Myricitrin and bioactive extract of Albizia amara leaves: DNA protection and modulation of fertility and antioxidant-related genes expression.

Context: Albizia species are reported to exhibit many biological activities including antiovulatory properties in female rats and antispermatogenic and antiandrogenic activities in male rats.

Objective: The present study investigates the flavonoids of Albizia amara (Roxb.) B.

A flavonol triglycoside and investigation of the antioxidant and cell stimulating activities of Annona muricata Linn.

Chemical investigation on leaves of Annona muricata resulted in the isolation of the flavonol triglycoside, quercetin 3-O-α-rhamnosyl-(1″″ → 6″)-β-sophoroside, together with twelve known phenolics. The structures of these compounds were established by 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data. The in vitro antioxidant studies of the investigated aqueous ethanol extract and its column fractions were accomplished using the oxygen radical absorbance capacity (ORAC) method.

Constitutive phenolics of Harpephyllum caffrum (Anacardiaceae) and their biological effects on human keratinocytes.

Assessment of the UV protecting potential of an aqueous methanol leaf extract of Harpephyllum caffrum proved that it possesses a distinct radical scavenging effect and inhibits the production of the proinflammatory cytokine IL-6 by human keratinocytes (HaCaT cells) following UV radiation. Phytochemical investigation of this extract led to isolation and structural determination of the hitherto unknown phenolics, kaempferol 3-O-(2″-sulphatogalactopyranoside), its quercetin analogue and 3-methoxyellagic acid 4-O-galactopyranoside in addition to 18 known phenolic compounds. The structures were determined by spectroscopic and conventional methods of analysis.