Synthesis and Anticonvulsant Effect of Novel Thiazolidinedione Containing Benzene-sulfonylurea and Sulfonylthiourea Derivatives.

A newer series of 1-(4-substitutedphenyl)-3-(4-((2,4-dioxothiazolidin-5-lidene)methyl)phenyl sulfonyl)urea/thiourea (4a-l) were synthesized for their anticonvulsant activity. The activity is attributed to its potential to restrain astrocytic Na+, 2HCl, and K+ co-transport similar to torasemide which has sulfonylurea in its structure. Torasemide having the similar action as the furosemide that obstructs kainic acid-induced electrical discharges observed from cortex and it has neuroprotective agents, for instance antagonizing the N-methyl-D-aspartate (NMDA) and non-NMDA receptors for evaluating antiepileptic activity. The structures of new derivatives were established by elemental analysis and spectroscopic techniques viz. FTIR, 1H NMR and LC-MS. The all twelve derivatives were assessed for anticonvulsant activity at three different doses at 30, 100 and 300 mg/kg body weight into maximal electroshock (MES) and subcutaneous pentylenetetrazole (sports) models. Compounds 4c and 4e were formed to be most active among all the derivatives for both the models of anticonvulsant activity. Beside these compounds 4g, 4i and 4k also possessed the prominent anticonvulsant activity devoid of any neurotoxicity. The sulfonylurea and sulfonylthiourea both were proved to be effective anticonvulsant pharmacophore. Other structure activity relationships were established by considering the aspect of substitution in the lead.

Anticonvulsant and Neurotoxicity of Some Novel 1-([1,3,4]thiadiazino[6,5- b]indol-3-yl Semicarbazides.

In the present study a series of new N(4)-(4-substituted benzylidene)-N(1)-([1,3,4]thiadiazino [6,5-b]indol-3-yl)semicarbazide (1-6), N(4)-([1,3,4]thiadiazino[6,5-b]indol-3-yl)-N(1)-(1-(4-substituted phenyl)ethylidene)semicarbazide (7-10), N(4)-([1,3,4]thiadiazino[6,5-b]indol-3-yl)-N(1)-((4-substituted phenyl)(phenyl)methylene) semicarbazide. (11-14) have been synthesized from isatin and thiosemicarbazide through multiple steps to meet structural necessities for the anticonvulsant activity. All the newly prepared compounds were characterized by spectral techniques like FT-IR, (1)H and (13)C NMR, EI-MS and elemental analysis. All the newly synthesized compounds were investigated for the anticonvulsant activity against maximal electroshock induced seizures (MES) and subcutaneous pentylenetetrazole (scPTZ) models and their neurotoxicity were also evaluated by rotarod test. The results obtained showed that 64% of the compounds showed protection in the MES test and 36% of the compounds showed protection in ScPTZ test. Some of the compounds also showed good activity after oral administration. Among the synthesized compounds, compound 14 was shown to be the most active compound showing activity at 100 and 300 mg/kg in MES and ScPTZ test with prolonged duration of action. In the present study, semicarbazones of hydroxy containing carbonyl compounds were depicted to be the potent molecule with low neurotoxicity and prolong duration of action on oral administration. The result of the present study may be used for the future development of novel anticonvulsants with broad spectrum of anticonvulsant activity.

Chemical characteristics of aerosols and trace gas distribution over North and Central India.

A field campaign on aerosol chemical properties and trace gases measurements was carried out along the Delhi-Hyderabad-Delhi road corridor (spanning about 3,200 km) in India, during February 1-29, 2004. Aerosol particles were collected on quartz and cellulose filters using high volume (PM(10)) sampler at various locations along the route (i.e., urban, semi-urban, rural, and forest areas) and have been characterized for major cations (Na(+), Ca(2+), Mg(2+), K(+), and NH (4) (+)), anions (Cl(-), NO (3)(-), and SO (4)(2-)), and heavy metals (Cu, Cd, Fe, Zn, Mn, and Pb). Simultaneously, we measured NO(2) and SO(2) gases. These species show large spatial and temporal variations. The ambient PM(10) concentration has been observed to be the highest (55 ± 4 µg m(-3)) near semi-urban areas followed by forest areas (48 ± 2 µg m(-3)) and in rural areas (44 ± 22 µg m(-3)). The concentrations of NO( x ) (NO(2)+NO) and SO(2) ranged from 16 to 69 µg m(-3) and 4 to 11 µg m(-3), respectively. Among anions, NO(3)(-) and SO(4) (2-) are the major constituents of PM(10). The urban and semi-urban sites showed enhanced concentrations of Fe, Zn, Mn, Cd, and Pb. This study provide information about atmospheric concentrations of various species in the northern to central India, which may be important for policy makers to better understand the air quality of the region.

Greenhouse gas emissions from municipal solid waste management in Indian mega-cities: a case study of Chennai landfill sites.

Municipal solid waste generation rate is over-riding the population growth rate in all mega-cities in India. Greenhouse gas emission inventory from landfills of Chennai has been generated by measuring the site specific emission factors in conjunction with relevant activity data as well as using the IPCC methodologies for CH4 inventory preparation. In Chennai, emission flux ranged from 1.0 to 23.5mg CH4m(-2)h(-1), 6 to 460microg N2Om(-2)h(-1) and 39 to 906mg CO2m(2)h(-1) at Kodungaiyur and 0.9 to 433mg CH4m(-2)h(-1), 2.7 to 1200microg N2Om(-2)h(-1) and 12.3 to 964.4mg CO2m(-2)h(-1) at Perungudi. CH4 emission estimates were found to be about 0.12Gg in Chennai from municipal solid waste management for the year 2000 which is lower than the value computed using IPCC, 1996 [IPCC, 1996. Report of the 12th session of the intergovernmental panel of climate change, Mexico City, 1996] methodologies.

Methane and nitrous oxide emission from bovine manure management practices in India.

We report seasonal variation in CH(4) and N(2)O emission rate from solid storage of bovine manure in Delhi as well as emission factors and emission inventory from manure management systems in India. Emission flux observed in the year 2002-2003 was 4.29+/-1, 4.84+/-2.44 and 12.92+/-4.25 mg CH(4)kg(-1)dung day(-1), as well as 31.29+/-4.93, 72.11+/-16.22 and 6.39+/-1.76 microgN(2)O kg(-1)dung day(-1) in winter, summer and rainy seasons, respectively. CH(4) emission factors varied from 0.8 to 3.3 kg hd(-1)year(-1) for bovines and were lower than IPCC-1996 default values. N(2)O emission factors varied from 3 to 11.7 mg hd(-1)year(-1) from solid storage of manure. Inventory estimates were found to about 698+/-27 Gg CH(4) from all manure management systems and 2.3+/-0.46 tons of N(2)O from solid storage of manure for the year 2000.