Structures of Sesquiterpene Polyol Esters from Celastrus stephanotiifolius with Potential Tumor-Promotion Inhibitory Activity

Abstract

Esters of eight new ([1],[4-6], and [8-11]) and five known sesquiterpenenoid polyalcohols have been isolated from Celastrus stephanotiifolius. Their structures were established on the basis of chemical reactions and spectral analysis. The structural elucidation indicated that the structures of some related compounds should be revised. The isolated sesquiterpenes were observed to inhibit Epstein-Barr virus early antigen activation significantly at low doses.

Sesquiterpene Esters from the Fruits of Celastrus orbiculatus

“…The known compounds 3, 4, and 5 were identified by comparison of their physical and spectral data with those reported in the literature. [3][4][5] Compound 1 was obtained as a white powder. The HR-MS spectrum suggested a molecular formula of C 37 H 44 O 9 for 1.…”

“…The fruits of C. orbiculatus were extracted with 95% ethanol and partitioned successively with petroleum ether, CHCl 3 , EtOAc, and n-BuOH. The petroleum ether fraction (160 g) was subjected to column chromatography on Silica gel and PHPLC to provide compounds 1-6.…”

“…In addition, the 13 C-NMR data were very similar to those assigned to 1,6,8,9-tetra-substituted b-dihydroagarofuran. 3,6) Therefore compound 1 had four ester groups linked at C-1, C-6, C-8, and C-9.…”

“…the chemical shifts and coupling pattern assignable to H-6, H-7, H-8 and H-9 in the 1 H-and 13 C-NMR spectra of 6 were very similar to those of the known compounds 6a-acetoxy-8b,9b-dibenzoyloxy-1b-hydroxy-bdihydroagarofuran, and 6a-acetoxy-1b,9b-dibenzoyloxy-8b-hydroxy-b-dihydroagarofuran reported in the literature. 3,9) The substituted group distribution in 6 was confirmed from the HMBC spectrum, which indicated cross peaks between H-6 [ 2) of benzoyloxy, respectively. Therefore one acetoxy situated at C-6 and two benzoyloxy groups and hydroxy were at C-1, C-8, and C-9, respectively.…”

Cytotoxic β-Dihydroagarofuran Sesquiterpenoids from the Fruits of Celastrus orbiculatus

“…By comparing their spectral data with those reported in the literature, compounds 1Ð9 were established to be 1 ,6α-diacetoxy-9α-benzoyloxy--dihydroagarofuran (1) (Guo et al, 2003), 1 ,6α,8 -triacetory-9α-benzoyloxy--dihydroagarofuran (2) (Guo et al, 2003), 1 -acetoxy-6α, 9α-dibenzoyloxy--dihydroagarofuran (3) (Takaishi et al, 1993), 1 ,6α,13-triacetoxy-9α-benzoyloxy--dihydroagarofuran (4) (Guo et al, 2005b), 1 , 6α-diacetoxy-8 ,9 -dibenzoyloxy--dihydroagarofuran (5) (Guo et al, 2004), 1 ,6α-diacetoxy-9 -benzoyloxy-8 -cinnamoyloxy--dihydroagarofuran (6) (Tu et al, 1991), 6α-acetoxy-1 ,8 ,9 -tribenzoyloxy--dihydroagarofuran (7) (Guo et al, 2004), 1 ,2 ,6α-triacetoxy-9α-cinnamoyloxy--dihydroagarofuran (8) (Guo et al, 2005b), 1 ,2 ,13-triacetoxy-9α-cinnamoyloxy- -dihydroagarofuran (9) (Guo et al, 2005a) (Fig. 1), respectively.…”