1.A Novel Biocatalyst and Its Optimized Process for Preparing L-theanine
Jiayou LI ; Liyun GUO ; Qingcai JIAO
China Biotechnology 2007;27(10):34-38
L-theanine (γ-glutamylethylamide) is the main free amino acid component of tea and its favorable physiological effects on mammals have been reported. An enzymatic method for optically pure L-theanine production with a new L-aminoacylases-production fungi Cunnighamella echinulata 9980 was developed. The optimum conditions for enzymatic catalysis were at pH 6.5 with 50 mmol/L N-Acyl-DLtheanine and 40 mmol/L CoCl2. After 12-h incubation at 50℃,22.5 mmol/L L-theanine was obtained, the conversion rate against N-Acyl-L-theanine being 90%. Cunnighamella echinulata and the aminoacylase were applied in preparation of L-theanine.
2.Hypocrellins produced by anamorphosis fermentation of Shiraia bambusicola
Jiajia CHEN ; Zhaolan LI ; Qingcai JIAO
Chinese Traditional and Herbal Drugs 1994;0(01):-
Objective To obtain anamorphosis of Shiraia bambusicola producing the component,hypocrellin A effectively.Methods A strain was isolated from the fruit of S.bambusicola by separating its hypha and was cultured by solid-state fermentation.One of the pure chemical compounds isolated from the stroma of wild S.bambusicola was studied on the basis of UV/VIS,IR,MS spectrometric analysis and physicochemical constants.Results The pigment is proved to be hypocrellin A.The isolate was determined as the stable anamorphosis strain 0258 of S.bambusicola.Conclusion A namorphosis strain of S.bambusicola is obtained and precisely appraised for the first time.This study will provide basis for the future massively industrialized hypocrellin production.
3.Determination of plasma concentration of pachyman sulfate by spectrophotometry and its pharmacokinetics after intraperitoneal and intravenous administrations in rats.
Qun CHEN ; Aiyun WANG ; Qingcai JIAO
China Journal of Chinese Materia Medica 2010;35(22):3052-3055
OBJECTIVETo develop a spectral assay for determination of pachyman sulfate (PS) in rat plasma and to study the pharmacokinetics after intraperitoneal and intravenous administrations of PS.
METHODThe spectral probe azur A (AA) was used to measure the concentration of PS in rat plasma, since AA could combine the sulfate groups in PS molecules and consequently induced the color change in solution. The optimal wavelengths, concentrations of plasma and AA in reaction system were determined by spectral scanning and serial tests. The plasma PS concentrations were measured at different time after intraperitoneal and intravenous administrations at the dosage of 60 and 20 mg x kg(-1), respectively.
RESULTThe optimal detecting wavelength was 620 nm. The maximum concentration of plasma and the optimal concentration of AA were 1.25% and 8.24 x 10(-5) mol x L(-1) in reaction system, respectively. The calibration curve was linear over the range of 0-10 mg x L(-1) with a correlation coefficiency of 0.995 9. The mean recovery was 100. 55%. The relative standard deviation (RSD) of intra-group and inter-group were all less than 5%. After intraperitoneal and intravenous administrations, the corresponding elimination half-lives were 319.09 min and 204.85 min, respectively. The elimination of PS in blood matched the open model of one compartment and first-order elimination. The bioavailability of PS via intraperitoneal injection was 69.12%.
CONCLUSIONThe spectral probe AA was convenience, sensitive, accurate and steady to use for measuring the concentration of PS in the blood of rats; this made the research work of PS-pharmacokinetics easy and concise.
Animals ; Glucans ; administration & dosage ; blood ; pharmacokinetics ; Infusions, Intravenous ; Injections, Intraperitoneal ; Male ; Poria ; chemistry ; Rats ; Rats, Sprague-Dawley ; Spectrophotometry ; methods