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Candida spp., along with other microorganisms are usually found in the normal flora of the human oral mucosa. However in HIV-infected individuals these yeasts can become opportunistic pathogens and lead to mucosal infections. The transformation from a harmless commensal to a virulent pathogen under conditions of dysfunctional host defense system is attributable to an extensive repertoire of selectively expressed virulence determinants. The present study was undertaken to analyze the production of four important virulence factors viz. adherence to buccal epithelial cells (BEC), proteinase activity, phospholipase activity and hemolysis, and to evaluate the correlation between these virulence factors in 65 Candida isolates from HIV-infected individuals with oral candidiasis. A total of 95.3%, 67.7%, 41.5% and 100% of the Candida isolates showed adherence to BEC, and proteinase, phospholipase and hemolytic activities, respectively. Production of proteinase and phospholipase enzymes was seen in 89.7% and 59.0% of C. albicans isolates and 34.6% and 15.4% of non-Candida albicans Candida (NAC) isolates, respectively. C. albicans showed significantly greater level of virulence factor expression with regards to adherence to BEC (P < 0.001), phospholipase production (P < 0.044) and hemolysis (P = 0.037) as compared to NAC. A correlative relationship between proteinase activity and adherence to BEC, as well as phospholipase production was noted.

8‐Hydroxyquinoline, being one of the privileged scaffolds, is known to possess a wide range of biological activities. 8‐Hydroxyquinoline quinoline has been explored synthetically through functionalization at different positions by different groups in search of medicinally important molecules. Herein, we synthesized twenty‐one (20 a‐20 u) different hydrazones of 8‐hydroxyquinoline at C‐2 position in good yields and characterised by 1H NMR, 13C NMR, HRMS and IR. All the synthesized compounds were evaluated for their anti‐HIV‐1 and anti‐cancer potential through in vitro cell‐based assays. Compound 20 u ((E)‐2‐((2‐(4‐methoxyphenyl)hydrazono)methyl)quinolin‐8‐ol) was found to be the most active against HIV (IC50: 1.88 and 6.27 μM; TI 73.82 and 22.07, against HIV‐1VB59 and HIV‐1UG070 respectively). Compound 20 l ((E)‐2‐((2‐(4‐fluorophenyl)hydrazono)methyl)quinolin‐8‐ol) was identified as the most cytotoxic against four cancer cell lines (IC50: 26.30, 34.19, 38.77 and 34.23 μM against HeLa, MCF‐7, A‐549 and MDA‐MB‐231, respectively) with 2.4, 1.9, 1.6, 1.9‐folds selectivity, respectively over normal cells (IC50 63.75 μM against HEK‐293 normal cells).

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The production of 6-aminopenicillanic acid (6-APA) is a key step in the manufacture of semisynthetic antibiotics in the pharmaceutical industry. The penicillin G acylase from Escherichia coli has long been utilized for this purpose. However, the use of penicillin V acylases (PVA) presents some advantages including better stability and higher conversion rates. The industrial application of PVAs has so far been limited due to the nonavailability of suitable bacterial strains and cost issues. In this study, whole-cell immobilization of a recombinant PVA enzyme from Pectobacterium atrosepticum expressed in E. coli was performed. Membrane permeabilization with detergent was used to enhance the cell-bound PVA activity, and the cells were encapsulated in calcium alginate beads and cross-linked with glutaraldehyde. Optimization of parameters for the biotransformation by immobilized cells showed that full conversion of pen V to 6-APA could be achieved within 1 hr at pH 5.0 and 35°C, till 4% (w/v) concentration of the substrate. The beads could be stored for 28 days at 4°C with minimal loss in activity and were reusable up to 10 cycles with 1-hr hardening in CaCl between each cycle. The high enzyme productivity of the PVA enzyme system makes a promising case for its application for 6-APA production in the industry.