Tetranortriterpenoids from the Leaves of Cipadessa cinerascens

Abstract

Seven known and six new tetranortriterpenoids, cineracipadesins A-F (1-6), were isolated from the leaves of Cipadessa cinerascens. Compound 1 has a mexicanolide-type structural skeleton with a rare 9alpha,11alpha-epoxide ring; compound 2 has a methyl angolensate-type structure with 9,11-dihydroxy groups, representing the first example of a precursor of a trijugin-type limonoid; and 3 is the first reported methyl angolensate-type limonoid with a ketone group at ring C. Their structures were determined with extensive spectroscopic analysis. X-ray crystallography confirmed the structure of 1. The ability of compounds 1-7 to inhibit the growth of the P-388 murine leukemia cell line was evaluated.

Mexicanolide-Type Limonoids from the Roots of Trichilia sinensis

“…The strong IR absorptions at 3443 and 1729 cm −1 implied the presence of hydroxyl and ester carbonyl groups, respectively. The 1 H-NMR (Table 1) [7,8]. Extensive analysis of 2D NMR ( 1 H-1 H COSY and HMBC) spectra, a tigloyl moiety, an isobutyryl group, and one acetoxyl group were inferred.…”

“…Therefore, the planar structure of trichinenlide U (1) was elucidated as indicated. [7,8]. Extensive analysis of 2D NMR ( 1 H-1 H COSY and HMBC) spectra, a tigloyl moiety, an isobutyryl group, and one acetoxyl group were inferred.…”

Five new mexicanolide type limonoids from Heynea trijuga

“…The molecular formula, C 34 H 42 O 13 , and a characteristic low-field H-17 proton at δ 5.38 (1H, s) in the 1 H NMR spectrum, as well as the characteristic carbonyl group at C-1 (δ C 213.0) in the 13 C NMR spectrum, strongly suggested that 1 was a mexicanolide-type limonoid. 13,14 The 1 H and 13 C NMR data (Tables 1 and 2) of 1 including the fully substituted olefinic resonances at δ C 135.8 and 140.4 due to C-8 and C-14, respectively, were similar to those of augustineolide. 15 The major differences between them were the absence of isobutyryl group in compound 1, and the locations of the substituent.…”

“…The information above strongly suggested that 5 was a mexicanolide-type limonoid. 13,14 The key HMBC cross-peaks of Hβ-30/C-8, C-9, H-18/C-13, C-14 and H-17/C-16 revealed a conjugated vinyl-vinyl-lactone unit from C-9 to C-16. The planar structure of 5 was further confirmed by detailed 2D NMR analysis (Figure 2).…”

“…The IR spectrum showed strong absorption bands at 3432, 1762, and 1713 cm -1 , suggesting the presence of hydroxyl, and carbonyl. 1 H, 13 C, and DEPT NMR data of 5 (Tables 1 and 2) revealed a β-furan moiety, four methyl singlets, a carbomethoxy group, and a keto carbonyl at C-1 (δ C 213.0). The information above strongly suggested that 5 was a mexicanolide-type limonoid.…”