Udaya Pratap Singh

Physicochemical characterization and in vitro dissolution studies of solid dispersions of ketoprofen with PVP K30 and d-mannitol.

Aim of the present study was to improve the solubility and dissolution rate of poorly water soluble, BCS class-II drug Ketoprofen (KETO) by solid-dispersion approach. Solid dispersions were prepared by using polyvinylpyrrolidone K30 (PVP K30) and d-mannitol in different drugs to carrier ratios. Dispersions with PVP K30 were prepared by kneading and solvent evaporation techniques, whereas solid dispersions containing d-mannitol were prepared by kneading and melting techniques. These formulations were characterized in the liquid state by phase-solubility studies and in the solid state by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The aqueous solubility of KETO was favored by the presence of both carriers. The negative values of Gibbs free energy illustrate the spontaneous transfer from pure water to the aqueous polymer environment. Solid state characterization indicated KETO was present as fine particles in d-mannitol solid dispersions and entrapped in carrier matrix of PVP K30 solid dispersions. In contrast to the very slow dissolution rate of pure KETO, dispersions of drug in carriers considerably improved the dissolution rate. This can be attributed to increased wettability and dispersibility, as well as decreased crystallinity and increase in amorphous fraction of drug. Solid dispersions prepared with PVP K30 showed the highest improvement in dissolution rate of KETO. Even physical mixtures of KETO prepared with both carriers also showed better dissolution profiles than those of pure KETO.

Antifungal activity, SAR and physicochemical correlation of some thiazole-1,3,5-triazine derivatives.

OBJECTIVE Present research communication was towards the investigation of antifungal minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) activity of some substituted clubbed thiazole-1,3,5-triazines derivatives and effect of physicochemical properties on bioactivity. MATERIAL AND METHODS MIC and MFC were evaluated against Candida albicans, Candida glabrata, Cryptococcus neoformans and Aspergillus niger using modified microdilution method recommended by CLSI. Cytotoxicity was determinate on the viability of marine shrimp larvaes. SAR and physicochemical correlations were studied by Molinspiration software. RESULTS The 5 and 9 derivatives showed an excellent antifungal activity with MIC lower than fluconazole and equivalent to amphotericin B specially against C. albicans and C. glabrata. The toxicity of these two derivatives was non-existent for 5 and moderate for 9 at the used concentration. SAR study around prototype molecule suggests that presence of di-hydrophobic fragment on 1,3,5-triazine is necessary for antifungal activity than halogen substituted aromatic amine. CONCLUSION On the basis of selectivity, potency and non-toxicity, we have obtained two molecules (5 and 9) as prospective leads for further research work on 1,3,5-triazine as antifungal drug.

Antimalarial evaluation and docking studies of hybrid phenylthiazolyl-1,3,5-triazine derivatives: A novel and potential antifolate lead for Pf-DHFR-TS inhibition

Present communication deals with the docking study of hybrid phenyl thiazolyl-1,3,5-triazine analogues (1a-36d) on three selected different binding site viz., α, β and γ of wild type Pf-DFHR-TS. In admiration of excellent H-bond scoring, with regard to cycloguanil and to a large extent similar scoring with WR99210, compound 4a, 12b, 21c, 23c, 28d, 29d, 34d, and 35d were selected for in vitro antimalarial activity against 3D7 strain of Plasmodium falciparum. Findings from the study disclose that a significant correlation was exist between in vitro results and in silico prediction (r(2)=0.543). Furthermore, investigation of structure-activity relationships elucidate crucial structural requirement for site specific binding of ligands.

Synthesis and antibacterial evaluation of series of novel tri-substituted-s-triazine derivatives

Two novel series of s-triazine derivatives (6a–e and 7a–f) were synthesized with various aromatic and heterocyclic amines. The synthesized compounds were subsequently evaluated for their in vitro antibacterial activity against three gram-positive viz. Bacillus subtilis (NCIM-2063), Bacillus cereus (NCIM-2156), Staphylococcus aureus (NCIM-2079) and gram-negative bacteria viz. Pseudomonas aeruginosa (NCIM-2036), Escherichia coli (NCIM-2065) and Klebseilla pneumoniae (NCIM-2706) by the broth dilution method as recommended by the National Committee for Clinical Laboratory Standards (NCCLS) using streptomycin as reference standard. Structures of the synthesized compounds were elucidated on the basis of elemental analyses and spectral data.

Antimalarial activity and docking studies of novel bi-functional hybrids derived from 4-aminoquinoline and 1,3,5-triazine against wild and mutant malaria parasites as pf-DHFR inhibitor

Bi-functional conjugates comprised of 4-aminoquinoline and 1,3,5-triazine were synthesized through facile synthetic routes. These compounds were rigorously screened for determination of their antimalarial activity against wild and mutant cultured Plasmodium falciparum. The results disclosed that the conjugates have considerable antimalarial activity against both wild and mutant parasites with marked variation on changing the pattern of substitutions. The observed activity profiles were additionally substantiated by docking studies on both wild and quadruple mutant P. falciparum dihydrofolate reductase thymidylate synthase (pf-DHFR-TS).

4-Aminoquinoline-1,3,5-triazine: Design, synthesis, in vitro antimalarial activity and docking studies

A series of hybrid 4-aminoquinoline 1,3,5-triazine derivatives was synthesized and their chemical structure were confirmed by 1H-NMR, 13C-NMR, FT-IR and mass spectrometric analyses. In vitro antimalarial activity of these compounds was evaluated against chloroquine-sensitive (3D-7) and chloroquine resistant (RKL-2) strains of P. falciparum. Results showed that all compounds had considerable antimalarial activity against both the strains and further docking studies were performed on both wild type (1J3I.pdb) and quadruple mutant (N51I, C59R, S108 N, I164L, 3QG2.pdb) pf-DHFR-TS to quantify the structural parameter necessary for the activity.

Synthesis, SAR and antibacterial activity of hybrid chloro, dichloro-phenylthiazolyl-s-triazines

A series of hybrid novel chloro (1a-9a) and dichloro (10b-18b) phenylthiazolyl-s-triazine were synthesized and subsequently subjected to their antibacterial activity against three gram positive viz. Lactobacillus casei (NCIM-2651); Bacillus cereus (NCIM-2458); Staphylococcus aureus (NCIM-2120) and three gram negative viz Salmonella typhimurium (NCIM-2501); Escherichia coli (NCIM-2065); Klebsiella aerogenes (NCIM-2098). The SAR studies around the lead compound revealed that introduction of electron withdrawing groups and amino (-NH-) and mercapto (-S-) linker bridge seemed more promising towards antibacterial activity. Moreover, the virtual Molinspiration screenings are in compliance with Ghoses rule.

Design, Synthesis, Antibacterial Activity, and Molecular Docking Studies of Novel Hybrid 1,3- Thiazine-1,3,5-Triazine Derivatives as Potential Bacterial Translation Inhibitor

Some novel hybrid 1,3‐thiazine‐1,3,5‐triazine derivatives were synthesized and tested for antibacterial activity. Compounds 8c and 8f were found active against Gram positive and Gram negative microorganisms. Molecular docking studies have been performed on eubacterial ribosomal decoding A site (Escherichia coli 16S rRNA A site) to rationalize the probable mode of action, binding affinity, and orientation of the molecules at the active site of receptor. The structures of all these newly synthesized compounds were confirmed by their elemental analyses and spectral data techniques viz. IR, 1H NMR, 13C NMR, and mass.

Design, Facile Synthesis, and Antibacterial Activity of Hybrid 1,3,4-thiadiazole-1,3,5-triazine Derivatives Tethered via -S- Bridge

Some hybrid 1,3,4‐thiadiazole‐1,3,5‐triazine derivatives tethered via –S– bridge were synthesized and characterized with the aid of spectroscopic and elemental analysis. These hybrid conjugates were then investigated for their antibacterial activity against selected Gram‐positive and Gram‐negative bacteria. Excellent to moderate antibacterial activity was presented by the target compounds.

Design and one-pot synthesis of hybrid thiazolidin-4-one-1,3,5-triazines as potent antibacterial agents against human disease-causing pathogens

An efficient and general one-pot reaction to a novel series of hybrid thiazolidine-4-one-1,3,5-triazine derivatives was developed. The easy work-up of the products, rapid reaction, and mild conditions are notable features of this protocol. These molecules were found to exhibit potent activity against a panel of Gram-positive and Gram-negative micro-organisms.