Cytotoxic C-benzylated flavonoids from Uvaria chamae

Abstract

in methanol for 24 h. The filtrate and washes were evaporated to dryness: yield 77 mg, 36% by weight; 127 wmol Val, 7.7 pmol Gly (yield 32%). Total 14C counts recovered in the filtrate indicated a yield of 36%. The solid was recrystallized from ether-petroleum ether. Paper electrophoresis at pH 1.5 gave a single radioactive spot at Rval 0.48 (standards of Gly-Val, Asp, and cyclic Dca-Val appeared at 0.86,0.74, and 0.66, respectively); 'H NMR (Varian HF, 220 MHz, MezSO-de) 6 0.91 (m, 6 H), 1.3-1.4 (broad m, cyclohexyl axial), 1.6-1.8 (broad m, cyclohexyl equatorial), 2.06 (m, 1 H, Val p-CH), 3.1 (m, tertiary CH), 4.1-4.2 (m,3 H, a-CH), 3.8 (~,3H,OCH3),7.32 (d,2H, J=8Hz,cyclohexyl NH), 7.68 (t, 1 H, J = 7 Hz, Gly NH), 8.64 (d, 1 H, J =: 8 Hz, Val XH); I3C NMR (Bruker HX-90, 22.6 MHz, proton decoupled,

Cytotoxic C-Benzylated Dihydrochalcones from Uvaria acuminata

“…Thus compound 1 is a 2Ј-hydroxydihydrochalcone. Further, the 1 H-and 13 C-NMR spectral data of 1 (Tables 1, 2) were very similar to those of diuvaretin (6), except that a methoxyl signal was absent from 1. The 1 H-NMR spectrum showed two sets of signals due to a 2-hydroxybenzyl group, which were found to be attached to the 3Ј and 5Ј of ring A of dihydrochalcone skeleton on the basis of the heteronuclear multiple-bond connectivity (HMBC) spectrum (Fig.…”

“…Hence the possibility of the structure 2a was excluded. Consequently, the new compound 10) uvaretin (4), 3,6,11) isouvaretin (5), 6,11) diuvaretin (6), 6,11) and uvangoletin (7), 12) respectively, by comparing these spectral data with values reported in the literature. Compounds 3, 5, 6, and 7 were isolated for the first time from U. acuminata.…”

“…We therefore tried to obtain the compounds by a combination of column chromatography and preparative HPLC, and isolated two new C-benzylated dihydrochalcones called isochamuvaritin (1) and acumitin (2), along with benzylbenzoate (3), uvaretin (4), isouvaretin (5), diuvaretin (6), and uvangoletin (7). This paper deals with the structural elucidation of the two new C-benzylated dihydrochalcones isolated from the root of U. acuminata.…”

“…Furthermore, we investigated the cytotoxic activities of the isolated dihydrochalcones against HL-60 cells, paying special attention to the cytotoxicity of the new compounds, since it was reported that dihydrochalcons of Uvaria like uvaretin, isouvaretin, and diuvaretin have cytotoxic activities against both PS and KB cell cultures. 6) The petroleum ether extract of the root of U. acuminata was separated by a combination of chromatographic procedures to yield seven compounds. The first new compound (1) was obtained as white crystals from CHCl 3 /Me 2 CO, mp 157-159°C, and had a molecular formula of C 29 H 24 O 5 based on high resolution electron impact mass spectrum (HR-EI-MS).…”

Induction of Apoptosis in Human Promyelocytic Leukemia Cell Line HL-60 by C-Benzylated Dihydrochalcones, Uvaretin, Isouvaretin and Diuvaretin

“…Uvaretin (1), isouvaretin (2) and diuvaretin (3) are known as C-benzylated dihydrochalcones peculiar to the genus Uvaria in the Annonaceae (Fig. 1).…”