Diversity analysis of selected rice landraces from West Bengal and their linked molecular markers for salinity tolerance

Study of genetic diversity in crop plants is essential for the selection of appropriate germplasm for crop improvement. As salinity posses a serious environmental challenge to rice production globally and especially in India, it is imperative that the study of large collections of germplasms be undertaken to search for salt tolerant stocks. In the present study, 64 indica germplasms were collected from different agro-climatic zones of West Bengal, India, from the Himalayan foothills in the northern part down to the southern saline belt of the state keeping in view the soil characteristics and other edaphic factors prevailing in the region. Salt tolerance parameters were used to screen the large set of germplasms in terms of root-shoot length, fresh-dry weight, chlorophyll content, Na+/K+ ratio and germination potential in presence of salt. Standard evaluation score or SES was calculated to find out tolerant to sensitive cultivar. Twenty-one SSR markers, some associated with the Saltol QTL and others being candidate gene based SSR (cgSSR) were used to study the polymorphism of collected germplasm. A wide diversity was detected among the collected germplasms at the phenotypic as well as molecular level. Of the 21 SSR markers, 15 markers were found to be polymorphic with 88 alleles. Based on phenotypic and biochemical results, 21 genotypes were identified as salinity tolerant, whereas 40 genotypes turned out to be salt susceptible. The present study shows that apart from the established salt tolerant lines, several other landraces like Bonkanta, Morisal, Ghiosh, Patni may be the source of salt tolerant donor in future breeding programs.     

Design,Synthesis, and Biological Evaluation of 2‐(2‐Bromo‐3‐nitrophenyl)‐5‐phenyl‐1,3,4‐oxadiazole Derivatives as Possible Anti‐Breast Cancer Agents

Breast Cancer (BCa) is the most often diagnosed cancer among women who were in the late 1940’s. Breast cancer growth is largely dependent on the expression of estrogen and progesterone receptor. Breast cancer cells may have one, both, or none of these receptors. The treatment for breast cancer may involve surgery, hormonal therapy (Tamoxifen, an aromatase inhibitor, etc.) and oral chemotherapeutic drugs. The molecular docking technique reported the findings on the potential binding modes of the 2‐(2‐bromo‐3‐nitrophenyl)‐5‐phenyl‐1,3,4‐oxadiazole derivatives with the estrogen receptor (PDB ID: 3ERT). The 1,3,4‐oxadiazole derivatives 4a – 4j have been synthesized and described by spectroscopic method. 2‐(2‐Bromo‐6‐nitrophenyl)‐5‐(4‐bromophenyl)‐1,3,4‐oxadiazole ( 4c ) was reconfirmed by single‐crystal XRD. All the compounds have been tested in combination with generic Imatinib pharmaceutical drug against breast cancer cell lines isolated from Caucasian woman MCF‐7, MDA‐MB‐453 and MCF‐10A non‐cancer cell lines. The compounds with the methoxy (in 4c ) and methyl (in 4j ) substitution were shown to have significant cytotoxicity, with 4c showing dose‐dependent activation and decreased cell viability. The mechanism of action was reported by induced apoptosis and tested by a DNA enzyme inhibitor experiment (ELISA) for Methyl Transferase. Molecular dynamics simulations were made for hit molecule 4c to study the stability and interaction of the protein?ligand complex. The toxicity properties of ADME were calculated for all the compounds. All these results provide essential information for further clinical trials.     

Synthesis and in vitro anti-mycobacterial activity of 5-substituted pyrimidine nucleosides

Mycobacterium tuberculosis and Mycobacterium avium infections cause the two most important mycobacterioses, leading to increased mortality in patients with AIDS. Various 5-substituted 2′-deoxyuridines, uridines, 2′-O-methyluridine, 2′-ribofluoro-2′-deoxyuridines, 3′-substituted-2′,3′-dideoxy uridines, 2′,3′-dideoxyuridines, and 2′,3′-didehydro-2′,3′-dideoxyuridines were synthesized and evaluated for their in vitro inhibitory activity against M. bovis and M. avium. 5-(C-1 Substituted)-2′-deoxyuridine derivatives emerged as potent inhibitors of M. avium (MIC₉₀ = 1–5 μg/mL range). The nature of C-5 substituents in the 2′-deoxyuridine series appeared to be a determinant of anti-mycobacterial activity. This new class of inhibitors could serve as useful compounds for the design and study of new anti-tuberculosis agents.     

Asymmetric synthesis of (S)-ethyl-4-chloro-3-hydroxybutanoate using Candida parapsilosis ATCC 7330

Asymmetric reduction of ethyl-4-chloro-3-oxobutanoate to (S)-ethyl-4-chloro-3-hydroxybutanoate in aqueous medium by resting cells of Candida parapsilosis ATCC 7330 was optimized. The influence of culture parameters (inoculum size, inoculum age and biocatalyst harvest time) and reaction parameters (co-substrate, resting cell, pH and substrate concentrations) on the asymmetric reduction were studied. It was found that these parameters significantly influenced the rate of the asymmetric reduction. Under the optimum conditions, the final concentration of (S)-ethyl-4-chloro-3-hydroxybutanoate, enantiomeric excess and the isolated yield of (S)-ethyl-4-chloro-3-hydroxybutanoate were 1.38 M (230 g/l), >99 and 95%, respectively. The space time yield was 115 mmol/lh, which is significantly higher than other whole cell biocatalysts reported so far.     

Expression of hemopoietic histocompatibility antigens on H-2-loss variants of F1 hybrid lymphoma cells: evidence consistent with trans gene regulation

H-2 heterozygous marrow stem cells, lymphoid progenitor cells, and leukemia/lymphoma cells do not express hemopoietic or hybrid histocompatibility (Hh) antigens, which are important transplantation antigens recognized during the rejection of normal or neoplastic hemopoietic cells. The Hh-1b determinant of the H-2b haplotype maps to the D region of H-2. We have tested the hypothesis that gene(s) at or near H-2D of the H-2d haplotype down-regulate the expression of Hh-1b in the trans configuration. We used Abelson leukemia virus-transformed pre-B lymphoma cells (ACCb) of BALB/c X BALB.B (H-2d X H-2b) origin, as well as variant lines of ACCb, which were selected for resistance to monoclonal anti-H-2 antibodies plus complement. B6D2F1 (H-2b X H-2d), C3B6F1 (H-2k X H-2b), or B6 (H-2b) mice were infused with inocula of 5 X 10(6) B6 bone marrow cells (BMC). Proliferation of donor-derived marrow cells was judged in terms of DNA synthesis by measuring the splenic incorporation of 5-iodo(125I)-2'-deoxyuridine (IUdR) 5 days after cell transfer. B6 BMC grew much better in B6 than in F1 hybrid host mice, an expression of "hybrid resistance". As observed previously, the injection of EL-4 (H-2b, Hh-1b) tumor cells prior to infusion of B6 (H-2b, Hh-1b) BMC enhanced the growth of B6 BMC in F1 hybrid mice. Therefore, this in vivo "cold target cell competition" type of assay can be used to detect the expression of Hh-1b antigens. Unlike EL-4 (H-2b) cells, hybrid resistance was not affected by prior infusion of (H-2b X H-2d) heterozygous ACCb cells. In contrast, three ACCb variant cell lines, H-2d-, Ld-Dd-, and Dd-, enhanced the growth of B6 BMC in F1 hosts. The ACCb H-2b- cell line did not affect hybrid resistance to B6 BMC. The loss of gene expression on the H-2d chromosome at or very near the H-2Dd locus is correlated with the appearance Hh-1b, as determined by the in vivo cold target competition assay. These results support the hypothesis that heterozygous cells possess trans-acting, dominant, down-regulatory genes mapping near H-2D that control the Hh-1 phenotype of lymphoid tumor cells.     

Digitalis-like pregnanes. Cardiac and renal effects of a glycoside of 14 beta-hydroxyprogesterone

The synthesis of the glucoside, 3 beta-[(beta-D-glucopyranosyl)oxy]-14-hydroxy-14 beta-pregn-4-en-20-one, a 14 beta-hydroxyprogesterone glucoside (14 beta-OHP-glu), is described. This compound has an IC50 of 1 microM in a [3H]ouabain binding assay, and is about 10 times more potent than the aglycone. Like 14 beta-hydroxyprogesterone, the glucoside enhances contractility of isolated cardiac muscle. 14 beta-OHP-glu or ouabain, when infused at comparable doses into the renal artery of the anesthetized rat, markedly increases urine volume. Whereas ouabain significantly enhances urinary potassium excretion with little or no effect on sodium excretion, 14 beta-OHP-glu promotes a marked natriuresis with no significant effect on potassium excretion.     

The dynamics of quadrupedal locomotion

This paper presents a dynamical analysis of quadrupedal locomotion, with specific reference to an adult Nubian goat. Measurements of ground reaction forces and limb motion are used to assess variations in intersegmental forces, joint moments, and instantaneous power for three discernible gaits: walking, running, and jumping. In each case, inertial effects of the torso are shown to dominate to the extent that lower-extremity contributions may be considered negligible. Footforces generated by the forelimbs exceed those exerted by the hindlimbs; and, in general, ground reactions increase with speed. The shoulder and hip dominate mechanical energy production during walking, while the knee plays a more significant role in running. In both cases, however, the elbow absorbs energy, and by so doing functions primarily as a damping (control) element. As opposed to either walking or running, jumping requires total horizontal retardation of the body's center of mass. In this instance, generating the necessary vertical thrust amounts to energy absorption at all joints of the lower extremities.     

Chickpea seed proteins: Modification during germination

Changes in the proteins of chickpea during a 12-day germination period are reported using techniques of gel filtration, DEAE-cellulose chromatography, polyacrylamide gel (PAG) electrophoresis and ultracentrifugation. In the ultracentrifuge, the total proteins of dormant seeds resolve into 3 components which have the sedimentation coefficients of 2.2 S, 6.9 S and 10.3 S respectively. On germination, the presence of fractions of lower sedimentation coefficient indicates possible degradation of these components; in the early stages, the degradation rate of the 7 S fraction is higher, while the 10 S fraction is broken down faster in the later stages. Gel filtration experiments indicate the possibility of degradation of high polymer into intermediary products. Increase in the relative mobility of protein components on PAG and elution constant on DEAE-cellulose chromatographs indicates an increase in the net negative charge of the protein fractions. The accumulation of subunits of the proteins is negligible during the germination period.