An integrated process of cefaclor synthesis from phenylglycine methyl ester (PGME) and 7-aminodesacetoxymethyl-3-chlorocephalosporanic acid (7-ACCA) catalyzd by penicilin G acylase (PGA) with in situ product removal (ISRP) was estbilshd. The ntegrted process was more significantly influenced by temperature than the separate synthesis process as without ISPR. The difference between the overall yields with and without ISPR was minfied as reaction temperanres rose. For instance, the maximum 7-ACCA comversions was 86 and 68%, respectively, in the process with and without ISPR at 5℃. Both the maximum conversions. however, decreased to around 45% at 40℃. The effect of substrate concentration on the overall converion was also obviously dependent on the reaction temperiature. Te product cefaclor inhibited PGME hydroplysis in the enzymatic syathesis. ISPR stimulated cefacor synthesis at lower temperatures, but was not useful at hight temperatures which accelerated PGME hydrolysis.

Reconmbinatn antibodies, especially ScFv fragments can be applied as detection reagents and even substitute for some reagents used in immunoassays such as antibodyenzyme conjugates. For ScFv fragments there is no such universal system available up to now. A vector ystem was onstructed based on pPIC9-Fc, in which the hinge, CB2 and CB3 domin (Fe fragment) of mouse IgG1 and HIS-tag wee eloned into the Pichia expression vectro pPIC9. A model SeFv was introduced into pPIC9-Fc. which can bind Gluathione-S-transfrease (GST) from Schistsoma Japonicum to yield the fusion was expreessed at high levels in the methylotrphic yeast Pichia Pastoris, secreted as a dimeric form in the culture, ad purified by Ni2+-NTA column chromatography. The expression yield can reach 10-30mg/liter of culture medium. The SeFv-Fc fusio retains the bioglogyical binding ability of the parent Scfv, and can be applied as anti-GST antibodies for the detection of GST and GST-fusion proteins. Furthermore. the successful expression and maintenance of the binding activitv verify the efficacy of the vector system for use as detection reagents in vitro, by reacting with the specific antigens and being readily detected using general anti-mouse antibodies.

L-ascorbic acid 2-phosphate-6-palmiate (Asc2P6p) was synthesized and its effect on the damage of PC12 cells induced by H2O2 was investigted. 200μM H2O2 in a treatment pcriod of 4 hours in our experiment resulted in substantial cell loss. With the increasing concetration of antioxidants. such H2O2-induced cytotxicity was significantly prevented and the corresponding intracellular and extracellular ROS levels decreased concurrently by pre-treatment with Asc2P6P and Asc. It was found that Asc2P6P was superior to L-ascorbic acid in its protective role and showed a dose-depcndent manner during a 24-hour tretment. The higher potency of Asc2P6P's protective role on PC12 cells was correlated with its more effective ROS seavenging ability. HPLC assay its distinguished rle in protechiting PC12 cells againts H2O21-induced cytotoicity.

Oleic acid esters were shown to be the best carbon source for both cell growth and lipase production by Candlida rugosa. Use of cosolvent, dodecane, in fermentations improved the solubility of solid substrates and incresased oxygen solubility. This resulted in the hightst lipase ativity in batech fermentation with glycerol triolcate and dodecane. Lipase activity reached 77.1 units ml1.

Propyl-glycoside lacter, a new α-hydroxy acids derivative, was synthesized byesterification between lactic acid and propl-glycoside, instead oftransesteritication as reported previously, in a non-aqeous medium using immobilxed lipase as biocatalyst. A con ersion of 66% was achieved by the optimixation o the reaction conditions. Lipase activitywas found to be reduced when exposed to high conccentration mechanism of the enzymtic esterfication reaction. Additon of molecular sieves eliminated hydrolysis of the produced ester and allowed glycoside conversion rising to 75%