Phytochemical and biological studies of Ochna species.

The genus Ochna L. (Gr, Ochne; wild pear), belonging to the Ochnaceae family, includes ca. 85 species of evergreen trees, shrubs, and shrublets, distributed in tropical Asia, Africa, and America. Several members of this genus have long been used in folk medicine for treatment of various ailments, such as asthma, dysentery, epilepsy, gastric disorders, menstrual complaints, lumbago, ulcers, as an abortifacient, and as antidote against snake bites. Up to now, ca. 111 constituents, viz. flavonoids (including bi-, tri-, and pentaflavonoids), anthranoids, triterpenes, steroids, fatty acids, and a few others have been identified in the genus. Crude extracts and isolated compounds have been found to exhibit analgesic, anti-HIV-1, anti-inflammatory, antimalarial, antimicrobial, and cytotoxic activities, lending support to the rationale behind several of its traditional uses. The present review compiles the informations concerning the traditional uses, phytochemistry, and biological activities of Ochna.

Nitrile glucosides and serotobenine from Campylospermum glaucum and Ouratea turnarea.

Two nitrile glucosides (1S,3S,4S,5R)-4-benzoyloxy-2-cyanomethylene-3,5-dihydroxycyclohexyl-1-O-beta-glucopyranoside (campyloside A) and (1S,3S,4S,5R)-5-benzoyloxy-2-cyanomethylene-3-hydroxy-4-(2-pyrrolcarboxyloxy)cyclohexyl-1-O-beta-glucopyranoside (campyloside B) were isolated from the stem roots of Campylospermum glaucum, whereas serotobenine was isolated from Ouratea turnarea. The structure elucidations were based on spectroscopic evidence. The biological assays of compounds and crude extract of plant species showed good antimicrobial activity of crude extracts against Gram-positive cocci.

Two biflavonoids from Ouratea nigroviolacea.

The leaves of Ouratea nigroviolacea (Ochnaceae) afforded two biflavonoids, ouratine A and B together with agathisflavone and stigmasterol. The biflavonoids were characterized as 4'-O-methylated apigeninyl-(I-6, II-8)-4'-O-methylatedapigenin and 4'-O-methylated apigeninyl-(I-6, II-8) apigenin by spectral and chemical transformation studies.

Antimicrobial biflavonoids from the aerial parts of Ouratea sulcata.

Investigation of the aerial parts of Ouratea sulcata led to the isolation of a biflavonoid named sulcatone A, together with the known compounds, 3-hydroxy-2,3-dihydroapigenyl-[I-4',O,II-3']-dihydrokaempferol, amentoflavone, lophirone A, agathisflavone, stigmasterol and stigmasteryl-3-O-beta-D-glucopyranoside. The structure of the compound was assigned as apigenyl-[I-4',O,II-3']-dihydrokaempferol, by means of spectroscopic analysis. Sulcatone A and 3-hydroxy-2,3-dihydroapigenyl-[I-4',O,II-3']-dihydrokaempferol exhibited significant in vitro antimicrobial activities against a range of microorganisms.

Flavonoids of Ochna afzelii.

Fractionation of the methanolic extract of Ochna afzelii stem bark has resulted in the isolation of two biflavonoids afzelones A and B along with five known flavonoids, calodenins A and B, afzelone C, 4',5-dimethoxy-6,7-methylenedioxyisoflavone, 4',5,7-trimethoxyisoflavone and the glucoside lanceoloside A. Their structures were determined using spectroscopic and chemical methods.

Two biflavonoids from Ouratea flava stem bark.

In a chemical investigation on the stem bark of Ouratea flava, two biflavonoids: 1-[3-(2,4-dihydroxy-benzoyl)-4,5,6-trihydroxy-2-(4-hydroxy-phenyl)-benzofuran-7-yl] -3-(4-hydroxy-phenyl) -propenone (flavumone A) and 3-(2,4-dihydroxy-benzoyl)-4-hydroxy-2,7-bis-(4-hydroxy-phenyl) -7,8- dihydro-furo[2,3-f]chromen-9-on (flavumone B) were isolated along with five known flavonoids. Their structures were established by various analyses including 2D-NMR spectroscopy.