Synthesis of some new quinazolinone derivatives and evaluation of their antimicrobial activities

Wide range of quinazolinone biological properties including: antibacterial, anticancer, and anti-inflammatory activities encouraged us to synthesis some fused quinazolinone derivatives. Anthranilic acid was condensed with chloro acylchloride followed by dehydration to form the benzoxazinone intermediate; subsequent addition of an amine provided the fused quinazolinones. Deoxyvasicinone which was previously synthesized by a multi step complex reactions was prepared in three steps using the following procedure: Log P values of the compounds were measured using the shake flask method in octanol/ water solvent system. The synthesized compounds were evaluated against six strains of bacteria [three Gram-positive and three Gram-negative] and three strains of fungi. Overall results of antimicrobial tests showed that the compounds had better bacteriostatic activity against Gram-negative bacteria. The obtained results of MBC revealed that these compounds had more significant bacteriostatic than bactericidal activities. Almost all of the screened compounds showed good activity against C. albicans and A. niger. The obtained results of MFC indicated that these compounds had more significant fungistatic than fungicidal activities

Optimization of the expression of genes encoding poly [3-hydroxyalkanoate] synthase from pseudomonas aeruginosa PTCC 1310 in escherichia coli

Over the years, the use of plastics has complicated the problem of disposal of solid wastes. One strategy to reduce plastic waste is the use of biodegradable plastics. A group of these plastics are polyhydroxyalkanoates [PHAs]. To date more than 250 different microorganisms are known to synthesize and accumulate PHA. Most Pseudomonas strains are able to accumulate mcl-PHA. In previous studies, the phaC1 and phaC2 genes were identified in Pseudomonas aeruginosa [P.aeruginosa] PTCC 1310 and were cloned. The aim of this study was to express these genes and optimize the conditions for their expression. The inserts obtained from vectors pTZPHAC1 and pTZPHAC2 were subcloned into pET15b expression vector. After transformation of competent Escherichia coli [E.coli] BL21 [DE3] cells with recombinant plasmids, expression was induced using IPTG. By changing expression conditions such as IPTG concentration, time and temperature of incubation with IPTG, the expression conditions for these enzymes were optimized, and the obtained results were compared using proper statistical analysis. The PHA synthase genes were induced with IPTG and the expressed 62 kDa protein was observed and purified. By changing expression conditions, 1 mM IPTG, 37°C and a 2 hr incubation provided the highest level of protein production in E.coli cells. These results suggest that induction condition of PhaC genes can influence expression of PHA synthase enzymes

Optimization of enzymatic synthesis of ampicillin using cross-linked aggregates of penicillin G acylase

Penicillin G acylase from E. coli TA1 was immobilized by Cross-Linked Enzyme Aggregates [CLEA], a new method for immobilization. This biocatalyst and commercial immobilized penicillin G acylase [PGA-450] were used to study the effect of pH, temperature and substrate concentration on the synthesis of ampicillin from phenyl glycine methyl ester [PGME] and 6-aminopenicillanic acid [6-APA]. Compared with PGA-450, this immobilized enzyme showed a high synthesis activity. The optimum conditions for synthetic activity was at pH 6, 25°C and 2:6 [6-APA:PGME] substrate ratio