guajavarin and quercitrin

To investigate the chemical constituents of Psidium guajava L, the EtOH/H(2)O extract of the fresh leaves was subjected to various chromatography. One diphenylmethane, one benzophenone, and eight flavonoids were isolated and elucidated as 2,6-dihydroxy-3-formaldehyde-5-methyl-4-O-(6″-O-galloyl-β-D-glucopyranosyl)-diphenylmethane (1), 2,6-dihydroxy-3,5-dimethyl-4-O-(6″-O-galloyl-β-D-glucopyranosyl)-benzophenone (2), kaempferol (3), quercetin (4), quercitrin (5), isoquercitrin (6), guaijaverin (7), avicularin (8), hyperoside (9), reynoutrin (10) by spectroscopic methods, including 1D and 2D NMR and HR-ESI-MS spectrometry as well as by comparison with published data. Compounds 5 and 10 are obtained from P. guajava for the first time, and compound 1 is a new diphenylmethane compound.

Topics: Benzhydryl Compounds; Benzophenones; Flavonoids; Gallic Acid; Glucosides; Glycosides; Magnetic Resonance Spectroscopy; Molecular Structure; Plant Leaves; Psidium; Quercetin; Spectrometry, Mass, Electrospray Ionization

A new acylated avicularin, namely avicularin 2''-(4'''-O-n-pentanoyl)-gallate (1) along with 12 metabolites have been isolated from the ethyl acetate extract of the aerial parts of Jussiaea repens L. (Onagraceae). Their structures were established as trifolin 2''-O-gallate (2), quercetrin (3), guaijaverin (4), reynoutrin (5), juglanin (6), avicularin (7), hyperin (8), trifolin (9), hyperin 2''-O-gallate (10), rutin (11), kaempferol (12) and quercetin (13) on the basis of their chromatographic properties, chemical and spectroscopic evidences. The investigated ethyl acetate extract was found to be non-toxic (LD(50) up to the maximum soluble dose 4 g kg(-1) body wt.) and had significant antioxidant, hepatoprotective, anti-inflammatory and antidiabetic activities. Also some of the isolated flavonoids showed cytotoxic activity against Ehrlich ascitis carcinoma cells.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Flavonoids; Galactosides; Hypoglycemic Agents; Kaempferols; Magnetic Resonance Spectroscopy; Male; Mice; Molecular Structure; Onagraceae; Plant Extracts; Quercetin; Rats

To further investigate the flavonoids of Rhododendron anthopogonoide.. The compounds were isolated and purified by Sephadex LH-20, polyamide and silica gel column chromatography. Their chemical structures were elucidated on the basis of physicochemical properties and spectral data.. Six compounds were isolated and identified as: taxifolin (I), guaijaverin (II), reynoutrin (III), quercitrin (IV), polystachoside (V) and quercetin-4'-O-beta-D-galactoside (VI).. For the first time, compound VI was separated from Ericaceae plant, compounds II and V were isolated from Rhododendron plant, and compounds I and II were obtained from this plant.

Topics: Flavonoids; Flavonols; Galactosides; Plant Leaves; Plant Stems; Plants, Medicinal; Quercetin; Rhododendron

The traditional herbal remedy from Psidium guajava leaves has been medically proposed in Mexico as effective treatment of acute diarrhea. A methanolic leaf extract was subjected to a bioassay-guided isolation of spasmolytic constituents. Six fractions were separated on a polyvinylpolypyrrolidine (PVPP) column using a water methanol-gradient. The fraction containing flavonols inhibited peristalsis of guinea pig ileum in vitro. A trace of quercetin aglycone together with five glycosides was isolated from this active fraction and identified as quercetin 3-O-alpha-L-arabinoside (guajavarin); quercetin 3-O-beta-D-glucoside (isoquercetin); quercetin 3-O-beta-D-galactoside (hyperin); quercetin 3-O-beta-L-rhamnoside (quercitrin) and quercetin 3-O-gentobioside. Biological activity of each pure compound was studied in the same bioassay. Obtained results suggest that the spasmolytic activity of the Psidium guajava leaf remedy is mainly due to the aglycone quercetin, present in the leaf and in the extract mainly in the form of five flavonols, and whose effect is produced when these products are hydrolyzed by gastrointestinal fluid.

Topics: Animals; Antidiarrheals; Drug Evaluation, Preclinical; Gastric Acid; Glycosides; Guinea Pigs; Hydrolysis; Ileum; Male; Methanol; Mexico; Muscle Relaxation; Muscle, Smooth; Parasympatholytics; Plant Extracts; Plants, Medicinal; Quercetin