Liquid chromatographic separation of darunavir enantiomers on coated and immobilized amylose tris(3, 5-dimethylphenylcarbamate) chiral stationary phases

Liquid chromatographic separation of darunavir enantiomers on covalently bonded and physically adsorbed polysaccharide chiral stationary phases was studied at different temperatures. The separations were accomplished under normal-phase conditions by using different combinations of hexane, organic modifiers (2-propanol, 1-propanol and ethanol), and diethylamine as mobile phase solvents. The effect of organic modifiers and the column temperature on retention, separation, and resolution was investigated. The observed differences were explained in terms of the coated and immobilized nature of the two columns. Van't Hoff plots (ln k' vs. 1/T, ln α vs. 1/T) and apparent thermodynamic parameters were derived to understand the effect of temperature on separation.     

A ten-residue domain (Y11-A20) in the NH2-terminus modulates membrane association of annexin A7

Annexin A7 (synexin, annexin VII) is postulated to promote membrane fusion during surfactant secretion in alveolar type II cells and catecholamine secretion in adrenal chromaffin cells. Recently, we demonstrated that the 1-29 residues in the NH(2)-terminus could, possibly by interaction with the COOH-terminus, influence the Ca(2+)-dependent membrane binding, aggregation, and fusion properties of annexin A7 (A7). In this study, we further investigated this 29-residue domain by evaluating several deletion and point mutations for membrane-associated functions of A7. In comparison to A7, the mutants lacking 1-29 residues (A7Delta(1-29)) or 1-21 residues (A7Delta(1-21)), but not those lacking 1-10 residues (A7Delta(1-10)) or 21-29 residues (A7Delta(21-29)), showed diminished membrane binding. Segmental deletion of 10-20 residues (A7Delta(10-20)) also decreased the protein binding to membranes. The Ca(2+)-dependent membrane aggregation of PLV with A7Delta(1-29) was maximally diminished but less so with A7Delta(10-20) or A7Delta(1-21) in comparison to that with A7. However, phospholipid vesicle (PVL) aggregation was unaffected with A7Delta(1-10) or A7Delta(21-29). The Ca(2+)-dependent membrane fusion of PLV was also diminished with A7Delta(10-20) and A7Delta(1-29), but not with A7Delta(1-10). Since the mode of annexin A7 association and function with biological membranes could be different, we also evaluated these proteins for functional changes with isolated lung lamellar bodies. In comparison to A7, the binding to lamellar bodies was diminished for A7Delta(1-29) and A7Delta(1-21) but not for A7Delta(1-10). The Ca(2+)-dependent fusion of isolated lamellar bodies with PLV was also diminished with A7Delta(1-29), but not with A7Delta(10-20) or A7Delta(1-21). Taken together, our studies suggest that the 10-residue domain (Y(11)-A(20)) in the NH(2)-terminus modifies the phospholipid binding and aggregation properties of annexin A7. For binding and fusion of biological membranes, the 10-29-residue domain may be required although the annexin A7 properties are primarily modulated through the Y(11)-A(20) domain.     

Techniques for integrating ‐omics data

The challenge for -omics research is to tackle the problem of fragmentation of knowledge by integrating several sources of heterogeneous information into a coherent entity. It is widely recognized that successful data integration is one of the keys to improve productivity for stored data. Through proper data integration tools and algorithms, researchers may correlate relationships that enable them to make better and faster decisions. The need for data integration is essential for present ‐omics community, because ‐omics data is currently spread world wide in wide variety of formats. These formats can be integrated and migrated across platforms through different techniques and one of the important techniques often used is XML. XML is used to provide a document markup language that is easier to learn, retrieve, store and transmit. It is semantically richer than HTML. Here, we describe bio warehousing, database federation, controlled vocabularies and highlighting the XML application to store, migrate and validate -omics data.     

Polyelectrolyte complexes of gum kondagogu and chitosan,as diclofenac carriers

Polyelectrolyte complexes (PEC) of gum kondagogu (GKG) and chitosan were prepared by mixing polymeric solutions of different concentrations (0.02–0.18% w/v). The complex formed were loaded with diclofenac sodium, and the release of the drug was measured in vitro and in vivo, along with the measurement of particle size, zeta potential, complex formation, flow properties, and loading efficiency. Maximum yield of PEC was observed at gum kondagogu concentrations above 80%. The PEC showed lower release of diclofenac sodium in 0.1 N HCl as compared to phosphate buffer (pH 6.8). Increasing the concentration of gum kondagogu in PEC led to an increase in drug release. However, PEC 1:3 (gum kondagogu: chitosan) with higher concentration of chitosan showed 98% release with in 4.5 h, owing to the fact that chitosan has a higher degree of swelling in acidic medium. PEC 5:1 and 3:1 showed a 5.3- and 5.8-fold increase in relative bioavailability compared to the free drug when administered orally to the rats.     

Immunomodulation of macrophages by radio-detoxified lipopolysaccharide of Salmonella typhimurium

Lipopolysaccharide (LPS) and ratio-detoxified LPS (Rd-LPS) from Salmonella typhimurium were analysed for their ability to stimulate murine peritoneal exudate cells (PEC) and macrophages. Rd-LPS induced much more inflammatory response as compared to LPS. PEC numbers/mouse obtained were significantly higher (3-fold) in response to Rd-LPS than LPS. The haemorrhage was induced in mice by LPS but not by Rd-LPS. Activation of macrophages in vivo by Rd-LPS was significantly higher as compared to LPS. This was evident from the increase levels of their lysosomal enzymes and cytokines. Rd-LPS induced 10-fold increase in acid phosphatase contents of macrophages as compared to controls while only 7-fold increase was obtained with LPS. Arylsulfatase and beta-glucuronidase increased by about 2-fold by Rd-LPS and LPS. Macrophages incubated with Rd-LPS in vitro showed 16-fold and 20-fold increase in the cell associated levels of arylsulfatase and beta-glucuronidase respectively as compared to unstimulated cells. On the other hand, only 6-fold increase was observed in response to LPS in the levels of both the enzymes. TNF-[symbol: see text] and IL-1 secreted by macrophages increased considerably in response to Rd-LPS as compared to those released by LPS. Rd-LPS, thus seems to be a better immunomodulator than untreated LPS.     

D2-dopamine receptor and alpha2-adrenoreceptor-mediated analgesic response of quercetin

Quercetin, a bioflavonoid (100-300 mg/kg) produced dose dependent increase in tail-flick latency, the analgesic effect being sensitive to reversal by naloxone (1 mg/kg). Prior treatment with haloperidol (1 mg/kg), D1/D2 receptor antagonist haloperidol, sulpiride (50 mg/kg), a selective D2 receptor antagonist, yohimbine (5 mg/kg), a alpha2-adrenoreceptor antagonist but not by SCH 23390 a, selective D1 receptor antagonist blocked this response. Apomorphine (1 mg/kg) a mixed D1/D2 dopamine receptor agonist, and quinpirole (0.5 mg/kg), a selective D2 receptor agonist also produced antinociception, that was reversed by haloperidol (1 mg/kg), sulpiride (50 mg/kg), but not by yohimbine (5 mg/kg). The antinociceptive action of quercetin (200 mg/kg) was potentiated by D2 agonist quinpirole (0.2 mg/kg). Dopamine D1 receptor agonist SKF38393 (10 and 15 mg/kg) failed to alter the antinociceptive effect of quercetin (200 mg/kg). Quercetin (200 mg/kg) reversed reserpine (2 mg/kg-4 hr) induced hyperalgesia, which was reversed by sulpiride but not by yohimbine. Thus, a role of dopamine D2 and alpha2-adrenoreceptors is postulated in the antinociceptive action of quercetin.     

Hydrolysis of fenamiphos and its oxidation products by a soil bacterium in pure culture,soil and water

A bacterium, identified as Brevibacterium sp. MM1, readily hydrolysed fenamiphos, a widely used organophosphorus insecticide and its toxic oxides (fenamiphos sulfoxide, fenamiphos sulfone), which all contain a common P-O-C bond, in a mineral salts medium. The bacterium also hydrolysed fenamiphos and its oxides in soil and groundwater. Interestingly, fenamiphos phenol, fenamiphos sulfoxide phenol and fenamiphos sulfone phenol, formed during bacterial hydrolysis of fenamiphos and its oxides, persisted in the mineral salts medium, but were transitory in soil and groundwater due to their further metabolism by indigenous micro-organisms. The cell-free preparation (crude enzyme) of this bacterium was very effective in hydrolysing fenamiphos. This is the first report on exceptionally rapid hydrolysis of fenamiphos by a bacterium in pure cultures, soil and groundwater.