排序方式: 共有85条查询结果,搜索用时 156 毫秒
21.
Inside Back Cover: Facile and Divergent Synthesis of Lamellarins and Lactam‐Containing Derivatives with Improved Drug Likeness and Biological Activities (Chem. Asian J. 12/2015) 下载免费PDF全文
22.
Sasiwadee Boonya‐udtayan Nattawut Yotapan Christina Woo Carson J. Bruns Somsak Ruchirawat Prof. Dr. Nopporn Thasana Dr. 《化学:亚洲杂志》2010,5(9):2113-2123
The synthesis of azalamellarins, a new series of lactam analogues of biologically active lamellarins, was achieved using CuI‐mediated and microwave‐assisted C? Namide bond formation. Seventeen azalamellarins, including N‐allylazalamellarins and N‐propylazalamellarins χ‐D, L ‐N, and J‐dehydro J, were synthesized and evaluated for their cytotoxicity against the cancer cell lines HuCCA‐1, A‐549, HepG2, and MOLT‐3. The results showed that certain azalamellarins exhibited good activities in the micromolar IC50 value range (IC50=the drug concentration that causes 50 % of cell‐growth inhibition after 72 h of continuous exposure to the test molecule), comparable to their parent lamellarin analogue. 相似文献
23.
24.
Total synthesis of natural and unnatural lamellarins with saturated and unsaturated D-rings 总被引:1,自引:0,他引:1
Ploypradith P Petchmanee T Sahakitpichan P Litvinas ND Ruchirawat S 《The Journal of organic chemistry》2006,71(25):9440-9448
Twenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were synthesized according to our developed synthetic route. The key step involved the Michael addition/ring closure (Mi-RC) of the benzyldihydroisoquinoline and alpha-nitrocinnamate derivatives, which provided the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93% yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated analogues in 54-95% yield. In addition, only two steps in our developed strategy require column chromatography. 相似文献
25.
A facile and direct synthetic entry to tricyclic imidazoloisoquinolin-3-ones and benzo[a]quinolizin-4-ones is reported based on the ring annulation of 1-unsubstituted and 1-substituted dihydroisoquinolines with azlactones under neutral conditions in a one-step procedure. Bicyclic 2,3-dihydrobenzo[d]azocin-4-ones were also prepared using simple azlactone and 1-substituted dihydroisoquinolines in a one-pot reaction. [reaction: see text] 相似文献
26.
Somsak Tonmunphean Sirirat Kokpol Vudhichai Parasuk Peter Wolschann Rudolf H. Winger Klaus R. Liedl Bernd M. Rode 《Journal of computer-aided molecular design》1998,12(4):397-397
Based on the belief that structural optimization methods, producing structures more closely to the experimental ones, should give better, i.e. more relevant, steric fields and hence more predictive CoMFA models, comparative molecular field analyses of artemisinin derivatives were performed based on semiempirical AM1 and HF/3-21G optimized geometries. Using these optimized geometries, the CoMFA results derived from the HF/3-21G method are found to be usually but not drastically better than those from AM1. Additional calculations were performed to investigate the electrostatic field difference using the Gasteiger and Marsili charges, the electrostatic potential fit charges at the AM1 level, and the natural population analysis charges at the HF/3-21G level of theory. For the HF/3-21G optimized structures no difference in predictability was observed, whereas for AM1 optimized structures such differences were found. Interestingly, if ionic compounds are omitted, differences between the various HF/3-21G optimized structure models using these electrostatic fields were found. 相似文献
27.
Selective deprotection of aromatic ethers bearing two protecting groups on the same aromatic ring by solid-supported acids (Amberlyst-15 and PTS-Si) was systematically investigated. ortho-Directing protonation by the carbonyl group as well as carbocation stability and quenching are the important determining factors for the orthogonal deprotection process. Stablilized carbocations (e.g., those from the MOM and PMB groups) could be removed with high selectivity. 相似文献
28.
Tempeam A Thasana N Pavaro C Chuakul W Siripong P Ruchirawat S 《Chemical & pharmaceutical bulletin》2005,53(10):1321-1323
Rediocide G (7), a new daphnane diterpenoid, was isolated from the roots of Trigonostemon reidioides (Euphorbiaceae), together with two congeners, rediocide A and rediocide B, (+)-syringaresinol, scopoletin, tomentin and stigmasterol. The structure of the new natural product was elucidated by comparison of its NMR and mass spectral data with those of previously known rediocides and confirmed by extensive 2D NMR spectral analysis. Rediocide G (7) was found to be cytotoxic to various cancer cell lines. 相似文献
29.
30.
An aliphatic alcohol glycoside (asystoside) and an iridoid diglucoside (3'-O-beta-D-glucopyranosyl-catalpol) were isolated from the aerial part of Asystasia intrusa along with benzyl beta-D-glucopyranoside, zizybeoside I, (6S,9R)-roseoside, verbascoside, ehrenoside, 6beta-hydroxyantirrhide, angeloside, catalpol, ajugol, 6-deoxycatalpol, and scutellarioside II. The structural elucidations were based on analyses of physical and spectroscopic data. 相似文献