Determinación de biflavonoides en diferentes partes de la especie Garcinia bakeriana (Urb) Borhidi / Determination of biflavonoids in different parts of Garcinia bakeriana (Urb) Borhidi

INTRODUCCIÓN: el género Garcinia produce una gran variedad de metabolitos secundarios representados por xantonas, acilfloroglucinoles y biflavonoides fundamentalmente. Sin embargo, existe muy poca información sobre la composición química de las especies cubanas pertenecientes a este género. OBJETIVO: determinar la presencia de 11 biflavonoides en las hojas, la corteza del tallo y el látex de Garcinia bakeriana (Urb) Borhidi. MÉTODOS : los extractos de las hojas, látex y la corteza del tallo de G. bakeriana fueron comparados empleando un método de cromatografía líquida de ultra alta eficacia (CLUAE) y 11 biflavonoides como sustancias de referencia. RESULTADOS: los biflavonoides GB-1A, GB-2A, glicósido de GB-2A, glicósido de morelloflavona, 4´´´metoxi- I3,II8-biapigenina, I3,II8-biapigenina, amentoflavona y 4´´´-metoxiamentoflavona fueron detectados como constituyentes de las hojas y la corteza del tallo de G. bakeriana. CONCLUSIONES: la especie G. bakeriana presenta biflavonoides como constituyentes de las hojas y la corteza del tallo. Además, la metodología de trabajo desarrollada contribuye al conocimiento de la composición química de la flora cubana y podría constituir una alternativa, rápida y de bajo consumo de disolventes, para el estudio comparativo de especies endémicas cubanas de escasa distribución y abundancia(AU)

INTRODUCTION: previous studies have revealed genus Garcinia to be a rich source of secondary metabolites, namely xanthones, acylphloroglucinols and bioflavonoids. However, the chemical composition of Cuban species in this genus is almost unknown. OBJECTIVE: to determine the presence of 11 biflavonoids in Garcinia bakeriana leaves, latex and stem bark. METHODS: leaves, latex and stem bark extracts of G. bakeriana were compared by using an ultra high performance liquid chromatography method (UPLC) and 11 biflavonoid standards. RESULTS: biflavonoids GB-1A, GB-2A, GB-2A glycoside, morelloflavone glycoside, 4´´´methoxy- I3,II8-biapigenin, I3,II8-biapigenin, amentoflavone y 4´´´-methoxyamentoflavone were detected as components in G. bakeriana leaves and stem bark. CONCLUSIONS: G. Bakeriana species has biflavonoids as components of its leaves and stem bark. The work methodology described in this paper helps to expand the knowledge about the chemical composition of the Cuban flora and may represent a rapid method with low dissolver consumption for the comparative study of poorly distributed and non abundant Cuban endemic species(AU)

Hypolipidemic effect of a novel biflavonoid from shells of Camellia oleifera (Abel.).

Camellia oleifera Abel. [C. oleosa (Lour.) Rehd.], an evergreen plant, is used for healthful oil production, but the shells are always discarded and need to be utilized. The present study was undertaken to explore the effect of extracts from the shells of C. oleifera on adjusting cardiovascular system. A flavonoid was obtained by reflux extraction of the shells in 70% methanol, hydrolysis in 2 M hydrochloric acid, and crystallization in acetone. Its structure was identified as a novel biflavonoid. Mice model of hyperlipidemia was setup by high fat diet for 30 d to evaluate the hypolipidemic effect of the biflavonoid at dose of 50, 100 and 200 mg/kg/d (ig). Antioxidative activity was determined by levels of malondialdehyde (MDA), superoxidase dismutase (SOD) and glutathione peroxidase (GSH-Px) in mice serum. The biflavonoid significantly controlled mice weight and liver coefficient, decreased the content of total cholesterol and triglyceride, promoted the level of high density lipoprotein in a dose dependent manner. The significant decrease of MDA content and increase of SOD and GSH-Px activity indicated it enhanced antioxidative capacity in vivo and was ascribed to hypolipidemic effect. The biflavonoid is useful in the prevention of high fat diet induced hyperlipidemia.

Trypanocidal constituents in plants: 7. Mammea-type coumarins

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 g/ml. Coumarins with a cyclized ,-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 g/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.