Antimicrobial and larvicidal activities of 2-hydroxypyrrolidine/piperidine derivatives

Abstract

A novel series of various 2-hydroxypyrrolidine/piperidine derivatives were synthesized and their antibacterial activity against MTCC bacterial strains, anticancer activity and larvicidal effects were studied. Among the ten synthesized compounds, three were found to be antibacterial in nature. All the five test strains were highly sensitive to 1-(quinolin-3-yl) pyrrolidin-2-ol (P7), moderately sensitive to 1-(pyridin-4-yl) pyrrolidin-2-ol (P3) and less significantly to 1-(pyyrolidin-2-yl) piperidin-2-ol (p8). The maximum zone of inhibition was 28 ± 0.14 mm against Escherichia coli (MTCC 78) followed by 23± 0.14 mm against Klebsiella pneumoniae with 100 percent of relative inhibitory zone. The relative inhibitory zone of P3 against E.coli was 56% and 80 % against Klebsiella pneumoniae. Similarly 1-(quinolin-3-yl) pyrrolidin-2-ol (P7) showed a 60 % of larvicidal activity against Anaphelous sp and 53% against Culex sp. General Synthesis of 2-hydroxypyrrolidine/piperidine derivativesAmong the different approaches employed for the synthesis of 2-hydroxypyrrolidine and piperidine derivatives, one pot synthesis method is the most efficient. To the mixture of 2,3-cyclic ethers and acetonitrile, heterocyclic amine was added and followed by CeCl 3 .7H 2 O. The reaction condition was maintained at 60 °C using silicone oil bath and the contents were kept over a magnetic stirrer and stirred well. The colorless was solid separated and washed several times with water [12][13][14]. Antimicrobial effect of 2-hydroxy Pyrrolidine/ Piperdine derivatives (11=15)The antibiotic sensitivity of the isolates was determined using the disc diffusion method. Standardized inoculum of the 0.5 Mcfarnald overnight grown Nutrient agar culture of E. coli (MTCC 78), P. aeruginosa (MTCC 2488), S. aureus (MTCC 96), B. subtilis (MTCC 121), K. pneumoniae (MTCC 109) were spread on Mueller-Hinton agar plates using sterile swabs. The plates were dried at room temperature for 20 min and 100 µl (5 mg /ml) of synthesized pyrrolidine and piperidine derivatives loaded on their respective wells and allowed to diffuse. The plates were incubated for 24 h at 37°C. All the tests were triplicate and the diameter of zone of inhibition was measured and statistically reported [15]. Screening of larvidial effect of 2-hydroxy Pyrrolidine/ Piperdine derivativesAbout 100 ml of sterile tap water was taken in conical flask and one ml of pyrrolidine and piperidine derivatives were added to obtain 10 ppm concentration. The control tubes were maintained as tap water alone. 25 numbers of 3 rd instar Anopheleses and Culex mosquito larvae were inoculated into the above tubes and incubated at 2°C for 48 h. The larvicidal activity was observed for over 30 min. and death of the larvae confirmed the larvicidal activity. The experiment was checked daily for recording the biological effects of following criterias [19].Larval mortality percent: was estimated by using the following equation:Larval mortality % = A -B / A × 100Where A = number of tested larvae and B = number of tes...