26 research outputs found

    Identification of 5,6-trans-epoxyeicosatrienoic acid in the phospholipids of red blood cells.

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    A novel eicosanoid, 5,6-trans-epoxy-8Z,11Z,14Z-eicosatrienoic acid (5,6-trans-EET), was identified in rat red blood cells. Characterization of 5,6-trans-EET in the sn-2 position of the phospholipids was accomplished by hydrolysis with phospholipase A(2) followed by gas chromatography/mass spectrometry as well as electrospray ionization-tandem mass spectrometry analyses. The electron ionization spectrum of 5,6-erythro-dihydroxyeicosatrienoic acid (5,6-erythro-DHET), converted from 5,6-trans-EET in the samples, matches that of the authentic standard. Hydrogenation of the extracted 5,6-erythro-DHET with platinum(IV) oxide/hydrogen resulted in an increase of the molecular mass by 6 daltons and the same retention time shift as an authentic standard in gas chromatography, suggesting the existence of three olefins as well as the 5,6-erythro-dihydroxyl structure in the metabolite. Match of retention times by chromatography indicated identity of the stereochemistry of the red blood cell 5,6-erythro-DHET vis à vis the synthetic standard. High pressure liquid chromatography-electrospray ionization-tandem mass spectrometry analysis of the phospholipase A(2)-hydrolyzed lipid extracts from red blood cells revealed match of the mass spectrum and retention time of the compound with the authentic 5,6-trans-EET standard, providing direct evidence of the existence of 5,6-trans-EET in red blood cells. The presence of other trans-EETs was also demonstrated. The ability of both 5,6-trans-EET and its product 5,6-erythro-DHET to relax preconstricted renal interlobar arteries was significantly greater than that of 5,6-cis-EET. In contrast, 5,6-cis-EET and 5,6-trans-EET were equipotent in their capacity to inhibit collagen-induced rat platelet aggregation, whereas 5,6-erythro-DHET was without effect. We propose that the red blood cells serve as a reservoir for epoxides which on release may act in a vasoregulatory capacity

    Breeding tomato (Solanum lycopersicum L.) for resistance to biotic and abiotic stresses

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    Tomato (Solanum lycopersicum L.) is an important vegetable crop cultivated in the tropical and sub-tropical regions of the world. Low productivity in India is due to occurrence of both biotic and abiotic stresses. Among the biotic stresses, tomato leaf curl disease, bacterial wilt, early blight and Groundnut Bud Necrosis Virus disease have become serious production constraints causing considerable yield loss in the major tomato growing areas of the country. Adoption of multiple disease resistant varieties or F1 hybrids would be the most appropriate way to address these diseases. At ICAR-IIHR, Bengaluru systematic breeding strategies were employed to pyramid genes for resistance to early blight, bacterial wilt and tomato leaf curl diseases and to develop advanced breeding lines& F1 hybrids with triple disease resistance. Stable source of resistance to early blight and bi-partite begomo-virus (Tomato Leaf Curl New Delhi Virus) has been identified in Solanum habrochaites LA-1777. Validation with molecular markers linked to tomato leaf curl virus resistance revealed that LA-1777 carryTy2 and other putative resistant genes. Several high yielding dual purpose hybrids were also developed for fresh market and processing with high level of resistance to multiple diseases. Cherry tomato lines have also been bred for high TSS, total carotenoids, total phenols, flavonoids, vitamin C, acidity and lycopene content. IIHR-249-1, IIHR-2101 (Solanum habrochaites LA-1777), IIHR- 2866 and IIHR-2864 recorded high values for quality parameters like total carotenoids, lycopene, vitamin C, total phenols, flavonoids and TSS. Drought tolerant root stock has been developed by an interspecific cross between S. habrochaites LA-1777 and S. lycopersicum (15 SB SB). Resistant sources have also been identified against Tuta absoluta, a serious insect pest reported from major tomato growing areas in the country in recent time. High temperature tolerant breeding lines are in pipe line

    Synthesis of 6,6'-methylenebisquinazolinones and 7,7′-methylenebis-1,4-benzodiazepine- 2,5-diones

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    2405-2409New C-C linked bisquinazolinones, 6,6'-methylenebis-2-aryl-3-methyl-1,2,3,4-tetrahydroquinazolin-4(3H)-one 4, 6,6'-methylenebis-2-alkyl-3-methyl-3,4-dihydroquinazoli n-4(3H)-one 6, 6,6'-methylenebis-4-oxo-2-thio-3-aryl-1 ,2,3,4-tetrahydro quinazoline 7 and C-C linked 7,7'-methylenebis[1,4]benzodiazepine-2,5-diones 8 have been synthesised starting from bisisatoic anhydride 1

    <i>N,N</i>-Linked bisazaheterocycles: PartVI — Synthesis of tetraquinazolinones

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    2410-2413The synthesis of N,N-linked tetraquniazolinones is reported for the first time

    Synthesis of a new heterocycle,1<i>H</i>-4-aryl[1,2,4] oxadiazino[5,4-<i>b</i>]quinazolinone

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    2119-2120The synthesis of a new heterocycle, 1H-4-aryl[1,2,4]oxadiazino [5,4-b]quinazolinone, is reported

    What Object Motion Reveals About Shape With Unknown BRDF and Lighting

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    We present a theory that addresses the problem of determining shape from the (small or differential) motion of an object with unknown isotropic reflectance, under arbitrary unknown distant illumination, for both orthographic and perpsective projection. Our theory imposes fundamental limits on the hardness of surface reconstruction, independent of the method involved. Under orthographic projection, we prove that three differential motions suffice to yield an invariant that relates shape to image derivatives, regardless of BRDF and illumination. Under perspective projection, we show that four differential motions suffice to yield depth and a linear constraint on the surface gradient, with unknown BRDF and lighting. Further, we delineate the topological classes up to which reconstruction may be achieved using the invariants. Finally, we derive a general stratification that relates hardness of shape recovery to scene complexity. Qualitatively, our invariants are homogeneous partial differential equations for simple lighting and inhomogeneous for complex illumination. Quantitatively, our framework shows that the minimal number of motions required to resolve shape is greater for more complex scenes. Prior works that assume brightness constancy, Lambertian BRDF or a known directional light source follow as special cases of our stratification. We illustrate with synthetic and real data how potential reconstruction methods may exploit our framework. 1

    Protein phosphatase 2A and Ca2+-activated K+ channels contribute to 11,12-epoxyeicosatrienoic acid analog mediated mesenteric arterial relaxation

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    Epoxyeicosatrienoic acids (EETs) are considered to be endothelium-derived hyperpolarizing factors, and are potent activators of the large-conductance, Ca2+-activated K+ (BKCa) channel in vascular smooth muscle. Here, we investigate the signal transduction pathway involved in the activation of BKCa channels by 11,12-EET and 11,12-EET stable analogs in rat mesenteric vascular smooth muscle cells. 11,12-EET and the 11,12-EET analogs, 11-nonyloxy-undec-8(Z)-enoic acid (11,12-ether-EET-8-ZE), 11-(9-hydroxy-nonyloxy)-undec-8(Z)-enoic acid (11,12-ether-EET-8-ZE-OH) and 11,12-trans-oxidoeicosa-8(Z)-enoic acid (11,12-tetra-EET-8-ZE), caused vasorelaxation of mesenteric resistance arteries. Mesenteric myocyte whole-cell (perforated-patch) currents were substantially (∼150%) increased by 11,12-EET and 11,12-EET analogs. Single-channel recordings were conducted to identify the target for 11,12-EET. 11,12-EET and 11,12-EET analogs also increased mesenteric myocyte BKCa channel activity in cell-attached patches. Similar results were obtained in cell-free patches. Baseline mesenteric myocyte BKCa channel activity (NPo) in cell-free patches averaged less than 0.001 at +50 mV and 11,12-EET (1 µmol/L) increased NPo to 0.03 ± 0.02 and 11,12-EET analogs (1 µmol/L) increased NPo to 0.09 ± 0.006. Inhibition of protein phosphatase 2A (PP2A) activity with okadaic acid (10 nmol/L) completely reversed 11,12-EET stimulated BKCa channel activity and greatly attenuated 11,12-ether-EET-8-ZE mesenteric resistance artery vasorelaxation. 11,12-EET and 11,12-EET analogs increased mesenteric myocyte PP2A activity by 3.5-fold. Okadaic acid and the EET inhibitor, 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE) inhibited the 11,12-EET mediated increase in PP2A activity. These findings provide initial evidence that PP2A activity contributes to 11,12-EET and 11,12-EET analog activation of mesenteric resistant artery BKCa channels and vasorelaxation

    Cytochrome P450 Eicosanoids are Activators of Peroxisome Proliferator-Activated Receptor α

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