260 research outputs found

    Trimethylsilylnitrate: a useful reagent for direct synthesis of 2-deoxy-O-glycosides from glycals

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    Trimethylsilylnitrate acts as a useful reagent for the addition of alcohols to glycals forming 2-deoxy-O-glycosides in good to excellent yields

    Antidiabetic, Antihyperlipidemic and Antioxidant Activities of Buchanania lanzan Spreng Methanol Leaf Extract in Streptozotocin-Induced Types I and II Diabetic Rats

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    Purpose: To evaluate the antidiabetic, antihyperlipidemic and antioxidant activities of Buchanania lanzan.Methods: Wistar rats were divided into nine groups of six animals each, and 40 mg/kg of streptozotocin or streptozotocin + nicotinamide was administered intraperitonially to induce types I and II diabetes. Those with blood glucose levels > 190 ± 8 mg/dl were administered the methanol leaf extract of Buchanania lanzan (MEBL, 100 or 200 mg/kg, p.o.) or positive control for 21 days. Blood glucose, lipid profile, antioxidant enzymes and oxidative stress markers were evaluated.Results: Following induction, blood glucose level rose to 327.7 ± 47.4 mg/dl, compared to the normal value of 910 ± 3.2 mg/dl. Administration of MEBL (100 or 200 mg/kg) significantly (p < 0.05) decreased blood glucose level, serum lipid profile, and significantly (p < 0.05) increased antioxidant activity as evidenced by increase in super oxide dismutase (SOD), catalas, glutathione (GSH), and decrease in the activity of lipid peroxidation (LPO).Conclusion: MEBL exhibits antidiabetic, antihyperlipidemic and antioxidant activities in diabetic rat and needs to be further investigated for the treatment of both types I and II diabetes mellitus.Keywords: Antidiabetic, Antihyperlipidemic, Antioxidant, Buchanania lanzan

    Non-isolated Modified Quadratic Boost Converter with Midpoint Output for Solar Photovoltaic Applications

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    This paper presents a boost DC-DC converter topology with non - isolated high gain and output midpoint, to boost the voltage obtained from solar photovoltaic panels. The three-level boost converter is coupled to the output port of the single-switch quadratic boost converter to derive the proposed converter topology. The voltage gain of the proposed converter is greater than that of the classical boost converter. The voltage stress on the switches of the proposed converter is equal to half of the converter output voltage. Static analysis, operating modes, experimental waveforms in continuous current conduction and discontinuous current conduction modes are shown. A 520 W prototype converter was implemented in the laboratory and its results are presented

    Kloniranje, ekspresija i karakterizacija paraflagelarnog gena Rod 2 bičaša Trypanosoma evansi

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    Paraflagellar rod is the major structural component of the trypanosomatid flagellum and is identified as a complex lattice of filaments which runs parallel to the axoneme throughout most of the flagellar length. The present study was carried out to investigate the existence of the paraflagellar rod (PFR 2) gene in Trypanosoma evansi infecting Indian cattle. Local isolates of T. evansi collected from naturally infected cow were multiplied in Wistar rats. Complementary DNA (cDNA) was synthesized from the RNA of host cell free T. evansi parasites by reverse transcription. The gel purified PCR product (PFR 2 gene of T. evansi) was cloned into the pTZ57R/T vector system. The nucleotide sequence of the PFR 2 gene of the T. evansi S.V.V.U. isolate (Accession No. KT277497) obtained in the present study revealed 100% homology with T. evansi China isolate and 99% homology with T. evansi Izatnagar and Bikaner isolates. The recombinant protein was sub-cloned into pET 32a and expressed in the BL21 (DE3) pLysS expression system. The PFR 2 gene of T. evansi S.V.V.U. isolate was further characterized by determination of its protein profile with SDS-PAGE and western blotting. Indirect ELISA was optimized for detection of the specific antibody titre against the recombinant protein of the PFR 2 gene of T. evansi. In the kinetoplastid species the PFR 2 gene is highly conserved. Therefore the PFR 2 gene was suggested as a vaccine candidate, as well as a diagnostic antigen.Paraflagelarni štapić glavna je strukturna komponenta tripanosomskog biča i dio je kompleksa filamenaza koji teku paralelno s aksonemom duž biča. Istraživanje je provedeno kako bi se ispitalo postojanje paraflagelarnog gena Rod 2 (PFR2) u bičaša Trypanosoma evansi koji invadira goveda u Indiji. Lokalni izolat T. evansi prikupljen od prirodno invadiranih krava umnožen je u Wistar štakora. Komplementarna DNA (cDNA) sintetizirana je iz RNA obrnutom transkripcijom iz stanica neinvadiranih nositelja T. evansi parazita. Pročišćeni PCR produkt (gen PFR2 bičaša T. evansi) kloniran je u vektorski sustav pTZ57R/T. Nukleotidna sekvencija gena PFR2 bičaša T. evansi, izolat S.V.V.U. (pristupni broj KT277497) dobivena u ovom istraživanju pokazala je 100 %-tnu sličnost s izolatom T. evansi China i 99 %-tnu s izolatom T. evansi Izatnagar i Bikaner. Rekombinantni protein ponovno je kloniran u sustavu pET 32a i prikazan u sustavu BL21 (DE3) pLysS. Gen PFR2 bičaša T. evansi, izolat S.V.V.U. dalje je karakteriziran određivanjem proteinskog profila metodama SDS-PAGE i Western blotting. Indirektni test ELISA optimiziran je za dokaz titra specifičnih protutijela za rekombinantni protein gena PFR2 bičaša T. evansi. U kinetoplastida gen PFR2 izrazito je očuvan. Stoga bi se gen PFR2 mogao upotrijebiti za cjepivo te kao dijagnostički antigen

    Modulation of catalytic activity in multi-domain protein tyrosine phosphatases

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    Signaling mechanisms involving protein tyrosine phosphatases govern several cellular and developmental processes. These enzymes are regulated by several mechanisms which include variation in the catalytic turnover rate based on redox stimuli, subcellular localization or protein-protein interactions. In the case of Receptor Protein Tyrosine Phosphatases (RPTPs) containing two PTP domains, phosphatase activity is localized in their membrane-proximal (D1) domains, while the membrane-distal (D2) domain is believed to play a modulatory role. Here we report our analysis of the influence of the D2 domain on the catalytic activity and substrate specificity of the D1 domain using two Drosophila melanogaster RPTPs as a model system. Biochemical studies reveal contrasting roles for the D2 domain of Drosophila Leukocyte antigen Related (DLAR) and Protein Tyrosine Phosphatase on Drosophila chromosome band 99A (PTP99A). While D2 lowers the catalytic activity of the D1 domain in DLAR, the D2 domain of PTP99A leads to an increase in the catalytic activity of its D1 domain. Substrate specificity, on the other hand, is cumulative, whereby the individual specificities of the D1 and D2 domains contribute to the substrate specificity of these two-domain enzymes. Molecular dynamics simulations on structural models of DLAR and PTP99A reveal a conformational rationale for the experimental observations. These studies reveal that concerted structural changes mediate inter-domain communication resulting in either inhibitory or activating effects of the membrane distal PTP domain on the catalytic activity of the membrane proximal PTP domain

    Design and Synthesis of Metal Complexes of (2 E

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    The photocatalytic degradation has been considered to be an efficient process for the degradation of organic pollutants, which are present in the effluents released by industries. The photocatalytic bleaching of cationic dye methylene blue was carried out spectrometrically on irradiation of UV light using Cu(II), Ni(II), and Co(II) complexes of (2E)-2-[(2E)-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide (HL). The effects of pH and metal ion were studied on the efficiency of the reaction. Cu(II) complex shows better catalytic activity and the highest percentage degradation (~88.8%) of methylene blue was observed at pH 12. A tentative mechanism has also been proposed for the photocatalytic degradation of methylene blue

    Dependence of Physical Parameters of Compound Semiconductors on Refractive Index

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    Interesting relationships have been found between refractive index, plasmon energy, electronic polarisability, bond length, microhardness, bulk modulus, force constants and lattice energy. An attempt has been made for the first time to correlate only one physical parameter with others. The calculated values are in good agreement with the experimental values as well as with the values reported in the literature. Refractive index data is the only one parameter required to estimate all the above parameters

    Method development and validation of a reversed phase HPLC method for determination of Anastrazole and Temozolomide in pharmaceutical dosage form

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    A new simple assay method has been developed and validated for the determination of Anastrazole and Temozolomide using reverse-phase high-performance liquid chromatography in their pharmaceutical dosage form. The chromatographic separation was performed on an Inertsil ODS (4.6 x 150mm, 5m) using mobile phase phosphate buffer pH 3.0 and methanol of 30:70% v/v at a flow rate of 0.8mL/min. Analytes were detected at 260nm. The method was found to be linear in the concentration range of 1-5μg/mL for both medicaments with the coefficient value (R2) of >0.999. The accuracy was measured via recovery studies and found to be acceptable and the percentage recoveries were found in the range of 98.81-100.720 and 99.290-100.700%. The proposed method was successfully validated and applied for the quantitative estimation of these drugs in both bulk and tablet dosage forms. © 2020 Author(s)

    Prospects of new chickpea varieties in Andhra Pradesh

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    Andhra Pradesh is an important chickpea growing state in southern India, with spectacular increase in chickpea area from 120,000 ha in 1997/98 to 638,000 ha in 2007/08. The chickpea revolution in Andhra Pradesh has improved the prospects of many resource-poor, small land holding and rainfed farmers of Andhra Pradesh. However, the growing season of chickpea in Andhra Pradesh is warm and short (90-110 days), and drought is the foremost factor responsible for significant yield losses. Rainfall in major chickpea-growing regions is quite uncertain and erratic, resulting in poor yields. The Regional Agricultural Research Station of Acharya N G Ranga Agricultural University, Nandyal, Andhra Pradesh, India is the lead centre responsible for location-specific research in chickpea in Andhra Pradesh. With support from ICRISAT and ICAR, the centre has initiated crop improvement programmes during 2004 and has released four promising chickpea varieties for commercial cultivation. Three desi varieties viz., Nandyal Sanaga 1(NBeG 3), Dheera (NBeG 47), and Nandyal Gram 49 (NBeG 49) released for Andhra Pradesh and one large-seeded kabuli Nandyal Gram 119 (NBeG 119) released for the southern zone comprising Andhra Pradesh, Karnataka and Tamil Nadu, are cutting across chickpea growing regions of Andhra Pradesh. Nandyal Sanaga 1, released in 2012, is a bold-seeded desi variety tolerant to drought and heat; Dheera released during 2015 is also a desi variety and the first of its kind in India, suitable for mechanical harvesting. Nandyal Gram 49 released during 2016 is a highyielding desi variety with attractive seeds; whereas Nandyal Gram 119 is early bold-seeded kabuli variety released during 2015. These varieties have clearly demonstrated their advantage (10%-15 % increase over popular varieties of the tract) in farmers’ holdings in large-scale demonstrations and are being preferred by farmers of not only Andhra Pradesh, but also Karnataka, Tamil Nadu, Odisha and Maharastra. Efforts are underway to promote large-scale adoption of these varieties to maximize long term productivity of chickpeas in rainfed vertisols

    RP-HPLC Method for the Simultaneous Analysis of Ambroxol Hydrochloride and Nitazoxanide in API and Tablet Dosage Form

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    Present work is aimed to develop a new simple, fat, rapid, accurate, efficient, and reproducible RP-HPLC method for the simultaneous analysis of Ambroxol Hydrochloride and Nitazoxanide in API& tablet dosage form. The chromatographic separation was performed using phenomenex C18 Column having dimensions of 4.6x250mm having particle size of 5 μm, with mobile phase consisting of Buffer PH-3.5 and Acetonitrile (40:60% v/v), flow rate was adjusted to 1.0ml/min and detection wavelength at 235 nm. The proposed method has been validated for linearity, range, precision, accuracy and robustness were within the acceptance limit according to the ICH Q2B guidelines. The retention times of Ambroxol Hydrochloride and Nitazoxanide were 2.985 mins and 5.581 mins respectively. The linearity was performed in the concentration in the range of 7.5 μg/ml to 45 μg/ml and 25 μg/ml to 150 μg/ml and with a correlation coefficient of 0.999 and 0.999 respectively. % RSD for system precision was found to be 0.212 and 0.160% RSD for repeatability 0.2 and 0.12, % RSD for intermediate precision was 0.06 and 0.06 respectively. The % percentage purity of Ambroxol Hydrochloride and Nitazoxanide was found to be 99.93% and 99.35% respectively. The method was found to be robust even by change in the mobile phase ±5% in less flow condition. © 2022 Author(s)
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