Triterpenoids and coumarins from the leaves of calophyllum cordato-oblongum

The hot light petrol extractives of the leaves of Calophyllum cordato-oblongum gave D:A-friedo-oleanan-3-one, 28-hydroxy-D:A-friedo-oleanan-3-one (canophyllol) and three new coumarins: cordatolides A and B and oblongulide.     

Genetic tranformation of cotyledon explants of cowpea (Vigna unguiculata L. Walp) using Agrobacterium tumefaciens

Mature de-embryonated cotyledons with intact proximal end of Vigna unguiculata were cultured on B5 basal medium containing varying concentrations of BAP. Thirty-six percent of the explants produced shoots on B5 medium supplemented with 8× 10^–6 M BAP. Cotyledon explants were pre-incubated for 24 h, inoculated with A. tumefaciens pUCD2614 carrying pUCD2340, co-cultivated for 48 h and transferred to hygromycin-B (25 mg/l) containing shoot induction medium. Approximately 15–19% of the explants produced shoots on the selection medium. The elongated shoots were subsequently rooted on B5 basal medium containing hygromycin. The transgenic plants were later established in pots. The presence of hpt gene in the transgenic plants was confirmed by Southern blot hybridization.Abbreviations BAP 6-Benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - hpt hygromycin phosphotransferase - IAA Indole-3-acetic acid - NAA 1-naphthaleneacetic acid     

The substrate for cholesterol 7alpha-hydroxylase.

The rates of incorporation of (14C) cholesterol into cholesteryl esters and 5-cholestene-3beta,7alpha-diol (7alpha-hydroxycholesterol) by rat liver microsomes, measured under conditions in which esterification and 7alpha-hydroxylation are varied independently, indicated that cholesterol is the substrate for cholesterol 7alpha-hydroxylase. The specific activities of cholesteryl esters and 7alpha-hydroxycholeste ol in incubations of microsomes labelled with (14C)cholesterol in vitro or in vivo suggest that 7alpha-hydroxycholesterol and esterified cholesterol are not derived from the same pool of free cholesterol.     

The glycoprotein toxin of Bacillus thuringiensis subsp. israelensis indicates a lectinlike receptor in the larval mosquito gut

The mosquito-active protein crystals produced by Bacillus thuringiensis subsp. israelensis contain covalently attached aminosugars which are critical for their larvicidal activity. The 50% lethal concentrations toward Aedes aegypti larvae were increased up to 10-fold by mild periodate treatment, up to 40-fold by forming the protein crystals in the presence of tunicamycin, and up to 7-fold by the presence during the mosquito bioassays of N-acetylglucosamine or its trimer, triacetylchitotriose. Periodate-treated crystals and crystals formed in the presence of tunicamycin had greatly reduced binding capacities for wheat germ agglutinin, an N-acetylglucosamine-specific lectin. These results suggest that the B. thuringiensis subsp. israelensis glycoprotein toxin binds to a lectinlike receptor in the larval mosquito gut. Furthermore, the distinct lectin-binding patterns exhibited by diptera-active versus lepidoptera-active B. thuringiensis crystals suggest that host specificity for the microbial insecticides is determined, in part, by the carbohydrate portion of their glycoprotein crystals.     

1,2(3)-Tetrahydro-3,3′-biplumbagin: A naphthalenone and other constituents from Plumbago zeylanica

The isolation of plumbagin, droserone, isoshinanolone and a new naphthalenone, 1,2(3)-tetrahydro-3,3′-biplumbagin is reported from the phenolic fract     

Allozyme diversity and systematics inAnnonaceae—a pilot project

Five species ofAnnona and one species fromArtabotrys, Cananga, Polyalthia, andRollinia were investigated in regard to 11 different allozyme loci. Preliminary studies on small population samples ofAnnona suggest genetic uniformity in three species and variability within and between populations in two other species. The allotetraploid origin ofA. glabra is clearly shown by its hybrid enzyme bands. The genetic distance between fiveAnnona species partly corresponds with their morphological relationships; onlyA. muricata appears more separated than is suggested by morphology. A comparison of the five genera demonstrates close relationship betweenAnnona andRollinia. Two enzyme loci are identical within all taxa investigated and possibly may serve as a genetic marker for the family.     

Identification of novel sweet protein for nutritional applications

The prevalence of obesity and diabetes has increased exponentially in recent years around the globe, especially in India. Sweet proteins have the potential to substitute the sugars, by acting as natural, good and low calorie sweeteners. They also do not trigger a demand for insulin in diabetic patients unlike sucrose. In humans, the sweet taste perception is mainly due to taste-specific G protein-coupled heterodimeric receptors T1R2-T1R3. These receptors recognize diverse natural and synthetic sweeteners such as monelin, brazzein, thaumatin, curculin, mabinlin, miraculin and pentadin. Structural modeling of new sweetener proteins will be a great leap in further advancement of knowledge and their utility as sweeteners. We have explored the fingerprints of sweetness by studying the aminoacid composition and structure properties of the above proteins. The structural analysis of monellin revealed that the individual A or B chains of monellin are not contributing to its sweetness. However, the native conformation and ionic interaction between AspB7 of monellin with active site of T1R2-T1R3 receptor, along with hydrogen bonding stability of IleB6 and IleB8 are responsible for the sweet taste. Based on structural similarity search, we found a new hypothetical protein from Shewanella loihica, which has the presence of Asp(32) with adjacent isoleucine residues. Further, we examined the lead protein by two-step docking for the study of interaction of functionally conserved residues with receptors. The identified protein showed similar ionic and hydrophobic interactions with monelin. This gives a promising opportunity to explore this protein for potential health application in the low calorie sweetener industry viz., soft drinks, snacks, food, chocolate industries etc.     

Modeling of Neuropeptide Receptors Y1, Y4, Y5, and Docking Studies with Neuropeptide Antagonist Analogues: Implications for Selectivity

Abstract Neuropeptide Y (NPY), receptors belong to the G-protein coupled receptor superfamily. NPY mediates several physiological responses, such as blood pressure, food intake, sedation. These actions of NPY are mediated by six receptor subtypes denoted as Y(1)-Y(5) and y(6). Modeling of receptor subtypes and binding site identification is an important step in developing new therapeutic agents. We have attempted to model the three NPY receptor types, Y1, Y4, and Y5 using homology modeling and threading methods. The models are consistent with previously reported experimental evidence. To understand the interaction and selectivity of NPY analogues with different neuropeptide receptors, docking studies of two neuropeptide analogues (BVD10 and BVD15) with receptors Y1 and Y4 were carried out. Results of the docking studies indicated that the interaction of ligands BVD10 and BVD15 with Y1 and Y4 receptors are different. These results were evaluated for selectivity of peptide analogues BVD10 and BVD15 towards the receptors.     

The proximal proteome of 17 SARS-CoV-2 proteins links to disrupted antiviral signaling and host translation

Viral proteins localize within subcellular compartments to subvert host machinery and promote pathogenesis. To study SARS-CoV-2 biology, we generated an atlas of 2422 human proteins vicinal to 17 SARS-CoV-2 viral proteins using proximity proteomics. This identified viral proteins at specific intracellular locations, such as association of accessary proteins with intracellular membranes, and projected SARS-CoV-2 impacts on innate immune signaling, ER-Golgi transport, and protein translation. It identified viral protein adjacency to specific host proteins whose regulatory variants are linked to COVID-19 severity, including the TRIM4 interferon signaling regulator which was found proximal to the SARS-CoV-2 M protein. Viral NSP1 protein adjacency to the EIF3 complex was associated with inhibited host protein translation whereas ORF6 localization with MAVS was associated with inhibited RIG-I 2CARD-mediated IFNB1 promoter activation. Quantitative proteomics identified candidate host targets for the NSP5 protease, with specific functional cleavage sequences in host proteins CWC22 and FANCD2. This data resource identifies host factors proximal to viral proteins in living human cells and nominates pathogenic mechanisms employed by SARS-CoV-2.     

Microbiologically influenced corrosion in petroleum product pipelines--a review

Microbiologically influenced corrosion is responsible for most of the internal corrosion problems in oil transportation pipelines and storage tanks. One problematic area in treating gas lines is the occurrence of the stratification of water in the line. Under these conditions, corrosion inhibitors do not come into contact properly and oil and inhibitors undergo degradation. The role of bacteria on oil degradation, the consequences of oil degradation in fuel systems and its influence on corrosion have been explained in detail. Besides, factors influencing on degradation of oil and corrosion inhibitors have also been discussed. Mechanism of microbiologically influenced corrosion in oil pipeline has been explained. Many of the misapplication of biocides/inhibitors occur mainly because the characteristics of biocides/inhibitors are not considered before use in pipeline industry. List of biocides and monitoring programme have been collected from literature and presented.