Revised Relative and Absolute Stereochemistry of (+)-Purpurin

Bioactive constituents of Indigofera spicata

Four new flavanones, designated as (+)-5″-deacetylpurpurin (1), (+)-5-methoxypurpurin (2), (2S)-2,3-dihydrotephroglabrin (3), and (2S)-2,3-dihydrotephroapollin C (4), together with two known flavanones (5 and 6), three known rotenoids (7-9), and one known chalcone (10) were isolated from a chloroform-soluble partition of a methanol extract from the combined flowers, fruits, leaves, and twigs of Indigofera spicata, collected in Vietnam. The compounds were obtained by bioactivity-guided isolation using the HT-29 human colon cancer, 697 human acute lymphoblastic leukemia, and Raji human Burkitt's lymphoma cell lines. The structures of 1-4 were established by extensive 1D- and 2D-NMR experiments, and the absolute configurations were determined by the measurement of specific rotations and CD spectra. The cytotoxic activities of the isolated compounds were tested against the HT-29, 697, Raji, and CCD-112CoN human normal colon cells. Also, the quinone reductase induction activities of the isolates were determined using the Hepa 1c1c7 murine hepatoma cell line. In addition, cis-(6aβ,12aβ)-hydroxyrotenone (7) was evaluated in an in vivo hollow fiber bioassay using HT-29, MCF-7 human breast cancer, and MDA-MB-435 human melanoma cells.

(+)-Apollineanin: a new flavanone from Tephrosia apollinea

Chemical investigation of the leaves of Tephrosia apollinea has yielded a new flavanone named (+)-apollineanin, together with two known flavones: (-)-semiglabrin and (-)-semiglabrinol. The structure of the new compound was determined on the basis of mass, 1D and 2D NMR spectroscopies including NOE difference spectroscopy. The absolute stereochemistry of (+)-apollineanin was determined by Mosher ester methodology and from CD data.

Furanoflavonoids: an overview

The review covers the phytochemistry and pharmacology of furanoflavonoids describing 291 compounds and containing 228 references.

Absolute configuration of novel bioactive flavonoids from Tephrosia purpurea

[structure: see text] Three novel flavonoids, (+)-tephrorins A (1) and B (2) and (+)-tephrosone (3), were isolated from Tephrosia purpurea. Their structures were elucidated by NMR spectral analysis, and their absolute configurations were determined by Mosher ester methodology. Compounds 1 and 2 are flavanones containing an unusual tetrahydrofuran moiety. Compounds 1-3 were evaluated for their potential cancer chemopreventive properties using a cell-based quinone reductase induction assay.