Synthesis and biological evaluation of 4-oxycoumarin derivatives as a new class of antifilarial agents.

A series of 4-oxycoumarin derivatives was synthesized, characterized and evaluated in vitro and in vivo for antifilarial activity against the human lymphatic filarial parasite, Brugia malayi. A majority of the compounds studied showed potent in vitro activity with low IC50 values in the micro molar (µM) range (0.014-1.73 and 0.0056-0.43) against adult worms and microfilariae, respectively. Compounds 8 and 9 were identified to be the most promising antifilarial candidate molecules exhibiting activity in the nanomolar (nM) range. The IC50 values for compound 8 were 14 nM and 5.6 nM while for compound 9 were 94 nM and 13 nM, respectively, for adult worm and microfilaria. These two compounds also displayed promising adulticidal activity (74.9 ± 4.8% and 69.4 ± 2.8%, respectively) in the primary rodent (jird) screen. This study also serves as a starting point for investigating structure-activity relationship with different amino substituents.

Design, synthesis and biological evaluation of some new coumarin derivatives as potential antimicrobial agents.

A series of 4-methyl-7-O-substituted coumarins (3-12) was synthesized and evaluated for in vitro antimicrobial activity against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), four Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris) and three fungal strains (Candida albicans, Cryptococcus terreus and Saccharomyces cerevisiae) by two-fold serial dilution technique. The results of bioactive assay showed that some of the synthesized coumarins displayed comparable or even better antibacterial and antifungal activities against tested strains in comparison with reference drugs erythromycin, novobiocin and amphotericin B. Compound 9 showed potent antimicrobial activities against seven of the nine microbial strains examined in this study with MIC values ranging between 1.09 and 25 µg/mL and was the most active compound of the series. The present work also describes the effect of substituent on bioactivity.

Biopolymeric receptor for peptide recognition by molecular imprinting approach--synthesis, characterization and application.

The present work is focused on the development of a biocompatible zwitterionic hydrogel for various applications in analytical chemistry. Biopolymer chitosan was derivatized to obtain a series of zwitterionic hydrogel samples. Free amino groups hanging on the biopolymeric chain were reacted with γ-butyrolactone to quaternize the N-centers of polymeric chain. N,N-methylene-bis-acrylamide acts as a crosslinker via Michael-type addition in the subsequent step and facilitated gelation of betainized chitosan. These biopolymeric hydrogel samples were fully characterized by FTIR, (1)H NMR, (13)C NMR spectra, SEM and XRD. Hydrogels were further characterized for their swelling behavior at varying parameters. The extent of swelling was perceived to be dictated by solvent composition such as pH, ionic strength and temperature. This valuable polymeric format is herein chosen to design an artificial receptor for dipeptide 'carnosine', which has adequate societal significance to be analytically determined, by molecular imprinting. Electrostatic interactions along with complementary H-bonding and other hydrophobic interactions inducing additional synergetic effect between the template (carnosine) and the imprinted polymer led to the formation of imprinted sites. The MIP was able to selectively and specifically take up carnosine from aqueous solution quantitatively. Thus prepared MIPs were characterized by FTIR spectroscopy, SEM providing evidence for the quality and quantity of imprinted gels. The binding studies showed that the MIP illustrated good recognition for carnosine as compared to non-imprinted polymers (NIPs). Detection limit was estimated as 3.3 µg mL(-1). Meanwhile, selectivity experiments demonstrated that imprinted gel had a high affinity to carnosine in the presence of close structural analogues (interferrants).

Ectopic supernumerary tooth on the inferior nasal concha.

Variations regarding the location of an ectopic tooth in the human nasal cavity, although rare, are documented in the literature, but presence of an ectopic tooth on the inferior nasal concha (INC) has not been reported. We observed an anomalous tooth projecting from the posterior margin of the right INC in two adult female skulls. A small quadrangular tooth projected beyond the posterior margin of the hard palate in one of the skulls and a medium sized conical tooth was observed in the other skull. The affected INC in both skulls were located more inferiorly compared to the opposite side and were in close approximation with the hard palate. No similar findings were noted on the contralateral side nor were there any associated congenital or iatrogenic deformity. The phylogenetic, ontogenetic, and clinical importance of this variant is described. Knowledge of such an anomaly is of paramount importance to otorhinolaryngologists, reconstructive and dental surgeons, and radiologists for identification of such rarities encountered during invasive or non-invasive procedures.