Beta-D-glucosidase-catalyzed deglucosidation of phenylpropanoid amides of 5-hydroxytryptamine glucoside in safflower seed extracts optimized by response surface methodology.

Beta-D-glucosidase-catalyzed deglucosidation of phenylpropanoid amides of 5-hydroxytryptamine (PAHAs) glucoside in safflower (Carthamus tinctorius L.) seed extracts, including N-(p-coumaroyl)serotonin glucoside (CSG) and N-feruloylserotonin glucoside (FSG), was optimized by response surface methodology (RSM). The Box-Behken design (BBD) was employed to evaluate the interactive effects of independent variables on the deglucosidation rates of CSG and FSG. The variables involved were pH (5.6-6.2), temperature (45-55 degrees C), and enzyme load (2.0-3.0%, relative to the weight of the total substrate). The substrate concentration was fixed at 3.3 g/L on the basis of factorial experiments. The optimum conditions obtained via RSM at a fixed time of 2 h were as follows: pH, 5.9; temperature, 48 degrees C; and enzyme load, 3.0%. Under these conditions, the actual deglucosidation rates of CSG and FSG were 75.5 and 42.2%, respectively, which agree well with the predicted values (75.3 and 41.9%) by RSM. The final incubation time (10 h) was determined by the time course of the deglucosidation under the above-mentioned optimum conditions, which gave the deglucosidation rates of both CSG and FSG above 90%. Simultaneously, 2-hydroxyarctiin, a typical cathartic beta-glucoside, was also removed by 80.3%.

Antioxidant and protective effect of an oleanolic acid-enriched extract of A. deliciosa root on carbon tetrachloride induced rat liver injury.

The ethanol-water extract of A. deliciosa root (EEAD) was fractionated into n-hexane (EEAD-He), ethyl acetate (EEAD-Ea), n-butanol (EEAD-Bu) and aqueous (EEAD-Aq) fractions according to their different polarity and solubility. Among the four extracts, it was found that EEAD-Bu was enriched with oleanolic acid (OLA). The antioxidant and hepatoprotective activities of various EEAD fractions and OLA were carefully investigated by the methods of ferric thiocyanate (FTC) and thiobarbituric acid (TBA), as well as the model of CCL4-induced liver toxicity in rats. The results showed that the EEAD-Bu had higher in vitro antioxidant and in vivo hepatoprotective activities than those of the other types of extracts (p< 0.05). When the CCL4-induced rats were treatment with 120 mg/kg EEAD-Bu, the activities of alanine transaminase (ALT) and aspartate transanimase (AST) in rat serum decreased 90 % and 81 %, respectively, as compared with those of the CCL4 control rats. Furthermore, the lipid peroxidation (MDA) decreased 42 % and glutathione (GSH) increased 114 % in the rats liver homogenate, as compared with those of the control. The results also indicated that the hepatoprotective activity of the EEAD-Bu (at the dose of 120 mg/kg) was higher than that of the reference drug silymarin (at the dose of 60 mg/kg), and OLA acted as an important role in dose-dependent protection against CCL4 hepatotoxicity. The findings indicate that the OLA-enriched EEAD-Bu extract had significant and concentration dependent hepatoprotective effect for the carbon tetrachloride induced rat liver injury.

Detection of free radical transfer in lipoxygenase I-B-catalyzed linoleic acid-soybean protein interaction by electron spin resonance spectroscopy (ESR).

Effects of lipoxygenase I-B (LOX)-catalyzed oxidation of linoleic acid on soybean proteins was evaluated by electron spin resonance (ESR) and fluorescence spectroscopy in different model systems in the presence or absence of antioxidants. A strong central singlet signal was detected by ESR spectroscopy and identified as the carbon radical (g value range 2.0041-2.0054). A downfield shoulder attributed to the sulfur radical (g value 2.019-2.028) was also observed. The changes in soybean proteins were accompanied by an increase in fluorescence, indicating the formation of cross-links. Natural antioxidants such as ascorbic acid and alpha-tocopherol as well as synthetic antioxidants butyl hydroxytoluene (BHT) inhibited the development of both the free radical signal and the fluorescence when added to soybean proteins prior to incubation with linoleic acid and lipoxygenase I-B; the central singlet signal attributed to the carbon radical was reduced by 35-65%. This paper clearly indicates direct free radical transfer from oxidizing linoleic acid catalyzed by LOX to soybean proteins.

[Separation and purification of the main glucosinolate from rapeseeds].

A procedure for the preparative isolation of 1-S-[(1Z)-3-hydroxy-1-[(sulfooxy) imino]-4-pentenyl]-1-thio-beta-D-glucopyanose, potassium salt (progoitrin) from Brassica oleracea is reported. The major steps in this procedure were: (1) extraction of glucosinolates with methanol from Brassica oleracea; (2) separation and purification of glucosinolates by chromatographic column on alumina support; and (3) a follow-up reversed-phase separation by octadecyl (C18) silica support yielding progoitrin as the main content of glucosinolate. The structure of progoitrin was identified on its physicochemical properties by ultraviolet absorption spectrometry, infrared absorption, 'H nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. Spectroscopic data of the sample isolated were in agreement with those reported in the literature. The purity of progoitrin obtained was determined to be 99% by high performance liquid chromatography. The simplicity of the separation and purification procedure for glucosinolates and the high purity of progoitrin isolated would make the method an important reference for future research on glucosinolates and a favorable technique for future development.

[Study on technique of extraction and purifying chlorogenic acid in Eucommia ulmoides Oliver leaves].

Ethanol was used as solvent to extract chlorogenic acid from leaves of Eucommia ulmoides Oliver leaves. The optimum conditions are obtained by response surface analytical method. Optimized conditions for the extraction of chlorogenic acid were obtained: ethanol 51.7%, extraction temperature 55.8 degrees C, ratio of material to liquor 1:12.8, extraction time 2 h. The static adsorption tests are conducted among six kinds of macroporous resins to select NKA-II resin as a optimum resin to adsorb the chlorogenic acid in Eucommia ulmoides Oliver leaves. The optimum adsortion-elution conditions are as follow: adsorption flow rate is 2 ml/min, crude liquid flew twice through the adsorption column,the optimum adsorbent is 40% ethanol.