Biologically active scaffolds: Synthesis, characterization and studies of oxino bis-pyrazoles by environmental friendly method.

In the present communication, synthesis of bis-pyrazolones containing aryl motifs (4-14) and their α-glucosidase inhibitory activity, hemolytic and antihemolytic activities were reported. The newly synthesized compounds were characterized by analytical techniques such 1H-NMR, 13C-NMR, IR, mass spectrometry and compound No 4 additionally by X-ray crystallography. Compounds 4, 12, 14 were obtained in more than 85% yield. In comparison to typical acarbose (IC50 = 37.38±0.12µM), all synthesized compounds showed potent activity with IC50 values between 31.26±0.11 to 396.25±0.18µM. The most potent compounds 6, 8 and 11 showed IC50 values within the range of 31.26±0.11 to 37.48±0.12µM. Compounds 7, 10, 12 and 13 showed IC50 values within the range of 65.23±0.12 to 154.87±0.16µM, while compounds 4, 5 and 9 showed moderate inhibition with IC50 values 286.56±0.16 to 396.25±0.18µM. Structure-activity relationship (SAR) studies, suggests that electron withdrawing groups played a crucial role in enhancing α-glucosidase inhibitory effects of title compounds. In addition, results of the hemolytic and antihemolytic activity studies indicated that compound 13 possessed moderate levels of hemolytic and highest anti- hemolytic activity while 8 showed low anti- hemolytic and high hemolytic activity.

Synthetic N-[(substitutedsulfamoyl)phenyl]acetamides as moderate chymotrypsin inhibitors.

A facile method has been implemented for the synthesis of different N-substituted sulfamoylacetamides by reacting 4-acetamidobenzenesulfonyl chloride (1) with different alkyl/aralkyl/aryl amines (2a-q) in basic aqueous media under controlled pH to afford -[(Substitutedsulfamoyl) phenyl]acetamides (3a-q) which were confirmed through spectral analysis like FT-IR, EIMS and 1H-NMR. Moreover, the synthesized derivatives were screened against α-Chymotrypsin. The enzyme inhibitory results revealed that most of the synthesized compounds were found to be moderate enzyme inhibitors.

Determination of nitrate in biological fluids by HPLC.

Nitrate is the stable product of nitric oxide, which is physiologically active radical, an immunomodulator and a neuromodulator; its quantification in biological fluids is important to study the physiological and biochemical nature. Therefore, the purpose of this study was to quantify nitrate in different biological fluids like serum, cerebrospinal fluid (CSF) and ascetic fluid (ASF) using HPLC technique. A new HPLC method for the estimation of nitrate in serum, CSF and ASF was developed using the mobile phase of 1.0mM each of Na2CO3 and NaHCO3 (1:1, v/v, pH 5 with H3PO4) at a flow rate of 1.0mLmin-1. Eluate was detected at 220nm with the retention time of nitrate 2.55 min. The LOD and LOQ values of nitrate were 0.03µgmL-1 and 0.098µgmL-1, respectively. Nitrate was eluted through SAX Hypersil column of 150 × 4.6mm, id, 5µm particle size. Run time was 10min. The method was validated according to the FDA guidelines and was found linear in the range of 0.39 to 50µgmL-1 and CV was <3%, within limits of FDA guidelines. The method was used successfully for the estimation of nitrate in biological fluids like serum, CSF and ASF of 20 patients each. This is an alternate and reproducible method for the detection of nitrates in biological fluids.

Discovery of indole-based tetraarylimidazoles as potent inhibitors of urease with low antilipoxygenase activity.

A series of tetraarylimidazoles (5A-5O) were prepared by one pot four component condensation reactions of 2-arylindole-3-carbaldehydes, substituted anilines, benzil and ammonium acetate in acetic acid. The synthesized compounds exhibited potent antiurease activity with IC50 values ranging from 0.12 ± 0.06 µM to 29.12 ± 0.18 µM as compared with thiourea. However, low inhibition profiles were observed for lipoxygenase. The data show that tetraarylimidazoles containing a substituted 2-penylindole have emerged as a new class of potent inhibitors of urease enzyme.

Synthesis of novel quinoxalinone derivatives by conventional and microwave methods and assessing their biological activity.

In this study, twenty-one arylaminoquinoxalinone derivatives were synthesized and their antibacterial activities against Staphylococci aureus, Pseudomonas aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, and Shigella pneumoniae were evaluated relative to known antibiotics; augmentin, ampicillin, and chloramphenicol. The insecticidal activities of the prepared compounds were also investigated against Tribolium castaneum using permethrin as a standard insecticide. The derivatives were synthesized using both conventional and microwave techniques. Their structures were confirmed using spectral techniques and elemental analysis.