A new diaryl 1, 2-diketone from the heartwood of Dalbergia latifolia

Two new compounds from the heartwood of Dalbergia melanoxylon

A new neoflavonoid, named S(+)-3'-hydroxy-4',2,4,5-tetramethoxydalbergiquinol (1), and a new benzofuran, named (2S,3S)-5-hydroxy-6-methoxy-3-methyl-2-(4'-hydroxyphenyl)-2,3dihydrobenzofuran (4), together with two known neoflavonoids, were isolated from the heartwood of Dalbergia melanoxylon. Their structures were elucidated by a combination of spectroscopic methods and comparison with the literature. Compounds 1-4 were evaluated for inhibitory activity against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 6538, Salmonella enteri CMCC 50041 and Candida albicans ATCC 289065, which all exhibited inactive or weak activity.

Rotenoid and isoflavone metabolites from an antioxidant seed extract of Dalbergia lanceolaria subsp. paniculata (roxb.) thoth

A new rotenoid named 12-O-methylrotenolol along with five known rotenoid and isoflavone metabolites were isolated from the seeds of Dalbergia lanceolaria subsp. paniculata, collected from Egypt. The structures of these compounds were identified by physical and spectroscopic data measurements ([α]_D, UV, 1D- and 2D-NMR and MS). The methanol extract of the seeds exhibited strong antioxidant activity with IC₅₀ value 0.7 µg/µl against DPPH radical, in respect to quercetin as antioxidant reference (IC₅₀ 1.5 μM), while the tested compounds from this extract showed weak activities with IC₅₀ values ranged from 19.6 to 33.0 µM.