A regio- and stereoselective 1,3-dipolar cycloaddition for the synthesis of new-fangled dispiropyrrolothiazoles as antimycobacterial agents.

A series of dispiropyrrolothiazoles compounds were synthesized using 1,3-dipolar cycloaddition and were screened for antimycobacterial activity against Mycobacterium tuberculosis H(37)Rv and INH resistant M. tuberculosis strains. Two of them were showing good activity with MIC of less than 1 µM. Compound (5f) was found to be the most active with MIC of 0.210 and 8.312 µM respectively.

Synthesis and discovery of novel hexacyclic cage compounds as inhibitors of acetylcholinesterase.

Hexacyclic derivatives share vital pharmacological properties, considered useful in Alzheimer's disease. The aim of this study was synthesis and its evaluation for acetyl cholinesterase inhibitory activity of novel hexacyclic analogues. Compound 4f, showed potent inhibitory activity against acetyl cholinesterase enzyme with IC(50) 0.72 µmol/L.

Bis dihydropyrimidine: synthesis and antimycobacterial activity.

A series of bis dihydropyrimidine compounds were synthesised by reacting dapsone with acetylacetoacetate to produce N1-4-[4-(2-oxopropylcarboxamido) phenylsulphonyl] phenyl-3-oxobutanamide, then treated with guanidine hydrochloride and an appropriate aldehyde with a catalytic amount of p-toluene sulphonic acid (PTSA) in the presence of methanol to afford the title compounds. The synthesised compounds were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis H(37)Rv and isoniazid (INH) resistant M. tuberculosis. Among the synthesised compounds, compound N5-(4-4-[6-(4-fluorophenyl)-2-imino-4-methyl-1,2,3,4-tetrahydro-5-pyrimidinylcarboxamido]phenylsulphonylphenyl)-6-(4-fluorophenyl)-2-imino-4-methyl-1,2,3,4-tetrahydro-5-pyrimidine carboxamide (3g) was found to be the most promising compound with activity against M. tuberculosis H(37)Rv and INH resistant M. tuberculosis with a minimum inhibitory concentration (MIC) between 0.08 and 0.10 µM.

Antimycobacterial activity: synthesis of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues.

In this study, a series of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues were synthesized and evaluated for antimycobacterial activity against Mycobacterium tuberculosis (MTB) H(37)Rv and isoniazid resistant M. tuberculosis (INHR-MTB). All the newly synthesized compounds were showing moderate to high inhibitory activities. The compound 6,7-dimethoxy-3-(4-chloro phenyl)-4H-indeno[1,2-c]isoxazole (4b) was found to be the most promising compound, active against MTB H(37)Rv and INHR-MTB with minimum inhibitory concentrations of 0.22 and 0.34 µM.

Discovery of novel methanone derivatives acting as antimycobacterial agents.

A series of pyrazoline derivatives were synthesized and in vitro activity against Mycobacterium tuberculosis H37Rv was carried out. Among the synthesized compounds, compounds (4d) and (4f) 4-aminophenyl-3-(3,4-dimethoxyphenyl)-6,7-dimethoxy-2,3,3a,4-tetrahydroindeno[1,2-c]pyrazol-2-ylmethanone and 4-aminophenyl-6,7-dimethoxy-3-phenyl-2,3,3a,4-tetrahydroindeno[1,2-c]pyrazol-2-ylmethanone were found to be the most active agent against M. tuberculosis H37Rv with a minimum inhibitory concentration of 10 µg/mL.

Synthesis and anti-HIV activity of novel 3-substituted phenyl-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues.

A series of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues were synthesized by the reaction of 5,6-dimethoxy-2-[(E)-1-phenylmethylidene]-1-indanone with hydroxylamine hydrochloride. The title compounds were tested for their in vitro anti-HIV activity. Among the compounds, (4g) showed a promising anti-HIV activity in the in vitro testing against IIIB and ROD strains. The IC50 of both IIIB and ROD were found to be 9.05 microM and > 125 microM, respectively.

Substituted spiro [2.3'] oxindolespiro [3.2″]-5,6-dimethoxy-indane-1″-one-pyrrolidine analogue as inhibitors of acetylcholinesterase.

Series of pyrolidine analogues were synthesized and examined as acetylcholinesterase (AChE) inhibitors. Among the compounds, compounds 4k and 6k were the most potent inhibitors of the series. Compound 4k, showed potent inhibitory activity against acetyl cholinesterase enzyme with IC(50) 0.10 µmol/L. Pyrolidine analogues might be potential acetyl cholinesterase agents for AD.

Design, synthesis and evaluation of novel 5,6-dimethoxy-1-oxo-2,3-dihydro-1H-2-indenyl-3,4-substituted phenyl methanone analogues.

In present investigation, a series of substituted phenyl-5,6-dimethoxy-1-oxo-2,3-dihydro-1H-2-indenylmethanone analogues were synthesized and were tested for their potential for treating AD disease. All the newly synthesized compounds were showing moderate to high AChE inhibitory activities, with compound 5,6-dimethoxy-1-oxo-2,3-dihydro-1H-2-indenyl-3,4,5-trimethoxyphenylmethanone (5f) produced significant activities with 2.7+/-0.01 micromol/L.

Synthesis and antimycobacterial evaluation of novel 5,6-dimethoxy-1-oxo-2,5-dihydro-1H-2-indenyl-5,4-substituted phenyl methanone analogues.

In present investigation, a series of substituted phenyl-5,6-dimethoxy-1-oxo-2,5-dihydro-1H-2-indenylmethanone analogues were synthesized and were evaluated for antimycobacterial activity against Mycobacterium tuberculosis H(37)Rv and INH resistant M. tuberculosis. All the newly synthesized compounds were showing moderate to high inhibitory activities. The compound 5,6-dimethoxy-1-oxo-2,5-dihydro-1H-2-indenyl-4-fluorophenylmethanone (5g) was found to be the most promising compounds active against M. tuberculosis H(37)Rv and isoniazid (INH) resistant M. tuberculosis with Minimum inhibitory concentration 0.10 and 0.10 microM.

Seasonal distribution and population dynamics of limnic microalgae and their association with physico-chemical parameters of river Noyyal through multivariate statistical analysis.

The present investigation embarks on understanding the relationship between microalgal species assemblages and their associated physico-chemical parameter dynamics of the catchment region of river Noyyal. Totally, 142 microalgae cultures belonging to 10 different families were isolated from five different sites during four seasons and relative percentage distribution showed that Scenedesmaceae (36.6%) and site S1 (26.4%) with predominant microalgae population. Diversity indices revealed that microalgae communities were characterized by high H' index, lower Simpson dominance, and Margalef index value with indefinite patterns of annual variations. Results showed that variation in the physico-chemical parameters in each sampling site has its impact on the microalgae population during each season. Multivariate statistical analysis viz., Karl Pearson's correlation coefficient, principal component analysis, and canonical correspondence analysis were applied on microalgae species data, to evaluate the seasonal relationship between microalgae and physico-chemical parameters. The findings of our study concluded that the physico- chemical parameters influenced the dominant taxa of microalgae Chlorellaceae, Scenedesmaceae and Chlorococcaceae in river Noyyal and gives a base data for the seasonal and dynamic relationship between environmental parameters and microalgae population.

An open-terrain line source model coupled with street-canyon effects to forecast carbon monoxide at traffic roundabout.

A double-lane four-arm roundabout, where traffic movement is continuous in opposite directions and at different speeds, produces a zone responsible for recirculation of emissions within a road section creating canyon-type effect. In this zone, an effect of thermally induced turbulence together with vehicle wake dominates over wind driven turbulence causing pollutant emission to flow within, resulting into more or less equal amount of pollutants upwind and downwind particularly during low winds. Beyond this region, however, the effect of winds becomes stronger, causing downwind movement of pollutants. Pollutant dispersion caused by such phenomenon cannot be described accurately by open-terrain line source model alone. This is demonstrated by estimating one-minute average carbon monoxide concentration by coupling an open-terrain line source model with a street canyon model which captures the combine effect to describe the dispersion at non-signalized roundabout. The results of the modeling matched well with the measurements compared with the line source model alone and the prediction error reduced by about 50%. The study further demonstrated this with traffic emissions calculated by field and semi-empirical methods.

Purification, immobilization, and characterization of nattokinase on PHB nanoparticles.

In this study, nattokinase was purified from Bacillus subtilis using ion exchange chromatography and immobilized upon polyhydroxybutyrate (PHB) nanoparticles. A novel strain isolated from industrial dairy waste was found to synthesize polyhydroxyalkanoates (PHA) and the strain was identified as Brevibacterium casei SRKP2. PHA granules were extracted from 48 h culture and the FT-IR analysis characterized them as PHB, a natural biopolymer from B. casei. Nanoprecipitation by solvent displacement technique was used to synthesize PHB nanoparticles. PHB nanoparticles were characterized using transmission electron microscopy and particle size ranged from 100-125 nm. Immobilization of nattokinase upon PHB nanoparticles resulted in a 20% increase in the enzyme activity. Immobilization also contributed to the enhanced stability of the enzyme. Moreover, the activity was completely retained on storage at 4 degrees C for 25 days. The method has proven to be highly simple and can be implemented to other enzymes also.