New flavonoid C–O–C dimers and other chemical constituents from Garcinia brevipedicellata stem heartwood

Abstract

The methanol extract of the stem heartwood of Garcinia brevipedicellata has furnished three new flavonoid C-O-C dimers, brevipedicilones A (6), B (8) and C (10), along with five previously reported flavonoid dimers, viz. amentoflavone (1), 4″'-O-methylamentoflavone (2), robustaflavone (3), 4'-O-methyl robustaflavone (4) and tetrahinokiflavone (5). The new structures, which are composed of flavanone-flavanonol or flavanonol-flavanonol sub-units, were established based on spectroscopic analysis including 1D and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY) spectroscopy, and by comparing their spectral data with those reported for related compounds.

Antiproliferative Activity and Antioxidant Potential of Extracts of Garcinia gardneriana

“…The determination of the chemical profiles of FEE (fruit ethanolic extract), EEFH (hexane fraction), EEFC (chloroform fraction), EEFA (ethyl acetate fraction), EEFW (hydromethanolic fraction), EEL (ethanol leaf extract), EELH (hexane fraction), EELC (chloroform fraction), EELA (ethyl acetate fraction), and EELW (hydromethanolic fraction) were performed based on UV, MS, and MS/MS data as compared with data described in the literature [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Twenty-six compounds were tentatively identified ( Table 1 and Table 2 , Figure 1 ).…”

From Tea to Health: Exploring Abrus mollis for Liver Protection and Unraveling Its Potential Mechanisms

“…Compound 3 was isolated as a yellow powder and its molecular formula was deduced as C 15 H 14 O 4 on the basis of its (+)-HR-ESI-MS data (m/z 257.0830 [M − H] − , calcd for 257.0814). The 1 H NMR data (Table 1) of 3 showed the hydrogen signal of the ABX coupling system on the benzene ring [δ H 7.84 (1H, d, J = 8.9 Hz, H-6'), 6.34 (1H, dd, J = 8.9, 2.2 Hz, H-3′), and 6. with that of (2S, 2″S) tetrahydronokiflavone, 36 it was found that the plane structures of the two compounds were almost similar except the substitution position of the methoxy. The HMBC correlation from δ H 3.78 (3‴-OCH 3 ) to δ C 148.0 (C-3‴) suggested that the methoxy was attached to C-3‴.…”

chemical constituents from methanolic extract of Garcinia mackeaniana leaves and their antioxidant activity

“…In comparison with literature data, isolated compound 4 was determined to be a biflavone, which was trivially named amentoflavone [16]. Secondary metabolite 4 has ever been isolated from various Garcinia species, such as G. brevipedicellata stem heartwoods, or G. livingstonei leaves, however, it was now found in G. mackeaniana [17,18] for the first time. [19], compound 5 was unambiguously determined to be methyl 3,4dihydroxybenzoate, which was trivially named methyl protocatechuate.…”