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31.
A new coumadn was obtained from the stems and roots of Wikstroemia indica (L.) C.A.Mey.Its structure was elucidated as methyl 3-(2-hydroxy-4-(7-hydroxy-6-methoxy-2-oxo-2H-chromen-3-yloxy) phenyl) propanoate by spectroscopic methods. 相似文献
32.
Michael addition of indole and pyrrole to a variety ofα,β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl_3 in aqueous media to afford the corresponding products in good to excellent yields. 相似文献
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Two novel steroid-linked nitrogen mustard conjugates 1a and 1b were synthesized by using estrogenic acid 4 coupled with aniline mustard 8 and phenol mustard 13 in an esterification or amidation procedure. Preliminary cytotoxic screening on cancer cell lines in vitro showed that, the steroid-ester linked nitrogen mustard conjugate la exhibited obvious increasing of activities. 相似文献
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Abiodun Humphrey Adebayo 《中国化学快报》2009,20(8):945-948
Two novel 4,5-secoeudesmane sesquiterpenoids,oxyphyllones A(1) and B(2) were isolated from the fruits of Alpinia oxyphylla.Their structures were established by spectroscopic methods including 1D and 2D NMR spectra.These two compounds are the first example of naturally occurring sesquiterpenoids with a 4,5-secoeudesmane skeleton in the family of Zingiberaceae and oxyphyllone A(1) is the first 4,5-secoeudesmane type of 13-norsesquiterpenoid.Compounds 1 and 2 exhibited no cytotoxicities against three cancer... 相似文献
35.
Study on the inclusion interactions of berberine hydrochloride and cucurbit[7] by spectrofluorimetry
The inclusion interaction between berberine hydrochloride(BRH) and cucurbit[7](CB[7]) has been studied by spectro-fluorimetry. The result showed that CB[7]interaction with BRH to form a stable inclusion complex with an association constant of 9.57×10~4 L/mol and the fluorescence intensity of the complex was enhanced in 17 times higher than that of the studied drug itself. Based on the significant enhancement of fluorescence intensity of B RH in inclusion complex,a spetrofluorimetric method with high sens... 相似文献
36.
Convergence of triples energy in CCSD(T) and CC3 calculations with correlation-consistent basis sets
The convergence behavior of connected triples correlation energy in CCSD(T) and CC3 calculations with (aug-)cc-pVXZ basis sets has been accurately described in terms of a power law of the type E(X)=E(infinity)+AX(-4). Calculations ranging from double-Z through septuple-Z attest the validity of this X(-4) convergence model. Extrapolations generated from (X-1,X)-Z calculations yield energies of nearly (X+1)-Z quality. Typically, the fraction of triples correlation energy recovered is 0.92+/-0.05 in (D,T) extrapolations; 0.98+/-0.01 in (T,Q) extrapolations; 1.0002+/-0.0012 in (Q,5) extrapolations; and 0.9995+/-0.0005 in (5,6) extrapolations. 相似文献
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A total synthesis of glypetelotine, the first sulphur-containing indole alkaloid from the leaf extracts of Glycosmis petelotii collected in the north of Vietnam, was described from indole through 6 steps. The structure of the glypetelotine was confirmed by IR, 1H NMR, 13C NMR and MS analysis. The spectral data of synthetic compound was identical with those of natural compound. 相似文献
39.
Yan Wang Ming Lu Xu Hui Zi Jin Jian Jun Fu Xiao Jia Hu Jiang Jiang Qin Shi Kai Yan Yun Heng Shen Wei Dong Zhang 《中国化学快报》2009,20(5):586-588
A new nor-sesquiterpene lactone ainsliatone A (1) was isolated from the aerial parts of A insliaea fulvioides.Its structure was established by the basis of spectroscopic methods and single-crystal X-ray diffraction analysis. 相似文献
40.
HELMKE U.; PR?TZEL-WOLTERS D.; SCHMID S. 《IMA Journal of Mathematical Control and Information》1991,8(4):397-408
In this paper we introduce the concept of an adaptive synchronizationcontroller. Synchronization is modelled as an adaptive trackingproblem for families of interconnected linear systems. Stabilizationand tracking results are obtained for minimum-phase systems. 相似文献