kaempferol-3-o-rhamnoside and lespenefril

Biological activities of flavonoids have been extensively reviewed in literature. The biochemical profile of afzelin, kaempferitrin, and pterogynoside acting on reactive oxygen species was investigated in this paper. The flavonoids were able to act as scavengers of the superoxide anion, hypochlorous acid and taurine chloramine. Although flavonoids are naturally occurring substances in plants which antioxidant activities have been widely advertised as beneficial, afzelin, kaempferitrin, and pterogynoside were able to promote cytotoxic effect. In red blood cells this toxicity was enhanced, depending on flavonoids concentration, in the presence of hypochlorous acid, but reduced in the presence of 2,2'-azo-bis(2-amidinopropane) free radical. These flavonoids had also promoted the death of neutrophils, which was exacerbated when the oxidative burst was initiated by phorbol miristate acetate. Therefore, despite their well-known scavenging action toward free radicals and oxidants, these compounds could be very harmful to living organisms through their action over erythrocytes and neutrophils.

Topics: Animals; Cell Death; Erythrocytes; Fabaceae; Flavonols; Free Radical Scavengers; Hemolysis; Humans; Hypochlorous Acid; In Vitro Techniques; Kaempferols; Mannosides; Neutrophils; Oxidative Stress; Proanthocyanidins; Rats; Reactive Oxygen Species; Respiratory Burst; Superoxides; Taurine; Tetradecanoylphorbol Acetate

The tyrosinase inhibitory activity of ethanolic extract of kenaf (Hibiscus cannabinus L.) leaf was evaluated before and after subjecting it to far-infrared (FIR) irradiation. The main component of the extract was analyzed as kaempferitrin (kaempferol-3,7-O-α-dirhamnoside). Prior to FIR irradiation, no inhibitory activity of the extract was detected in a tyrosinase assay. However, after FIR irradiation for 1h at 60°C, significant tyrosinase inhibitory activity (IC(50)=3500 ppm) was observed in it. In HPLC analysis, derhamnosylation products (kaempferol, afzelin, and α-rhamnoisorobin) were detected. The inhibitory activity may be due to the existence of derhamnosylation products. This study demonstrated that FIR irradiation can be used as a convenient tool for deglycosylation of flavonoid glycoside.

Topics: Flavonoids; Hibiscus; Infrared Rays; Kaempferols; Mannosides; Monophenol Monooxygenase; Plant Extracts; Plant Leaves; Proanthocyanidins

To study the biotransformation of kaempferitrin, a major chemical principle of the fruits of Siraitia grosvenori (Swingle) C. Jeffery, with human intestinal flora.. The kaempferitrin was incubated with human intestinal flora. The biotransformation products were isolated and purified by chromatographic methods and the structures were determined by spectroscopic techniques.. Kaempferitrin was converted into kaempferol 3-O-alpha-L-rhamnoside (afzelin, I) , kaempferol 7-O-alpha-L-rhamnoside (II), kaempferol (III) and p-hydroxybenzoic acid (IV) by human intestinal flora. rhamnoside (II), kaempferol (III) and p-hydroxybenzoic acid (IV) by human intestinal flora.. The structure of kaempferitrin can be biotransformatedly converted by human intestinal flora.

Topics: Bacteria; Biotransformation; Fruit; Humans; Intestines; Kaempferols; Mannosides; Momordica; Parabens; Plants, Medicinal; Proanthocyanidins