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51.
Ahmed S Adat S Murrells A Owen CP 《Biochemical and biophysical research communications》2002,294(2):380-383
The synthesis, biochemical evaluation and molecular modelling of a series of N-alkylated 4-(4(')-aminobenzyl)-2-oxazolidinones is described involving the derivatisation of the starting R- or S-enantiomer of 4-benzyl-2-oxazolidinones. The compounds were tested for human placental aromatase (AR) inhibition in vitro and were found, in general, to be more potent than the standard compound, aminoglutethimide (AG). The inhibitory activity of the compounds was rationalised through the use of the novel substrate-heme complex (SHC) approach and suggests that the S-enantiomer based compounds protrude beyond the C(13), C(17), and C(16) area of the steroid backbone, resulting in steric hindrance with the active site of AR and thus reduced inhibitory activity. The R-enantiomer based compounds do not protrude in the same area and as such are not thought to undergo any steric hindrance and in comparison to the S-enantiomer, possess greater inhibitory activity. 相似文献
52.
Investigation of yellow flower extract of Tagetes patula L. led to the identification of an aggregate of five phytoceramides. Among them, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]icosanamide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]heneicosanamide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]docosanamide, and (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tricosanamide were identified as new compounds and termed as tagetceramides, whereas (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tetracosanamide was a known ceramide. A steroid (β‐sitosterol glucoside) was also isolated from the subsequent fraction. The structures of these compounds were determined on the basis of spectroscopic analyses, as well as chemical method. Several other compounds were also identified by GC/MS analysis. The fractions and some commercial products, a ceramide HFA, β‐sitosterol, and stigmasterol were evaluated against an economically important cyst nematode, Heterodera zeae. Ceramide HFA showed 100 % mortality, whereas, β‐sitosterol and stigmasterol were 40–50 % active, at 1 % concentration after 24 h of exposure time, while β‐sitosterol glucoside revealed no activity against the nematode. 相似文献
53.
R Shaheen E Faqeih HE Shamseldin RR Noche A Sunker MJ Alshammari T Al-Sheddi N Adly MS Al-Dosari SG Megason M Al-Husain F Al-Mohanna FS Alkuraya 《American journal of human genetics》2012,91(2):330-336
Primordial dwarfism (PD) is a phenotype characterized by profound growth retardation that is prenatal in onset. Significant strides have been made in the last few years toward improved understanding of the molecular underpinning of the limited growth that characterizes the embryonic and postnatal development of PD individuals. These include impaired mitotic mechanics, abnormal IGF2 expression, perturbed DNA-damage response, defective spliceosomal machinery, and abnormal replication licensing. In three families affected by a distinct form of PD, we identified a founder truncating mutation in POC1A. This gene is one of two vertebrate paralogs of POC1, which encodes one of the most abundant proteins in the Chlamydomonas centriole proteome. Cells derived from the index individual have abnormal mitotic mechanics with multipolar spindles, in addition to clearly impaired ciliogenesis. siRNA knockdown of POC1A in fibroblast cells recapitulates this ciliogenesis defect. Our findings highlight a human ciliopathy syndrome caused by deficiency of a major centriolar protein. 相似文献
54.
Cloning and expression of the Na+/H+ exchanger from Amphiuma RBCs: resemblance to mammalian NHE1 总被引:1,自引:0,他引:1
McLean Lee Anne; Zia Shaheen; Gorin Fredric A.; Cala Peter M. 《American journal of physiology. Cell physiology》1999,276(5):C1025
The cDNAencoding theNa+/H+exchanger (NHE) from Amphiumaerythrocytes was cloned, sequenced, and found to be highly homologous to the human NHE1 isoform (hNHE1), with 79% identity and 89%similarity at the amino acid level. Sequence comparisons with otherNHEs indicate that the Amphiumatridactylum NHE isoform 1 (atNHE1) islikely to be a phylogenetic progenitor of mammalian NHE1. The atNHE1protein, when stably transfected into the NHE-deficient AP-1 cell line(37), demonstrates robustNa+-dependent proton transportthat is sensitive to amiloride but not to the potent NHE1 inhibitorHOE-694. Interestingly, chimeric NHE proteins constructed by exchangingthe amino and carboxy termini between atNHE1 and hNHE1 exhibited drugsensitivities similar to atNHE1. Based on kinetic, sequence, andfunctional similarities between atNHE1 and mammalian NHE1, we proposethat the Amphiuma exchanger shouldprove to be a valuable model for studying the control of pH and volumeregulation of mammalian NHE1. However, low sensitivity of atNHE1 to theNHE inhibitor HOE-694 in both nativeAmphiuma red blood cells (RBCs) and intransfected mammalian cells distinguishes this transporter from itsmammalian homologue. 相似文献
55.
Ashraf SM Berger I Nazarov AA Hartinger CG Koroteev MP Nifant'ev EE Keppler BK 《化学与生物多样性》2008,5(8):1640-1644
The synthesis of metal complexes with bioligands is one option to introduce chirally defined ligands to catalysts. Herein, the hydration of nitriles to the corresponding carboxamides by use of ruthenium(II) complexes is described, which were obtained by attaching derivatives of the 3,5,6-bicyclophosphite-alpha-D-glucofuranoside ligand. 相似文献
56.
The effects of ionizing radiation on biological cells have been reported in several literatures. Most of them were mainly concerned with doses greater than 0.01 Gy and were also concerned with gamma rays. On the other hand, the studies on very low dose fast neutrons (VLDFN) are rare. In this study, we have investigated the effects of VLDFN on cell membrane and protein secondary structure of rat erythrocytes. Twelve female Wistar rats were irradiated with neutrons of total dose 0.009 Gy (241Am-Be, 0.2 mGy/h) and twelve others were used as control. Blood samples were taken at the 0, 4th, 8th, and 12th days postirradiation. Fourier transform infrared (FTIR) spectra of rat erythrocytes were recorded. Second derivative and curve fitting were used to analysis FTIR spectra. Hierarchical cluster analysis (HCA) was used to classify group spectra. The second derivative and curve fitting of FTIR spectra revealed that the most significant alterations in the cell membrane and protein secondary structure upon neutron irradiation were detected after 4 days postirradiation. The increase in membrane polarity, phospholipids chain length, packing, and unsaturation were noticed from the corresponding measured FTIR area ratios. This may be due to the membrane lipid peroxidation. The observed band shift in the CH2 stretching bands toward the lower frequencies may be associated with the decrease in membrane fluidity. The curve fitting of the amide I revealed an increase in the percentage area of α-helix opposing a decrease in the β-structure protein secondary structure, which may be attributed to protein denaturation. The results provide detailed insights into the VLDFN effects on erythrocytes. VLDFN can cause an oxidative stress to the irradiated erythrocytes, which appears clearly after 4 days postirradiation. 相似文献
57.
58.
Perveen Sumera Khan Tehmina Ahsan Shaheen Humaira Naz Rabia Hyder Muhammad Zeeshan Ijaz Bushra Naqvi S. M. Saqlan Yasmin Tayyaba 《In vitro cellular & developmental biology. Plant》2021,57(6):907-922
In Vitro Cellular & Developmental Biology - Plant - The OsRGLP1 gene was overexpressed under the control of CaMV 35S promoter in tomato (Solanum lycopersicum L.) plants using... 相似文献
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