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31.
RR Pandey A Srivastava R Malasoni A Naqvi A Jain JP Maikhuri S Paliwal G Gupta AK Dwivedi 《Bioorganic & medicinal chemistry letters》2012,22(17):5735-5738
A series of twenty two derivatives of 3-(1-alkyl/aminoalkyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-one and their 2-methylene derivatives were synthesized from naturally abundant cinchonine (I). Tartarate salts of these compounds were prepared and evaluated for spermicidal activity. The most active compounds (24, 27, 34, 36, and 38) showing potent spermicidal activity were further evaluated against different strains of Trichomonas vaginalis, for antimicrobial activity, in HeLa cell lines for cytotoxicity and against Lactobacillus jensenii for eco-safety. The tartarate of 3-(1-pentyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-one (27) was found to be more active than N-9 in spermicidal activity. 相似文献
32.
Farré G Sudhakar D Naqvi S Sandmann G Christou P Capell T Zhu C 《Transgenic research》2012,21(5):1093-1097
We generated transgenic rice plants overexpressing Arabidopsis thaliana ρ-hydroxyphenylpyruvate dioxygenase (HPPD), which catalyzes the first committed step in vitamin E biosynthesis. Transgenic grains accumulated marginally higher levels of total tocochromanols than controls, reflecting a small increase in absolute tocotrienol synthesis (but no change in the relative abundance of the α and γ isoforms). In contrast, there was no change in the absolute tocopherol level, but a significant shift from the γ to the α isoform. These data confirm HPPD is not rate limiting, and that increasing flux through the early pathway reveals downstream bottlenecks that act as metabolic tipping points. 相似文献
33.
Dustin E. Bosch Francis S. Willard Ravikrishna Ramanujam Adam J. Kimple Melinda D. Willard Naweed I. Naqvi David P. Siderovski 《PLoS pathogens》2012,8(2)
Heterotrimeric G-proteins are molecular switches integral to a panoply of different physiological responses that many organisms make to environmental cues. The switch from inactive to active Gαβγ heterotrimer relies on nucleotide cycling by the Gα subunit: exchange of GTP for GDP activates Gα, whereas its intrinsic enzymatic activity catalyzes GTP hydrolysis to GDP and inorganic phosphate, thereby reverting Gα to its inactive state. In several genetic studies of filamentous fungi, such as the rice blast fungus Magnaporthe oryzae, a G42R mutation in the phosphate-binding loop of Gα subunits is assumed to be GTPase-deficient and thus constitutively active. Here, we demonstrate that Gα(G42R) mutants are not GTPase deficient, but rather incapable of achieving the activated conformation. Two crystal structure models suggest that Arg-42 prevents a typical switch region conformational change upon Gαi1(G42R) binding to GDP·AlF4
− or GTP, but rotameric flexibility at this locus allows for unperturbed GTP hydrolysis. Gα(G42R) mutants do not engage the active state-selective peptide KB-1753 nor RGS domains with high affinity, but instead favor interaction with Gβγ and GoLoco motifs in any nucleotide state. The corresponding Gαq(G48R) mutant is not constitutively active in cells and responds poorly to aluminum tetrafluoride activation. Comparative analyses of M. oryzae strains harboring either G42R or GTPase-deficient Q/L mutations in the Gα subunits MagA or MagB illustrate functional differences in environmental cue processing and intracellular signaling outcomes between these two Gα mutants, thus demonstrating the in vivo functional divergence of G42R and activating G-protein mutants. 相似文献
34.
Whole apple fruit (Malus domestica Borkh.) widely differing in pigment content and composition has been examined by recording its chlorophyll fluorescence excitation and diffuse reflection spectra in the visible and near UV regions. Spectral bands sensitive to the pigment concentration have been identified, and linear models for non-destructive assessment of anthocyanins, carotenoids, and flavonols via chlorophyll fluorescence measurements are put forward. The adaptation of apple fruit to high light stress involves accumulation of these protective pigments, which absorb solar radiation in broad spectral ranges extending from UV to the green and, in anthocyanin-containing cultivars, to the red regions of the spectrum. In ripening apples the protective effect in the blue region could be attributed to extrathylakoid carotenoids. A simple model, which allows the simulation of chlorophyll fluorescence excitation spectra in the visible range and a quantitative evaluation of competitive absorption by anthocyanins, carotenoids, and flavonols, is described. Evidence is presented to support the view that anthocyanins, carotenoids, and flavonols play, in fruit with low-to-moderate pigment content, the role of internal traps (insofar as they compete with chlorophylls for the absorption of incident light in specific spectral bands), affecting thereby the shape of the chlorophyll fluorescence excitation spectrum. 相似文献
35.
Merzlyak MN Chivkunova OB Solovchenko AE Naqvi KR 《Journal of experimental botany》2008,59(14):3903-3911
The optical properties of leaves from five species, Norway maple (Acer platanoides L.), cotoneaster (Cotoneaster alaunica Golite), hazel (Corylus avellana L.), Siberian dogwood (Cornus alba L.), and Virginia creeper (Parthenocissus quinquefolia (L.) Planch.), differing in pigment composition and at different stages of ontogenesis, were studied. Anthocyanin absorption maxima in vivo, as estimated with spectrophotometry of intact anthocyanic versus acyanic leaves and microspectrophotometry of vacuoles in the leaf cross-sections, were found between 537 nm and 542 nm, showing a red shift of 5-20 nm compared with the corresponding maxima in acidic water-methanol extracts. In non-senescent leaves, strong anthocyanin absorption was found between 500 nm and 600 nm (with a 70-80 nm apparent bandwidth). By and large, absorption by anthocyanin in leaves followed a modified form of the Lambert-Beer law, showing a linear trend up to a content of nearly 50 nmol cm(-2), and permitting thereby a non-invasive determination of anthocyanin content. The apparent specific absorption coefficients of anthocyanins at 550 nm showed no substantial dependence on the species. Anthocyanin contribution to total light absorption at 550 nm was followed in maple leaves in the course of autumn senescence. Photoprotection by vacuolar anthocyanins is discussed with special regard to their distribution within a leaf; radiation screening by anthocyanins predominantly localized in the epidermal cells in A. platanoides and C. avellana leaves was also evaluated. 相似文献
36.
Azeem Z Jelani M Naz G Tariq M Wasif N Kamran-Ul-Hassan Naqvi S Ayub M Yasinzai M Amin-Ud-Din M Wali A Ali G Chishti MS Ahmad W 《Human genetics》2008,123(5):515-519
Autosomal recessive hypotrichosis (LAH3) is a rare hair disorder characterized by sparse hair on scalp and the rest of the
body of affected individuals. Recently mutations in a G protein-coupled receptor gene, P2RY5, located at LAH3 locus, have been reported in several families with autosomal recessive hypotrichosis simplex and woolly
hair. For the present study, 22 Pakistani families with autosomal recessive hypotrichosis were enrolled. Genotyping using
microsatellite markers linked to three autosomal recessive forms of hypotrichosis (LAH1, LAH2, LAH3) showed the linkage of
2 families to the LAH2 locus and 14 to the LAH3 locus. The remaining 6 families were not linked to any of the three loci.
Families linked to LAH3 locus were further subjected to screening of the P2RY5 gene with direct DNA sequencing. Three previously reported variants, c.69insCATG (p.24insHfs52), c.188A > T (p.D63V) and
c.565G > A (p.E189K) were observed in eight families. Four novel nonsynonymous sequence variants, c.8G > C (p.S3T), c.36insA
(p.D13RfsX16), c.160insA (p.N54TfsX58) and c.436G > A (p.G146R) were found to segregate within six families.
Z. Azeem, M. Jelani, G. Naz, M. Tariq, N. Wasif, S. Kamran-ul-Hassan Naqvi contributed equally to this work. 相似文献
37.
Tabassum Naqvi Trang T Duong Gihan Hashem Momotoshi Shiga Qin Zhang Sunil Kapila 《Arthritis research & therapy》2004,7(1):R1
Diseases of specific fibrocartilaginous joints are especially common in women of reproductive age, suggesting that female
hormones contribute to their etiopathogenesis. Previously, we showed that relaxin dose-dependently induces matrix metalloproteinase
(MMP) expression in isolated joint fibrocartilaginous cells. Here we determined the effects of relaxin with or without β-estradiol
on the modulation of MMPs in joint fibrocartilaginous explants, and assessed the contribution of these proteinases to the
loss of collagen and glycosaminoglycan (GAG) in this tissue. Fibrocartilaginous discs from temporomandibular joints of female
rabbits were cultured in medium alone or in medium containing relaxin (0.1 ng/ml) or β-estradiol (20 ng/ml) or relaxin plus
β-estradiol. Additional experiments were done in the presence of the MMP inhibitor GM6001 or its control analog. After 48
hours of culture, the medium was assayed for MMPs and the discs were analyzed for collagen and GAG concentrations. Relaxin
and β-estradiol plus relaxin induced the MMPs collagenase-1 and stromelysin-1 in fibrocartilaginous explants – a finding similar
to that which we observed in pubic symphysis fibrocartilage, but not in articular cartilage explants. The induction of these
proteinases by relaxin or β-estradiol plus relaxin was accompanied by a loss of GAGs and collagen in joint fibrocartilage.
None of the hormone treatments altered the synthesis of GAGs, suggesting that the loss of this matrix molecule probably resulted
from increased matrix degradation. Indeed, fibrocartilaginous explants cultured in the presence of GM6001 showed an inhibition
of relaxin-induced and β-estradiol plus relaxin-induced collagenase and stromelysin activities to control baseline levels
that were accompanied by the maintenance of collagen or GAG content at control levels. These findings show for the first time
that relaxin has degradative effects on non-reproductive synovial joint fibrocartilaginous tissue and provide evidence for
a link between relaxin, MMPs, and matrix degradation. 相似文献
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Phosphamidon intoxication (2 mg/kg body wt./day for 7 days) inhibited SOD activity, but enhanced the lipid peroxidation in various CNS regions. Administration of cithiolone (8 mg/kg body wt./day, ip for 7 days), however, elevated SOD activity and depleted lipid peroxidation. Interestingly, no significant change was observed either in SOD activity or in lipid peroxidation following simultaneous administration of phosphamidon and cithiolone. 相似文献