Two Cangorosin A Type Triterpene Dimers from Maytenus chuchuhuasca

Abstract

Two new cangorosin A type triterpene dimers, which composed of two triterpene units jointed by two ether linkages between the A and B rings, were isolated from the Brazilian medicinal plant "xuxuá" (Maytenus chuchuhuasca). Structures of new isolates, xuxuasins A (1) and B (2), were established based on several spectroscopic evidences.

Cytotoxic Triterpenoids from Maytenus retusa

“…5 The main difference was the absence of Me-23. The HMBC correlations spectrum (Figure 3) together with the 13 C NMR and DEPT data (Table 2) agreed with 6 being 23-nor-blepharodol.…”

“…The 1 H NMR, 13 C NMR, and DEPT spectra revealed that 7 was a sesquiterpenetriterpene adduct. 18,43 Its 1 H NMR spectrum presented signals characteristic of a triterpenic unit related to the isotingenol series: 49 five methyl groups, one doublet methyl (δ 1.00, J ) 5.9 Hz), two vinylic protons at δ 6.67 (1H, dd, J ) 9.8, 2.…”

“…The shift of H-1 was similar to that in macrocarpin C, 41 which has a carboxylic acid at C-4. We could not obtain the 13 C NMR spectrum of this compound since it decomposed rapidly. Thus, the proposed structure for compound 5 is 6-oxo-7,8-dihydropristimerol-23-oic acid.…”

“…Maytenus species constitute a rich source of terpenoids such as friedelane-type triterpenes (quinonemethide, enequinone-methide, andphenolictypes), [5][6][7] lupanes, 8 oleananes, 9,10 dimerictriterpenes, [11][12][13] diterpenes such as kaurane and abietane, [14][15][16] sesquiterpenes, 17 and sesquiterpene-triterpene hetero-Diels-Alder adducts. 18 The aromatic and quinoid triterpenes are of interest due to their antibiotic and cytotoxic activities.…”

“…In this paper we describe the isolation and structural elucidation of seven new terpenes (1-7) and 36 known terpenoids. The structures of the isolated compounds were determined by spectroscopic studies ( 1 H NMR and 13 C NMR), including bidimensional homonuclear (COSY and ROESY) and heteronuclear (HSQC and HMBC) correlation experiments. Some of the compounds showed cytotoxic activity against the human tumor cell lines HL-60 and MCF-7.…”