Search

Coumarin and flavone derivatives are highly valuable molecules in drug discovery. Here, two new regioselective cross-dehydrogenation couplings of coumarins and flavones with different ethers via C(sp(3))-H functionalization processes were developed, generating new ether-substituted derivatives not previously reported. These reactions proceeded well via radical mechanisms and provided the corresponding products in good yields.

Six new acylated flavone C-glycosides, 2''-O-(2'''-methylbutyryl)isoswertisin (1), 3''-O-(2'"-methylbutyryl)isoswertisin (2), 2''-O-(2'"-methylbutyryl)vitexin (3), 2''-O-(2'"-methylbutyryl)orientin (4), 2''-O-(3'",4'"-dimethoxybenzoyl)vitexin (5), and 2''-O-(3'",4'"-dimethoxybenzoyl)orientin (6), and the known flavone C-glycoside, isoswertisin, were isolated from the flowers of Trollius ledebouri. The structures of 1-6 were elucidated by spectroscopic methods.

The New Zealand tree Quintinia acutifolia has yielded four biflavonoids, the new 2,3,2'',3''-tetrahydroochnaflavone (3), and its 7,7''-di-O-methyl derivative (1). The rare 7-O-methyl-2,3,2'',3''-tetrahydroochnaflavone (2) and 2'',3''-dihydroochnaflavone (4), both previously identified only from members of the Ochnaceae, were also isolated. Structures were determined by spectroscopic methods. This is the first report of biflavonoids from the Grossulariaceae.

Five new prenylflavonoids, artocommunols CA (1), CB (2), CC (3), CD (4), and CE (5), were isolated from the cortex of the roots of Artocarpus communis, along with the known compound cyclomorusin. The structures of 1-5 were determined by spectral methods.

High-performance liquid chromatographic methods were developed for the isolation and quantitative determination of the group B soyasaponins, including 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP)-conjugated soyasaponins alphag, betag, and betaa, and their non-DDMP counterparts, soyasaponins V, I, and II, respectively, with formononetin used as the internal standard. The limits of quantification for soy products were 0.11-4.86 micromol/g. The within-day and between-days assay coefficients of variation were9.8 and14.3%, respectively. The group B soyasaponin concentrations in 46 soybean varieties ranged from 2.50 to 5.85 micromol/g. Soy ingredients (soybean flour, toasted soy hypocotyls, soy protein isolates, textured vegetable protein, soy protein concentrates, and Novasoy) and soy foods (commercial soy milk, tofu, and tempeh) contained the group B soyasaponins from 0.20 to 114.02 micromol/g. There was no apparent correlation between isoflavone and soyasaponin concentrations in the soy products examined.

published in Advance ACS Abstracts, November 1, 1995. 0095-233819511635-1034$09.00/0 0 ing various combinations of molecular descriptors. The structures of the flavone derivatives used in this study are shown in Figure 1. A total of 34 descriptors were generated for each flavone derivative. The descriptor pool contained topological and electronic descriptors. The topological descriptors that were calculated include valence connectivity indexes6 0f”’5xv, Wiener number Wand path numbers7 pO-plo, Balaban indexs J, Harary indexes9 HI -&, and molecular topological indexi0 MTI. The electronic descriptors include hardness indexes’ ’ (absolute hardness r, relative hardness qr), energy of the highest occupied molecular orbital E(HOMO), and energy of the lowest unoccupied molecular orbital E(LUMO), topological resonance energy indices’ (topological resonance energy TRE and topological resonance energy per electron TRE(PE)), and the sum of the charges of the atoms located in the chromone moiety