An ecofriendly synthesis and DNA binding interaction study of some pyrazolo [1,5-a]pyrimidines derivatives

The DNA molecule is a target for plethora of anticancer and antiviral drugs that forms covalent and non-covalent adducts with major or minor groove of DNA. In present study we synthesized series of novel Pyrazolo [1,5-a]pyrimidine derivatives. The newly synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, and mass spectral data. The selected compounds were studied for interaction with Calf thymus DNA (CT-DNA) using electronic spectra, viscosity measurement and thermal denaturation studies. Further, molecular interactions were revealed for compound IIIa and IVa by computational methodologies. The preferred mode of ligand binding with double helical DNA as well as preferable DNA groove were explored by molecular docking in different DNA models.     

InCl3-catalysed synthesis of 2-aryl quinazolin-4(3H)-ones and 5-aryl pyrazolo[4,3-d]pyrimidin-7(6H)-ones and their evaluation as potential anticancer agents

A convenient and practical methodology for the synthesis of 2-aryl quinazolin-4(3H)-ones by the condensation of o-aminobenzamides with aromatic aldehydes under mild conditions using catalytic InCl(3) with good yields and high selectivities. This method has been extended for the synthesis of 5-aryl pyrazolo[4,3-d]pyrimidin-7(6H)-ones which have potential applications in medicinal chemistry. Many of these compounds were evaluated for their anti-proliferative properties in vitro against four cancer cell lines and several compounds were found to be active. Further in vitro studies indicated that inhibition of sirtuins could be the possible mechanism of action of these molecules.     

Mycobacterium indicus pranii (Mw) re-establishes host protective immune response in Leishmania donovani infected macrophages: critical role of IL-12

Leishmania donovani, a protozoan parasite, causes a strong immunosuppression in a susceptible host and inflicts the fatal disease visceral leishmaniasis. Relatively high toxicity, low therapeutic index, and failure in reinstating host-protective anti-leishmanial immune responses have made anti-leishmanial drugs patient non-compliant and an immuno-modulatory treatment a necessity. Therefore, we have tested the anti-leishmanial efficacy of a combination of a novel immunomodulator, Mycobacterium indicus pranii (Mw), and an anti-leishmanial drug, Amphotericin B (AmpB). We observe that Mw alone or with a suboptimal dose of AmpB offers significant protection against L. donovani infection by activating the macrophages. Our experiments examining the anti-leishmanial activity of Mw alone or with AmpB also indicate a p38MAPK and ERK-1/2 regulated pro-inflammatory responses. The Mw-AmpB combination induced nitric oxide production, restored Th1 response, and significantly reduced parasite burden in wild type macrophages but not in IL-12-deficient macrophages indicating a pivotal role for IL-12 in the induction of host-protection by Mw and AmpB treatments. In addition, we observed that Mw alone or in combination with suboptimal dose of AmpB render protection against L. donovani infection in susceptible BALB/c mice. However, these treatments failed to render protection in IL-12-deficient mice in vivo which added further support that IL-12 played a central role in this chemo immunotherapeutic approach. Thus, we demonstrate a novel chemo-immunotherapeutic approach- Mw and AmpB crosstalk eliminating the parasite-induced immunosuppression and inducing collateral host-protective effects.     

In silico modeling and docking studies of Soap Nut Trypsin Inhibitor

Soap nut trypsin inhibitor (SNTI), an inhibitory protein was isolated and purified from the seeds of Sapindus trifoliatus by ammonium sulphate precipitation followed by ion-exchange and gel filtration chromatographic techniques and was found to be homogenous by PAGE. Using advanced proteomic techniques like MALDI-TOF the inhibitor was sequenced and analyzed using MASCOT software. A refined 3D model of the structure was predicted by in silico technique like homology modeling. The docked interactions between the predicted structure of SNTI and bovine trypsin were studied using ClusPro 2.0. Further docking results indicate that residues within the receptor binding domain include N145, R241, P242, L243, R244, R249, E266 and R275 respectively which play a key role in protein–protein interaction between SNTI and 3MFJ (bovine trypsin). SNTI was also known to exhibit potent anti-fungal activity against dandruff causing fungi. This study provides an insight into the structure of SNTI and also gives an idea about potential sites responsible for inhibitory action that could further be substantiated by experimental investigations.     

CYP1A1 genotypes and haplotypes and risk of oral cancer: A case-control study in South Indians

The CYP1A1 gene encodes for the enzyme, aryl hydrocarbon hydroxylase, which is involved in the biotransformation of various aromatic tobacco precarcinogens. In the present study, the association between CYP1A1 gene polymorphisms (IVS1-728G > A, Thr461Asn and Ile462Val), and the risk of oral cancer, was examined among 157 patients with oral cancer and 132 age-matched controls, in a south Indian population. The strength of the association between CYP1A1 variants and oral cancer was estimated by logistic regression. It was found that Thr461Asn was not polymorphic. Both IVS1-728G > A and Ile462Val frequencies were consistent with Hardy-Weinberg equilibrium in the control group. There were no significant differences in genotype or haplotype frequencies between controls and cases with oral cancer. Hence, CYP1A1 SNPs can be considered as not being associated with oral cancer at either the genotype or haplotype levels in the population studied.     

Exposure to heavy ion radiation induces persistent oxidative stress in mouse intestine

Ionizing radiation-induced oxidative stress is attributed to generation of reactive oxygen species (ROS) due to radiolysis of water molecules and is short lived. Persistent oxidative stress has also been observed after radiation exposure and is implicated in the late effects of radiation. The goal of this study was to determine if long-term oxidative stress in freshly isolated mouse intestinal epithelial cells (IEC) is dependent on radiation quality at a dose relevant to fractionated radiotherapy. Mice (C57BL/6J; 6 to 8 weeks; female) were irradiated with 2 Gy of γ-rays, a low-linear energy transfer (LET) radiation, and intestinal tissues and IEC were collected 1 year after radiation exposure. Intracellular ROS, mitochondrial function, and antioxidant activity in IEC were studied by flow cytometry and biochemical assays. Oxidative DNA damage, cell death, and mitogenic activity in IEC were assessed by immunohistochemistry. Effects of γ radiation were compared to (56)Fe radiation (iso-toxic dose: 1.6 Gy; energy: 1000 MeV/nucleon; LET: 148 keV/μm), we used as representative of high-LET radiation, since it's one of the important sources of high Z and high energy (HZE) radiation in cosmic rays. Radiation quality affected the level of persistent oxidative stress with higher elevation of intracellular ROS and mitochondrial superoxide in high-LET (56)Fe radiation compared to unirradiated controls and γ radiation. NADPH oxidase activity, mitochondrial membrane damage, and loss of mitochondrial membrane potential were greater in (56)Fe-irradiated mice. Compared to γ radiation oxidative DNA damage was higher, cell death ratio was unchanged, and mitotic activity was increased after (56)Fe radiation. Taken together our results indicate that long-term functional dysregulation of mitochondria and increased NADPH oxidase activity are major contributing factors towards heavy ion radiation-induced persistent oxidative stress in IEC with potential for neoplastic transformation.     

Modeling and experimental analyses reveals signaling plasticity in a bi-modular assembly of CD40 receptor activated kinases

Depending on the strength of signal dose, CD40 receptor (CD40) controls ERK-1/2 and p38MAPK activation. At low signal dose, ERK-1/2 is maximally phosphorylated but p38MAPK is minimally phosphorylated; as the signal dose increases, ERK-1/2 phosphorylation is reduced whereas p38MAPK phosphorylation is reciprocally enhanced. The mechanism of reciprocal activation of these two MAPKs remains un-elucidated. Here, our computational model, coupled to experimental perturbations, shows that the observed reciprocity is a system-level behavior of an assembly of kinases arranged in two modules. Experimental perturbations with kinase inhibitors suggest that a minimum of two trans-modular negative feedback loops are required to reproduce the experimentally observed reciprocity. The bi-modular architecture of the signaling pathways endows the system with an inherent plasticity which is further expressed in the skewing of the CD40-induced productions of IL-10 and IL-12, the respective anti-inflammatory and pro-inflammatory cytokines. Targeting the plasticity of CD40 signaling significantly reduces Leishmania major infection in a susceptible mouse strain. Thus, for the first time, using CD40 signaling as a model, we show how a bi-modular assembly of kinases imposes reciprocity to a receptor signaling. The findings unravel that the signalling plasticity is inherent to a reciprocal system and that the principle can be used for designing a therapy.     

MycoProtease-DB: Useful resource for Mycobacterium tuberculosis complex and nontuberculous mycobacterial proteases

MycoProtease-DB is an online MS SQL and CGI-PERL driven relational database that domiciles protease information of Mycobacterium tuberculosis (MTB) complex and Nontuberculous Mycobacteria (NTM), whose complete genome sequence is available. Our effort is to provide comprehensive information on proteases of 5 strains of Mycobacterium tuberculosis (H₃₇Rv, H₃₇Ra, CDC1551, F11 and KZN 1435), 3 strains of Mycobacterium bovis (AF2122/97, BCG Pasteur 1173P2 and BCG Tokyo 172) and 4 strains of NTM (Mycobacterium avium 104, Mycobacterium smegmatis MC2 155, Mycobacterium avium paratuberculosis K-10 and Nocardia farcinica IFM 10152) at gene, protein and structural level. MycoProtease-DB currently hosts 1324 proteases, which include 906 proteases from MTB complex with 237distinct proteases & 418 from NTM with 404 distinct proteases. Flexible database design and easy expandability & retrieval of information are the main features of MycoProtease-DB. All the data were validated with various online resources and published literatures for reliable serving as comprehensive resources of various Mycobacterial proteases.

Availability

The Database is publicly available at http://www.bicjbtdrc-mgims.in/MycoProtease-DB/     

Blastobotrys serpentis sp. nov., isolated from the intestine of a Trinket snake (Elaphe sp., Colubridae)

Asporogenus yeast strains W113AT and W113B were isolated from the intestine of a dead Trinket snake. The two isolates showed 100% sequence similarity in the D1/D2 domain of the large-subunit (LSU) rRNA gene, internal transcribed spacer (ITS) 1-5.8S rRNA gene-ITS2 region and mitochondrial small-subunit rRNA gene and the cytochrome oxidase II gene sequence and also showed similar phenotypic characteristics. The nearest phylogenetic neighbors of W113AT and W113B based on the sequence of the D1/D2 domain of the LSU rRNA gene were Blastobotrys chiropterorum NRRL Y-17017T and Blastobotrys terrestris NRRL Y-17704T with about 98% similarity. The close affiliation of W113AT and W113B with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T was also evident from the high similarity observed in the nucleotide sequences of the mitochondrial small subunit rRNA (96-97.8%) and the cytochrome oxidase II (95.5-95.6%) genes. In the neighbor-joining phylogenetic trees constructed based on the D1/D2 domain or cytochrome oxidase gene, the isolates clustered with the above-mentioned species. However, the isolates showed a number of differences in their phenotypic properties with B. chiropterorum NRRL Y-17017T and B. terrestris NRRL Y-17704T and hence are regarded as representing a novel member of the genus Blastobotrys, for which the name Blastobotrys serpentis sp. nov. is proposed.