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51.
52.
Kundu B Rastogi SK Ahmad R Srivastava AK 《Combinatorial chemistry & high throughput screening》2002,5(7):545-550
A library of 72 compounds related to N- [4-(benzyloxy) benzoyl]alanine (I) was synthesized, prepared and screened for alpha-glucosidase inhibitory activity. Four compounds showed potent inhibition, six compounds moderate inhibition, and 16 were weak inhibitors. One compound, N- [4-(benzyloxy) benzoyl] serine, was found to be a potent inhibitor of alpha-glucosidase with 100% inhibition at 1 micro M. This inhibitor was at least five times more potent than the lead compound I. 相似文献
53.
Nonmelanoma skin cancer is the most frequently diagnosed malignancy in the United States, and multiple exposures to solar ultraviolet (UV) radiation (particularly its UV-B component, 290-320 nm), is its major cause. 'Chemoprevention' by naturally occurring agents is being appreciated as a newer dimension in the management of neoplasia including skin cancer. We recently demonstrated that resveratrol (trans-3, 5, 4-trihydroxystilbene), an antioxidant found in grapes, red wines and a variety of nuts and berries, imparts protection from acute UV-B-mediated cutaneous damages in SKH-1 hairless mice. Understanding the mechanism of resveratrol-mediated protection of UV responses is important. We earlier demonstrated that resveratrol imparts chemopreventive effects against multiple UV-exposure-mediated modulations in (1) cki-cyclin-cdk network, and (2) mitogen activated protein kinase (MAPK)-pathway. This study was conducted to assess the involvement of inhibitor of apoptosis protein family Survivin during resveratrol-mediated protection from multiple exposures of UV-B (180 mJ/cm(2); on alternate days; for a total of seven exposures) radiations in the SKH-1 hairless mouse skin. Our data demonstrated that topical pre-treatment of resveratrol (10 micromol in 200 microl acetone/mouse) resulted in significant inhibition of UV-B exposure-mediated increases in (1) cellular proliferations (Ki-67 immunostaining), (2) protein levels of epidermal cyclooxygenase-2 and ornithine decarboxylase, established markers of tumor promotion, (3) protein and messenger RNA levels of Survivin, and (4) phosphorylation of survivin in the skin of SKH-1 hairless mouse. Resveratrol pretreatment also resulted in (1) reversal of UV-B-mediated decrease of Smac/DIABLO, and (2) enhancement of UV-B-mediated induction of apoptosis, in mouse skin. Taken together, our study suggested that resveratrol imparts chemopreventive effects against UV-B exposure-mediated damages in SKH-1 hairless mouse skin via inhibiting Survivin and the associated events. 相似文献
54.
Ahmad?ShaabaniEmail author Mohammad Bagher?Teimouri Hamid Reza?Bijanzadeh 《Monatshefte für Chemie / Chemical Monthly》2004,135(5):589-593
Summary. The environment-friendly one-pot three-component condensation reactions of 4-hydroxycoumarin or 4-hydroxy-6-methylpyrone, p-substituted benzaldehyde, and alkyl or aryl isocyanides to afford furocoumarines or furopyranones in water in good yields after about one hour at 75°C are reported. 相似文献
55.
Zohreh Habibi Peyman Salehi Maryam Yousefi Yahya Hejazi Ahmad Laleh Valiollah Mozaffarian Shiva Masoudi Abdolhossein Rustaiyan 《Chemistry of Natural Compounds》2006,42(6):689-692
The hydrodistilled oils from the aerial parts of Ferula latisecta and Mozaffariania insignis, which is endemic to Iran, were analyzed by GC and GC/MS. (Z)-Ocimenone (32.4%), (E)-ocimenone (20.3%), and cis-pinocarvone (11.4%) were the main components among the 22 constituents characterized in the oil of F. latisecta, representing 87.7% of the total components detected. Twenty-five compounds were identified in the oil of M. insignis, representing 99.0% of the total oil, with octyl acetate (41.1%), β-pinene (30.3%), and α-pinene (23.9%) as the main constituents. The essential oils were examined for their potential antimicrobial activities.
Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 561–563, November–December, 2006. 相似文献
56.
Single crystals of the first anhydrous thallium nickel phosphates were prepared by reaction of heterogeneous Tl/Ni/P alloys with oxygen. TlNi4(PO4)3 (pale‐yellow, orthorhombic, space group Cmc21, a = 6.441(2)Å, b = 16.410(4)Å, c = 9.624(2)Å, Z = 4) crystallizes with a structure closely related to that of NaNi4(PO4)3. Tl4Ni7(PO4)6 (yellow‐brown, monoclinic, space group Cm, a = 10.711(1)Å, b = 14.275(2)Å, c = 6.688(2)Å, β = 103.50(2)°, Z = 8) is isotypic with Na4Ni7(PO4)6, and Tl2Ni4(P2O7)(PO4)2 (brown, monoclinic, space group C2/c, a = 10.389(2)Å, b = 13.888(16)Å, c = 18.198(3)Å, β = 103.1(2)°, Z = 8) adopts the K2Ni4(P2O7)(PO4)2 structure. Tl2Ni4(P2O7)(PO4)2 could also be prepared in nearly single phase form by reaction of Tl2CO3, NiO, and (NH4)2HPO4. 相似文献
57.
The half-life of41Ca has been redetermined to be (1.01 ±0.10)×105 yr from the specific activity of a sample of enriched calcium material and its41Ca concentration. The activity was measured with a Si(Li) detector via the 3.3-keV X rays emitted in the electron capture decay of41Ca to41K. The41Ca concentration was measured by mass spectrometry. Since our result agrees well with the two most recent half-life measurements of Mabuchi et al. (1974), (1.13±0.12)×105 yr, and Klein et al. (1990), (1.03±0.07)×105 yr, we recommend the weighted mean of these three measurements, t1/2=(1.04±0.05)×105 yr, as the most accurate value of the half-life of41Ca.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday 相似文献
58.
59.
Ahmad E. Nevissi 《Journal of Radioanalytical and Nuclear Chemistry》1991,148(1):121-131
Mathematical equations governing the ratio of210Bi/210Pb and210Po/210Pb activities are used to explain the ingrowth of210Bi and210Po in environmental samples during post collection. Procedures are described for radiochemical separation of210Pb,210Bi, and210Po in a state of radioactive disequilibrium and quantification by alpha- and beta-counting. Also, the special case is considered where210Bi is in equilibrium with210Pb, but both are in disequilibrium with210Po. In this case, the activities of both210Pb and210Po are computed by measuring210Po activity twice, using alpha-counting. 相似文献
60.
Irshad Ahmad 《Zeitschrift für Physik A Hadrons and Nuclei》1979,290(1):1-5
High-precision measurements ofK Auger electron andK x-ray intensities have been made for several transuranium elements and these have been used to determineK-shell fluorescence yields (ω K ). The electron spectra were measured with a cooled Si(Li) spectrometer and the photon spectra were taken with Ge(Li) diodes. Very thin mass-separated samples of nuclides, which decay predominantly by electron capture, were used in the present experiments. From our present measurements the following values ofK- shell fluorescence yield have been obtained: Np, 97.2±0.3%; Pu, 97.2±0.4%; Cm, 97.1 ±0.6%; Bk, 97.1±0.4%; Cf, 97.3±0.4%; and Es, 97.2±0.5%. These numbers indicate that theK-fluorescence yield for elements in theZ=93 toZ=99 region remains constant within the experimental error. The weighted average of these numbers is 97.19% with external error of 0.03% and internal error of 0.17%. This value is in excellent agreement with known theoretical calculations. 相似文献