Mn Anwar

Isolation of mutants of Penicillium purpurogenum resistant to catabolite repression

Abstract The strain Penicillium purpurogenum P-26 was subjected to UV irradiation and N-methyl-N′-nitro-N-nitrosoguanidine treatment and mutants were isolated capable of synthesizing cellulase under the conditions of a high concentration of glucose. Initially mutants resistant to catabolite repression by 2-deoxy-D-glucose were isolated on Walseth’s cellulose/agar plates containing 15–45 mM 2-deoxy-D-glucose. These mutants were again screened for resistance to catabolite repression by glycerol or glucose on Walseth’s cellulose/agar plates containing 50 g/l glycerol or 50 g/l glucose respectively. Four mutants with different sizes of clearing zone on Walseth’s cellulose/agar plates containing 50 g/l glucose were selected for flask culture. Among them, the mutant NTUV-45-4 showed better carboxymethylcellulase activity in flask culture containing 1% Avicel plus 3% glucose than did the parental strain.

Selective Synthesis of Some New Carbohydrate Derivatives: Antimicrobial Screening Studies against Human and Phytopathogens

Methyl 4,6-O-benzylidene-α-D-glucopyranoside (1) was selectively converted to methyl 4,6-O-benzylidene-2-O-(2,6-dichlorobenzoyl)-α-D-glucopyranoside (2) by reaction with 2,6-dichlorobenzoyl chloride using direct method in good yield. Using a wide variety of acylating agents, a series of 3-O-acyl derivatives (2-10) of this 2-substitution product were also prepared. These synthesized derivatives were screened for in vitro antimicrobial activity against ten human pathogenic bacteria and three fungal phytopathogens. The study revealed that the acylated derivatives exhibit promising antibacterial and antifungal activities. The acylated derivatives were found to be more effective against the fungal strains than those of the bacterial pathogens. However, a good number of methyl 4,6-O-benzylidene-α-D-glucopyranoside derivatives exhibited better antimicrobial activity than the standard antibiotics.