Tannase application in secondary enzymatic processing of inferior Tieguanyin oolong tea

Background: Inferior Tieguanyin oolong tea leaves were treated with tannase. The content and bioactivity of catechins in extracts from the treated tea leaves were investigated to assess the improvement in the quality of inferior Tieguanyin oolong tea. Results: Analysis showed that after treatment, the esterified catechin content decreased by 23.5%, whereas non-galloylated catechin and gallic acid contents increased by 15.3% and 182%, respectively. The extracts from tannase-treated tea leaves showed reduced ability to bind to BSA and decreased tea cream levels. The extracts also exhibited increased antioxidant ability to scavenge OH and DPPH radicals, increased ferric reducing power, and decreased inhibitory effects on pancreatic α-amylase and lipase activities. Conclusions: These results suggested that tannase treatment could improve the quality of inferior Tieguanyin oolong tea leaves.

Induction of secondary metabolite production by UV-C radiation in Vitis vinifera L. Öküzgözü callus cultures

BACKGROUND: The aim of the present work was to examine the role of UV-C irradiation on the production of secondary metabolites (total phenolic, total flavanols, total flavonols, catechin, ferulic acid and trans-resveratrol in phenolic compounds and α-, ß-, γ- δ-tocopherols) in callus cultures. Studies on the effects of UV-C treatment on callus culture are seldom and generally focused on UV-B. However UV-C radiation play an important role in accumule secondary metabolites. RESULTS: In this study, callus cultures from Öküzgözü grape cultivar were initiated from leaf petiole explants. Calli formed after 6 weeks on the medium supplemented with 0.5 mg L-1 benzylaminopurine (BA), 0.5 mg L-1 indole acetic acid (IAA) on B5 media. Callus tissues were exposed to UV-C irradiation at 10, 20 and 30 cm distances from the UV source for 5 and 10 minutes and samples were collected at hours 0, 24 and 48. CONCLUSIONS: The greatest total phenolic content (155.14 mg 100 g-1) was detected in calli exposed to UV-C for 5 min from 30 cm distance and sampled after 24 h. 24 h and 48 h incubation times, 30 cm and 5 min were the most appropriate combination of UV-C application in total flavanol content. Maximum total flavonol content (7.12 mg 100 g-1) was obtained on 0 h, 5 min and 20 cm combination. The highest (+)- catechin accumulation (8.89 mg g-1) was found in calli with 10 min UV-C application from 30 cm distance and sampled after 48 h. Ferulic acid content increased 6 fold in Öküzgözü callus cultures (31.37 µg g-1) compared to the control group. The greatest trans-resveratrol content (8.43 µg g-1) was detected in calli exposed to UV-C for 5 min from 30 cm distance and sampled after 24 h. The highest α-tocopherol concentration was found in calli exposed to UV-C for 10 min from 30 cm distance and sampled after 24 h. As a conclusion, it was showed that UV-C radiation had remarkable promoting effects on the accumulation of secondary metabolites in the calli of Öküzgözü grape cultivar.

Effect of chlorocholine chlorid on phenolic acids accumulation and polyphenols formation of buckwheat plants

BACKGROUND: Effect of chlorocholine chloride (CCC) on phenolic acids composition and polyphenols accumulation in various anatomical parts (stems, leaves and inflorescences) of common buckwheat (Fagopyrum esculentum Moench) in the early stages of vegetation period were surveyed. RESULTS: Treatment of buckwheat seeds with 2% of CCC has been increased content of total phenolics in the stems, leaves and inflorescences. On analyzing the different parts of buckwheat plants, 9 different phenolic acids - vanilic acid, ferulic acid, trans-ferulic acid, chlorogenic acid, salycilic acid, cinamic acid, p-coumaric acid, p-anisic acid, methoxycinamic acid and catechins were identified. The levels of identified phenolic acids varied not only significantly among the plant organs but also between early stages of vegetation period. Same changes as in contents of chlorogenic acid, ferulic acid, trans-ferulic acid were found for content of salycilic acid. The content of these phenolic acids has been significant increased under effect of 2% CCC treatment at the phase I (formation of buds) in the stems and at the phase II (beginning of flowering) in the leaves and then inflorescences respectively. The content of catechins as potential buckwheat antioxidants has been increased at the early stages of vegetation period after treatment with 2% CCC. CONCLUSIONS: The obtained results suggest that influence of CCC on the phenolics composition can be a result of various mechanisms of CCC uptake, transforming and/or its translocation in the buckwheat seedlings.

Validación de la técnica para la determinación de catequina en tabletas de Rhizophora mangle L por CLAR / Validation of the technique to assessment of tablets Catechin from Rhizophora mangle L by HPLC

Se realizó la validación del método de cromatografía líquida de alta resolución para la determinación cuantitativa de catequina como sustancia marcador en las tabletas obtenidas a partir del extracto seco de las cortezas de Rhizophora mangle L, empleadas en el tratamiento de úlceras gastroduodenales. Considerando que el método se clasifica como tal para la determinación cuantitativa del compuesto mayoritario o ingrediente activo en formulaciones o materia prima, se evaluaron los parámetros: especificidad, linealidad, exactitud, sensibilidad y precisión expresada en sus 2 formas: repetibilidad y precisión intermedia. Los resultados obtenidos demostraron que el método empleado es confiable, pues permitió la determinación del compuesto en presencia de otras sustancias, incluyendo excipientes y sustancias auxiliares, y detectó la presencia de productos de degradación. Además, el procesamiento estadístico de los resultados evidenció la linealidad, precisión, sensibilidad y exactitud del método.

Authors made the high-performance liquid chromatography method validation to the quantitative assessment of cathechin as a marker substance in tablets obtained from the bark of Rhizophora mangle L dry extract used in gastroduodenal ulcers treatment. Considering that this method as such is classified to quantitative assessment of the major compound or active ingredient in formulae or raw material, the following parameters were assessed : linearity, accuracy, sensitivity and precision expressed in its two ways: repetition and intermediate precision. Results obtained showed that this method is reliable allowing the compound assessment in presence of other substances, including excipients and auxilliary substances and to detect the presence of degradation products. Also, the statistical processing of results evidenced the linearity, precision, sensitivity and accuracy of this method.

Evoluçäo dos fenólicos totais e taninos condensados (Proantocianidinas) durante o desenvolvimento das sementes do feijäo (Phaseolus vulgaris L.) / Evolution of phenolic compounds and condensed tannins (Proanthocyanidins) during the development of bean seeds (Phaseolus vulgaris L.)

The evolution of phenolic compounds and tannins (proanthocyanidins) of bean seeds, Phaseolus vulgaris L., (cultivar aroana 80), from anthesis to maturity (10 to 45 days after anthesis), was investigated. During seed development, phenolic compounds and tannins contents increased by seed unit, until the 31st and 21st day after anthesis respectively, decreasing afterwards. The gradual decrease in catechin and the increase of its polymers (intermediate compounds), as well as the gradual increase in alpha-amylase inhibition capacity were indications that tannins polymerize during seed development