Seasonal variation in photosynthetic rates and satellite-based GPP estimation over mangrove forest.

In view of increasing anthropogenic influences and global changes, quantification of carbon assimilation through photosynthesis has gained tremendous significance. Precise estimation of Gross Primary Productivity (GPP) is essential for several ecosystem models and is typically done using coarser scale satellite data. The mangrove ecosystem, which offers significant protection to the coastal environment, is one of the critical habitats from a global change point of view. Light use efficiency (LUE) was measured using diurnal in situ photosynthetic rate observations for 13 dominant mangrove species for 3 seasons at each of the three mangrove dominant test-sites situated along the east and west coast of India. Variations in photosynthetic rates among these species were studied for 3 seasons that indicated varying responses of mangrove ecosystem at each site. Among all species, Rhizophora mucronata and Sonneratia apetala indicated higher values at two of the test-sites. IRS Resourcesat-2 LISS-IV datasets were used for the estimation of GPP. Mean GPP for all the sites varied from 1.2 to 7.7 g C m-2 day-1 with maximum value of 14.4 g C m-2 day-1. Mean values of GPP varied across the sites, based on its maximum LUE values and available photosynthetically active radiation (PAR). The results provide GPP values at much better spatial resolution for a threatened habitat like mangroves that typically survive in a narrow habitat along the coasts.

Effect of coadministration of moxifloxacin and rifampin on Mycobacterium tuberculosis in a murine aerosol infection model.

Coadministration of moxifloxacin and rifampin was evaluated in a murine model of Mycobacterium tuberculosis pulmonary infection to determine whether the finding of antagonism documented in a hollow-fiber infection model could be recapitulated in vivo. Colony counts were followed in a no-treatment control group, groups administered moxifloxacin or rifampin monotherapy, and a group administered a combination of the two agents. Following 18 days of once-daily oral administration to mice infected with M. tuberculosis, there was a reduction in the plasma exposure to rifampin that decreased further when rifampin was coadministered with moxifloxacin. Pharmacodynamic analysis demonstrated a mild antagonistic interaction between moxifloxacin and rifampin with respect to cell kill in the mouse model for tuberculosis (TB). No emergence of resistance was noted over 28 days of therapy, even with monotherapy. This was true even though one of the agents in the combination (moxifloxacin) induces error-prone replication. The previously noted antagonism with respect to cell kill shown in the hollow-fiber infection model was recapitulated in the murine TB lung model, although to a lesser extent.

1-(3-Bromo-2-thien-yl)ethanone.

In the title compound, C(6)H(5)BrOS, the non-H and aromatic H atoms lie on a crystallographic mirror plane. In the crystal, mol-ecules are linked into chains propagating along the c axis by inter-molecular C-H⋯O hydrogen bonds.

Antiangiogenic and antiproliferative effects of substituted-1,3,4-oxadiazole derivatives is mediated by down regulation of VEGF and inhibition of translocation of HIF-1alpha in Ehrlich ascites tumor cells.

PURPOSE: 1,3,4-Oxadiazoles are an important class of heterocyclic compounds, which play a pivotal role in various pharmaceutical applications. Here, we investigated the antiangiogenic and antiproliferative effects of the derivatives and explored its mechanism of action on EAT cells. METHODS: The cytotoxic effect of the derivatives on EAT and HEK293 cells was assessed by MTT assay. Effect of the derivatives on ALP activity and proliferation was measured. Swiss albino mice transplanted with EAT cells were used as a model system to study the effect of the derivatives in vivo. Inhibition of angiogenesis in mice peritoneum, CAM and Cornea of the rat were studied. Finally, the effects on VEGF gene expression, HIF-1alpha translocation and cell cycle arrest were determined. RESULTS: The IC50 range for growth inhibition of EAT cells was found to be 140-175 microM. In contrast normal HEK293 cells were resistant to the derivatives at this range. Treatment with derivatives in vivo was demonstrated by the down regulation of VEGF in EAT cells and inhibition of blood vessels formation in mice peritoneum, CAM and cornea of rat, indicating the potent angioinhibitory effect of the derivatives. VEGF promoter-luciferase reporter gene expression analysis showed suppression of VEGF gene expression in vitro. The derivatives proved to be potent antiproliferative agents as shown by FACS analysis and decreased ALP activity. Furthermore, expression of HIF-1alpha was also down regulated by derivatives by repressing its nuclear translocation. CONCLUSIONS: Oxadiazole derivatives are strong bioactive compounds with antiangiogenic and antiproliferative potential both in vitro and in vivo. We postulate that diminished HIF-1alpha nuclear presence in oxadiazole treated EAT cells could be responsible for decreased VEGF expression and antiangiogenic effects.

Synthesis of new series of 5,6-dihydro-4H-1,2-oxazines via hetero Diels-Alder reaction and evaluation of antimicrobial activity.

A new series of 5,6-dihydro-4H-1,2-oxazines were synthesized via hetero Diels-Alder reaction of alpha-nitrosoolefins with alkenes. alpha-Nitrosoolefins were generated from ketoximes by the action of chloramine-T. The newly synthesized compounds were characterized with IR, NMR, elemental analysis and screened for their antimicrobial activity; they exhibited excellent antimicrobial activity. The minimal inhibitory concentration of the compounds was in the range of 10-35 microg ml(-1) for bacteria and 10-40 microg ml(-1) for fungi.

Growth inhibition and induction of apoptosis in MCF-7 breast cancer cells by a new series of substituted-1,3,4-oxadiazole derivatives.

The multiple pharmacological actions of unique synthetic compounds are a prerequisite for classifying a drug as highly efficacious, because the multiple pharmacological actions offer the possibility of treating various diseases like cancer. 1,3,4-Oxadiazoles are an important class of heterocyclic compounds with broad spectrum of biological activities. In this study we focused on the ability of these derivatives to induce apoptosis in cultured MCF-7 breast cancer cells. Treatment of MCF-7 cells with varying concentrations of the different derivatives resulted in dose and time dependent sequence of events marked by apoptosis, as shown by loss of cell viability, chromatin condensation, internucleosomal DNA fragmentation and sub G(0) phase accumulation. Furthermore, apoptosis in MCF-7 cell was induced by upregulation of proto-oncoprotein Bax and activation of Caspase-3 activated DNase. Although the derivatives induced apoptosis was associated with Bax protein levels, negligible Bcl-2 reduction was observed. Analysis of the data suggests that the substituted oxadiazole derivatives exert antiproliferative action and growth inhibition on MCF-7 cells through apoptosis induction and that it may have anticancer properties valuable for application in drug products.

Synthesis and screening for acetylcholinesterase inhibitor activity of some novel 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-ones: derivatives of irbesartan key intermediate.

The association of bioactive nucleus with other pharmacological agents is hoped to improve the efficacy of the treatment by combining the effects of different pharmacological mechanisms of action. Keeping this in view, a series of 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-one derivatives have been synthesized by interaction of 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-one with different bioactive aralkyl halides in presence of powdered potassium carbonate by two different methods viz., conventional and microwave irradiation. The yields under conventional and microwave irradiation methods were in the range of 60-65% and 80-90%, respectively. The structure elucidation of the new compounds has been carried out with the help of elemental analysis and spectral data. All the synthesized compounds have been screened for their efficacy as acetylcholinesterase (AChE) inhibitor. AChE inhibitory activity study was carried out by using Ellman colorimetric assay with neostigmine as a reference standard against targets from different species, such as pure electric eel AChE, human serum AChE, and rat brain AChE. Among the compounds synthesized, compounds 5a, 5b, 5j showed good inhibition against AChE.

N-Substituted-2-butyl-5-chloro-3H-imidazole-4-carbaldehyde derivatives as anti-tumor agents against Ehrlich ascites tumor cells in vivo.

A new series of N-substituted 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde derivatives were synthesized by using the different bioactive heteroaralkyl halides with 2-butyl-4-chloro-1H-imidazole-5-carbaldehyde in presence of powdered potassium carbonate in DMF medium. These compounds were screened for their antitumor activity. Our results show that treatment of imidazole derivatives inhibit proliferation EAT cells, decreases the ascites volume and increases the survivability of the animals in vivo. These compounds also inhibited the cellular proliferation of HUVEC cells in vitro by MTT assay. Further, these compounds could induce apoptosis, which is evident by the nuclear condensation of imidazole derivatives treated EAT cells in vivo by the cytological analysis. We have identified that pyrrolidine substituted imidazole derivative as potent anti-tumor compound. These inhibitors could represent as promising candidates for anticancer therapies, where the formation of peritoneal malignant ascites is a major cause of morbidity and mortality.

Synthesis, characterization, antimicrobial and single crystal X-ray crystallographic studies of some new sulfonyl, 4-chloro phenoxy benzene and dibenzoazepine substituted benzamides.

A new class of benzamide derivatives 3a(I-VI) and 3b(I-VI), bearing different bioactive moieties were synthesized and evaluated for their efficacy as antimicrobials in vitro. Compounds 3bVI, 3aII, 3aV, 3bIII, 3aVI, 3bII showed significant antibacterial activity and 3bIII, 3bII, 3aIV, 3bV, 3bVI, 3aI exhibit significant antifungal activity. The title compounds are characterized by spectral and elemental analysis. Compounds 2-methoxy-N-[4-(thiazol-2-yl-sulfamoyl)-phenyl]-benzamide 3aII and 2-(2-(2-ethoxybenzoylamino) phenethyl)-N-(2-ethoxybenzoyl) benzenamine 3bV are characterized by the single crystal X-ray studies. Compound 3aII crystallizes in monoclinic space group P2(1) and 3bV in triclinic space group P-1. Compounds 3aII and 3bV exhibit both inter and intra molecular hydrogen bonding.

Synthesis and antimicrobial studies of a new series of 2-[4-[2-(5-ethylpyridin-2-yl)ethoxy]phenyl]-5-substituted-1,3,4-oxadiazoles.

A series of novel 2-[4-[2-(5-ethylpyridin-2-yl)ethoxy]phenyl]-5-substituted-1,3,4-oxadiazoles were synthesized by the oxidative cyclisation of hydrazones derived from 4-[2-(5-ethylpyridin-2-yl)ethoxy]benzaldehyde and aroylhydrazines using chloramine-T as oxidant. IR, NMR and elemental analysis characterized the newly synthesized compounds. The synthesized compounds were evaluated for their antimicrobial activity and were compared with standard drugs. The compounds demonstrated potent to weak antimicrobial activity. Out of the compounds studied, compounds 8c and 8d showed significant inhibition. Compounds 8b, 8f, 8k and 8e showed moderate activity. The minimum inhibitory concentration of the compounds was in the range of 8-26 microg ml(-1) against bacteria and 8-24 microg ml(-1) against fungi. The title compounds represent a novel class of potent antimicrobial agents.

Microwave-assisted synthesis of N-alkylated benzotriazole derivatives: antimicrobial studies.

Synthesis and characterization of N-alkylated benzotriazole derivatives 2(a-g) bearing pharmaceutically important bioactive substituents and their antimicrobial studies in vitro are described. The syntheses of the compounds were achieved by N-alkylation of the benzotriazole with different bioactive alkyl halides in presence of powdered K2CO3 in DMF solution and by microwave irradiation method with good yield compared to conventional method. The crystal structure analysis shows that compound 4'-benzotriazol-1-yl-methyl-biphenyl-2-carbonitrile 2a crystallizes in the space group P1 with cell parameters a = 8.526 (3) A, b = 12.706 (3) A, c = 7.966 (2) A, alpha = 100.89 (2) degrees , beta = 101.63 (3) degrees , gamma = 102.20(2) degrees, Volume = 801.7(4) A degrees , Z = 2 and the final R factor is 0.0559 for 6130 reflections with 218 parameters and zero restraint. This structure exhibits intermolecular hydrogen bonding. Compounds 2e, 2a showed significant antimicrobial activity.

Trityl losartan.

The title compound (systematic name: [2-butyl-4-chloro-1-[2'-(2-trityl-2H-tetrazol-5-yl)biphenyl-4-ylmethyl]-1H-imidazol-5-yl]methanol), C(41)H(37)ClN(6)O, crystallizes in the centrosymmetric space group P-1 with two independent molecules in the asymmetric unit. These molecules differ significantly only in the relative orientations of the rings in the biphenylyltetrazole moieties. One of the molecules shows disorder for three C atoms in the n-butyl group. Hydrogen bonds link the molecules in an infinite chain along the a axis.