characterised by the configuration 20R.…”

Bioactive Flavaglines and Other Constituents Isolated from Aglaia perviridis

“…These characteristic NMR data suggested that 5 possesses a cycloartane skeleton, which has been reported as one of the major classes of triterpenes isolated from Aglaia species. 38,[44][45][46][47][48] In the HMBC spectrum, observed correlations from H-2, H 3 -28, and H 3 -29 to C-3, as well as H-22 to C-21 and C-17, and H-21 to C-22 supported the location of hydroxy groups at C-3 and C-22, respectively. The protons of two geminal methyls, H 3 -26 and H 3 -27, showed correlations with the Δ 24 double bond carbons, respectively.…”

“…This observation explained the different coupling pattern observed for H-3 (δ H 3.22, 1H, ddd, J = 10.4, 9.0 and 4.5 Hz), when compared with H-3 (δ H 3.28, 1H, dd, J = 10.8 and 4.4 Hz) of 3β-hydroxy cycloartane derivatives. 38,[44][45][46][47][48] The absolute configuration of C-3 was also determined as S by the Mosher ester procedure (Figure 4). A NOESY experiment revealed the consistent relative configuration of 7 with other cycloartane analogues isolated in this investigation.…”

“…Furthermore, in the NOESY spectrum, cross peaks of H 3 -28/H-19α and H-5, H-8/H 3 -18 and H-19β, as well as H-17/H 3 -30 provided evidence that the relative configurations of the remaining stereocenters of compound 5 are identical with those of previously reported related compounds. 38,[44][45][46][47][48] Hence, the structure of compound 5 was determined to be (3S,22S)-dihydroxycycloart-24-en-23-one, and this substance has been accorded the trivial name, perviridisinol A. (1H, t, J = 7.0 Hz, H-22), respectively.…”