共查询到20条相似文献,搜索用时 46 毫秒
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软珊瑚Sarcophyton种属多含有细胞毒性的西松烷型(cembrane)的大环二萜[1~5],我们对采自中国南海西沙群岛的软珊瑚Sarcophyton crassocaule化学成分进行了生物活性跟踪研究,从对癌细胞P-388具有明显抑制活性的CHCl3提取物中分离得到了一个已知结构和两个新西松烷型(cembrane)的大环二萜.我们首次报道了其中一个结构新颖的过氧西松烷型(cembrane)的大环二萜Sarcocrassolide A(3)的分离和结构鉴定,化合物的结构经1H NMR,13C NMR,HMQC,1H-1H COSY,NOESY,FABMS和X-ray晶体衍射,确证其结构和相对构型. 相似文献
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对长叶暗罗茎的化学成分进行研究,分离得到4个新的克罗烷型二萜类化合物,通过NMR、HR-ESI-MS等多种现代波谱技术鉴定为:2-氧代-14,15,16-降三碳克罗烷-3-烯-13-酸(1)、2-氧代-14,15,16-降三碳克罗烷-3-烯-13-甲酯(2)、2-氧代-14,15,16-降三碳克罗烷-3,11E-二烯-13-酸(3)、2-氧代-16-羟基-克罗烷-3,13Z-二烯-15-酸(4).其中,化合物1~3为降三碳克罗烷型二萜,所有化合物均表现出一定的抗炎活性, IC50值范围为9.24~18.82μmol/L. 相似文献
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新的19-降海绵烷二萜的分离及结构确定 总被引:2,自引:0,他引:2
从海洋海绵Spongiazimoccaaubspeclesirregularia中分离到一种新的19-降海绵烷二萜(ZimoclactoneA,1)和胆甾-5,7-二烯-3β-醇,化合物1的化学结构和立体化学通过波谱方法和X射线单晶衍射分析确定,化合物1对P388肿瘤细胞具有中等程度的细胞毒活性. 相似文献
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《有机化学》2017,(10)
对民间丹参代用品荞麦地丹参(Salvia kiaometiensis Lévl.)乙醇提取物进行化学成分研究,通过现代多种色谱技术和波谱技术,从中分离并鉴定16个二萜类化合物,分别是6,8,11,13-abietatetraen-12-ol dimer(1),kiaometin(2),miltirone(3),tanshinone IIA(4),crypotanshione(5),tanshindiol C(6),ferruginol(7),2-isopropyl-8-methylphenanthrene-3,4-dione(8),tanshinone I(9),trijuganone B(10),dihydrotanshinone I(11),grandifolias C(12),przewalskin(13),tanshinlactone(14),6,7,8,9-tetrahydro-1,6,6-trimethylfuro[3,2-c]naphtha[2,1-e]oxepine-10,12-dione(15),almilalbanone(16).其中,化合物1为新的松香烷型二萜的二聚体,2为新的降松香烷型二萜化合物,其B环7,8位开环后又通过醚桥连接起来.所有化合物均为首次从该种植物中得到. 相似文献
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《有机化学》2016,(7)
对稀有植物四川金粟兰(Chloranthus sessilifolius)全草甲醇提取物开展进一步化学成分研究,从中分离得到2个二萜类、1个苯丙素类、1个黄酮类和1个木脂素类化合物.利用多种波谱和光谱技术(如红外、紫外、1D/2D NMR、ECD、HR-ESIMS)结合相关文献中的理化数据确定了它们的结构分别为:(3R,5S,6S,9S,10S,13S)-3,6,13-三羟基-对映松香烷-8(14)-烯-7-酮(1)、3α,15-二羟基-13α-甲氧基-对映松香烷-8(14)-烯-7-酮(2)、p-香豆酰-β-苯乙胺(3)、柚皮素三甲基醚(4)和(3R,4R,3'R,4'R)-6,6'-二甲氧基-3,4,3',4'-四氢-2H,2H'-[3,3']-双色原烯-4,4'-二醇(5).其中,化合物1为新的对映松香烷型二萜,而3~5则均为首次从金粟兰属植物中分离得到的化合物. 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献