[Study on the UV-quantitative analysis of theabrownins in Pu-Erh tea].

An UV-quantitative analysis method for the theabrownin (TB) in Pu-erh tea and its derived products was established in the present study. The results showed that the Pu-erh tea shows characteristic absorption at the wavelength of 270 nm, which can be used as wavelength for the content determination of TB. The preparation methods of standard TB and standard curve were also established. The determination results show that the method is simple, the results have certain credibility, and the established method can be used for the determination of TB in Pu-erh tea and its derived products.

Influence of different fermentation raw materials on pyrolyzates of Pu-erh tea theabrownin by Curie-point pyrolysis-gas chromatography-mass spectroscopy.

SCOPE: In this study, Pu-erh tea was prepared by solid-state fermentation of the sun-dried green tea, short-fermentation black tea, and black tea. Ultraviolet-visible spectroscopy, infrared spectroscopy and Curie-point pyrolysis-gas chromatography-mass spectroscopy (CP-Py-GC/MS) were used to study the characteristics and chemical compositions of the TB formed in these Pu-erh teas. METHODS AND RESULTS: The pyrolysates of the Pu-erh teas' theabrownin (TB1, TB2, TB3) were analyzed at 386°C using a Curie point pyrolysis instrument. TB1, TB2, and TB3 produced 158, 135 and 148 pyrolysis products, respectively. These compounds could be grouped as follows: alkaloids, 25.23% (TB1), 25.67% (TB2), and 21.91% (TB3); phenols, 24.19% (TB1), 23.08% (TB2), and 29.91% (TB3); nitrogen-compounds, 11.79% (TB1), 11.25% (TB2), and 13.39% (TB3); hydrocarbons, 10.96% (TB1), 10.37% (TB2), and 11.37% (TB3); ketones, 10.34% (TB1), 6.58% (TB2), and 8.22% (TB3); furan, 5.40% (TB1), 4.06% (TB2), and 2.33% (TB3); alcohol, 3.30% (TB1), 4.16% (TB2), and 3.34% (TB3); fatty acids, 2.80% (TB1), 4.03% (TB2), and 1.42% (TB3); esters 2.17% (TB1), 0.99% (TB2) and 2.35% (TB3); and amines 1.61% (TB1), 2.81% (TB2), and 0.86% (TB3). CONCLUSION: Theabrownin mainly contains alkaloids (caffeine), tea pigments, polysaccharides, proteins and lipids. Its precursors include various polyphenols, tea pigments, alkaloids, polysaccharides, proteins and lipids. These compounds in the raw materials impact the chemical composition of theabrownin, and black tea is not a suitable raw fermentation material for Pu-erh tea.

[Protective effects of total alkaloids from rhizoma Coptis chinensis on alcohol-induced gastric lesion in rats].

OBJECTIVE: To study the effects of total alkaloids(TA) from rhizoma Coptis chinensis on alcohol-induced gastric lesion in rats and the possible mechanisms. METHOD: The experimental gastric damges were established by intragastric(ig) absolute ethanol, and possible protective effects of TA given orally previously were evaluated by following parameters: gastric damage indexes, gastric juice volume, acidity, and mucus quantity. The contents of NO, MDA, *OH, and SOD activity were also measured in gastric mucosa. RESULT: TA showed significantly inhibitive effects on gastric damages induced by ig ethanol in a dose dependent manner. The effects of TA (120 mg x kg(-1)) were stronger than that of both cimitidine(70 mg x kg(-1)) and berberine(100 mg x kg(-1)), the quantity of later was equal to TA as calculated with berberine. TA significantly suppressed secretion of gastric acid caused by ethanol without clear influences on gastric juice volume and mucus secretion. TA obviously blunted ethanol-induced elevation of MDA and *OH, as well as decrease of NO level and SOD activity from gastric mucosa. CONCLUSION: It is suggested that the TA is a potent protective agent against ethanol-induced gastric damages. The mechanism of actions may be related with inhibiting the secretion of gastric acid and blunting the increase of MDA and *OH, as well as the decrease of NO level and SOD activity from gastric mucus.