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1.
In this paper, we analyze the concentration behavior of a positive solution to an evolution equation with critical exponential growth on a closed Riemann surface, and particularly derive an energy identity for such a solution. This extends a result of Lamm-Robert-Struwe and complements that of Yang.  相似文献   
2.
Chromatographic separation of the crude extracts from the roots of Ventilago denticulata led to the isolation of four new anthraquinones, ventilanones L–O (1–4), together with eight known anthraquinones (5–12). Their structures were elucidated by spectroscopic methods (UV, IR, 1H NMR, 13C NMR, and 2D NMR) and mass spectrometry (MS), as well as comparison of their spectroscopic data with those reported in the literature. HDACs inhibitory activity evaluation resulted that compound 2 exhibited moderate antiproliferative activity against HeLa and A549 cell lines but nontoxic to normal cell. Molecular docking indicated the phenolic functionality of 2 plays crucial interactions with class II HDAC4 enzyme.  相似文献   
3.
4.
From the twigs of Scleropyrum wallichianum, a new unsaturated carboxylic acid, scleropyric acid (1), two new esters, beta-sitosteryl-3-O-scleropyrate (2) and stigmasteryl-3-O-scleropyrate (3), and two well-known sterols, beta-sitosterol (4) and stigmasterol (5), were isolated and characterized using spectroscopic methods. Compound 1 exhibited antimycobacterial activity with an MIC value of 25 microg/ml and showed antiplasmodial activity with an IC50 value of 7.2 microg/ml. Compounds 2 and 3 were inactive in both assays.  相似文献   
5.
Sixteen compounds were isolated from a Thai medicinal plant, Colubrina asiatica. The isolated compounds were elucidated on the basis of spectroscopic methods (IR, 1D and 2D NMR) as six triterpene acids (16), five steroids (711), one benzoic acid derivative (12), two peptides (13 and 14), one sesquiterpenoid (15) and one jujubogenin (16). Compounds 3 and 10 showed antimalarial activity against Plasmodium falciparum. Compound 5 showed antimycobacterial activity. Moreover, compounds 3, 5, 6, 10 and 14 exhibited weak cytotoxicity against cancer cell lines. Compounds 115 have been isolated for the first time from this plant.  相似文献   
6.

Abstract  

Alkaloid-like compounds containing a benzo[c]azepine core structure were successfully prepared in three steps from 5H-dibenzo[a,d]cyclohepten-5-ol via the bridging Ritter reaction. Biological studies of these compounds revealed that some of them are AChE inhibitors and antimalarial agents.  相似文献   
7.
设(M,g,e~(-f)dv_g)是n维完备光滑的度量测度空间.考虑以下非线性椭圆方程△_f~u+hu~α=0,1α(n+m)/(n+m-2)(n+m≥4)和非线性抛物方程(△_f-?/?t)u+hu~α=0,α0正解的梯度估计.对于经典的Laplace情形,Li (Li J. Gradient estimates and harnack inequalities for nonlinear parabolic and nonlinear elliptic equations on Riemannian manifolds [J]. J Funct Anal,1991, 100:233-256.)证明了正解的梯度估计和Liouville定理.在本文中,对于上述的f-Laplace方程,作者将推导出相应的结果.  相似文献   
8.
Abstract

Two new ceanothane triterpenes, 3,7-O,O-dibenzoyl ceanothic acid methylester (1) and 3-O-acetyl-7-O-benzoyl ceanothic acid methylester (2), along with nine known compounds (311), were isolated from the roots of Colubrina asiatica. The isolated compounds were identified by spectroscopic evidence. Compounds 1 and 2 showed antimalarial activity against Plasmodium falciparum with IC50 values of 4.67 and 3.07?µg/mL, respectively. Compound 2 also showed antimycobacterial activity against Mycobacterium tuberculosis (MIC 6.25?µg/mL). In addition, compounds 1, 2, 10 and 11 showed cytotoxicity against three cancer cell lines (KB, NCI-H187 and MCF-7) with IC50 values ranging from 8.32 to 46.72?µg/mL.  相似文献   
9.
Four new aristolane sesquiterpenes named nambinones A–C (13) and 1-epi-nambinone B (4), a new sesquiterpene, nambinone D (5), a known compound, aurisin A (6) as well as a new dimeric sesquiterpene, aurisin K (7), were isolated from two isolates of luminescent mushroom, Neonothopanus nambi, PW1 and PW2. These structures were established on the basis of spectroscopic evidence. The relative configuration of 6 was determined by X-ray crystallographic analysis. Compounds 6 and 7 exhibited antimalarial activity against Plasmodium falciparum and antimycobacterial activity against Mycobacterium tuberculosis. Compounds 3, 6, and 7 showed cytotoxicity against NCI-H187 cancer cell lines. In addition, 6 and 7 showed cytotoxicity against the cholangiocarcinoma cell lines.  相似文献   
10.
The authors introduce the conception of stationary map-varifold pairs and prove a compactness result.As applications,they analyse the asymptotic structure of the pseudo tangent map of stationary harmonic maps.For stationary pair,they also get a strong convergence criterion about the map part and introduce the stratification of the singular set.  相似文献   
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