The objective of the study was to optimize the processing of Microwave-Assisted Extraction (MAE) of flavonoids from Cryptotaenia japonica Hassk. The effects of processing parameters include ethanol proportion, extraction time, extraction temperature and ratio of liquid to solid on the flavonoids yield were determined and the optimal conditions for flavonoids were evaluated by means of Response ...

Two parasitic and achlorophyllous species, Aeginetia indica and Orobanche minor belonging to the family Orobanchaceae, were surveyed for flavonoids. The flowers and aerial parts of A. indica were exracted with MeOH and the flavonoids were isolated by various chromatographical techniques. Two anthocyanins were obtained from the flowers together with other flavonoids, and characterized as cyanidi...

For the purpose of the development of a skin-whitening agent, Sophora flavescens was evaluated for tyrosinase inhibitory activity and its active principles were identified following activity-guided isolation. The ethanol extract and dichloromethane fraction from S. flavescens showed significant inhibition of mushroom tyrosinase. From the dichloromethane fraction, three known prenylated flavonoi...

A new furanoisoflavone, 2'-methoxy-4',5'-methylenedioxy-[2'',3'':7,8] furanoisoflavone, leptobotryanone (1), and a new natural O-prenylated isoflavone, 4'-γ,γ-dimethylallyloxy-5,7-dihydroxyisoflavone (2), were isolated from the twigs of Millettia leptobotrya, together with twelve known flavonoids, 4'-γ,γdimethylallyloxy-5-hydroxy-7-methoxyisoflavone (3), 2',6,7-trimethoxy-4',5'-methylenedioxyis...

María Clavin1, Silvia Cazorla2,3, Renata Spina4, Miguel A. Sosa4, Emilio Malchiodi2, Virginia Martino1, Fernanda Frank2,3,†, Liliana Muschietti1,†,* 1Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Farmacognosia. IQUIMEFA (UBACONICET), Junín 956 2° F (1113), Buenos Aires, Argentina. 2Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Inmunologí...

The seeds of Indigofera heterantha yielded a flavonoid characterized as quercetin 3-O-α-L-rhamnoside along with known 3,5,7-trihydroxy-6,4 ́-dimethoxyflavone and 3,5,4 ́-trihydroxy-6,7-dimethoxyflavone. The isolated compounds were characterized by using modern spectroscopic techniques such as UV, IR, NMR and mass.

That flavonoids inhibit xanthine oxidase from cow milk was confirmed by measuring oxygen consumption with an oxygen electrode. In contrast, flavonoids did not inhibit glucose oxidase, another oxygen consuming enzyme. Among the flavonoids tested, quercetin, kaempferol, myricetin, chrysin, quercitrin, and morin were potent inhibitors of xanthine oxidase; their inhibition rates (%) were 80, 70, 69...

Plant flavonoids represent an important group of secondary metabolites and around 6500 varieties of flavonoids have been reported so far. These are the polyphenolic compounds that are found in almost all plant species. Extensive biological roles of flavonoids have been reported which include antiviral, anti-hepatotoxic, therapeutic, antibacterial, and other roles in nature. The presence of flav...

Stress-responsive dihydroxy B-ring-substituted flavonoids have great potential to inhibit the generation of reactive oxygen species (ROS) and reduce the levels of ROS once they are formed, i.e., to perform antioxidant functions. These flavonoids are located within or in the proximity of centers of ROS generation in severely stressed plants. Efficient mechanisms have been recently identified for...