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1.
胀果皂甙Ⅲ和Ⅴ的结构鉴定   总被引:1,自引:0,他引:1  
从胀果甘草根茎中获得2个皂甙(1和3),依其理化性质和波谱分析,将其结构确定为:异甘草次酸-3-O-β-D-6"-正丁基-吡喃葡萄糖醛酸基-(1→2)-β-D-6'-乙基-吡喃葡萄糖醛酸甙(1)、异甘草次酸-3-O-β-D-6"-正丁基-吡喃葡萄糖醛酸基-(1→2)-β-D-6'-正丁基-吡喃葡萄糖酸甙(3),分别命名为胀果皂甙Ⅲ、胀果皂甙Ⅴ。  相似文献   

2.
于建新  伊向艺 《合成化学》2000,8(2):137-141
通过2,3,4,6-甲-O-乙酰基-β-D-吡喃型葡萄糖异硫氰酸酯和2,3,4-三-O-乙酰基-β-D-吡喃型木糖异硫氰酸酯与取代的芳基酰肼和亲核加成反应合成了10个1-芳酰基-4-(1’-N-2’,3’,4’,6’-四-O-乙酰基-β-D-吡喃型葡萄糖基)氨基硫脲和7个1-芳酰基-4-(1’-N-2’,3’,4’-三-O-乙酰基-β-D-吡喃型木糖基)氨基硫脲,所得化合物的结构经元素分析,IR,  相似文献   

3.
生漆多糖的分离与结构研究   总被引:7,自引:0,他引:7  
生漆用丙酮提取不溶解物,除去其水不溶部分、依次进行732阳离子交换树脂和SephadexG-100柱层析、得到白色粉末漆多糖.分子量12.5×10 ̄4.其组成为D-半乳糖、D-葡萄糖醛酸、L-阿拉伯糖和L-鼠李糖.摩尔比为7.7:1.8:0.4:0.1.经羧基还原、甲基化反应、高碘酸盐氧化、Smith降解和GC-MS、IR、 ̄1H-NMR、 ̄13C-NMR分析、结果表明,漆多糖为多分支结构、分子主链由β(1→3)D-半乳糖基构成.部分半乳糖基C_6位有支链,另有部分半乳糖基以(1→6)键连接,其中β(1→3)与β(1→6)甙键糖基组成比为1.83:1.分子的支链由葡萄糖醛酸基、阿拉伯糖基、鼠李糖基组成,并且葡萄糖醛酸基构成分子的末端基.  相似文献   

4.
苏小笛  朱敏 《应用化学》1997,14(3):33-36
本以β-环糊精(β-CD)和表面活性剂为增效剂,分别研究了它们对以Fe-meso-(四(4-磺基苯)卟啉)(Fe-TPPS4)为催化剂,催化过氧化氢氧化4-氨基安替比林(4-AAP)与苯酚衍生物显色反应的速度和灵敏度的影响,发现β-CD和十二烷基苯磺酸钠(SDBS)对该体系具有明显的增效作用,在3×10^-3mol/Lβ-CD存在下,测定H2O的灵敏度比献报道的提高了1.56倍,利用SDBS深  相似文献   

5.
首次报道了以D-葡萄糖为原料合成新型光学活性葡萄糖衍生类β-氨基醇化合物的新方法。目标化合物:(2S,3S)-甲基-2-脱氧-2-苯胺基-4,6-o-苄叉基-α-D-吡喃阿卓糖苷(7)经各种分析测试手段证实。  相似文献   

6.
朝藿甙E的分离和结构   总被引:7,自引:0,他引:7  
从朝鲜淫羊藿的地上部分分离到2个化合物,经化学和光谱方法鉴定它们为5,7-二羟基-4'-甲氧基-8-异戊烯基黄酮-3-O-β-D-(2-O-乙酰基)-葡萄吡喃糖基-(1-3)-α-L-(4-O-乙酰基)-鼠李吡喃糖基-7-O-β-D-葡萄吡喃糖甙(I)和β-乐淫羊藿素(Ⅱ),其中I是未见报道的化合物命名为朝藿甙-E,Ⅱ为首次从该植物中获得。  相似文献   

7.
两个非对映异构三萜皂甙的结构鉴定   总被引:7,自引:0,他引:7  
从合欢皮95%乙醇提取物中分得2个新三糖链九糖皂甙(1,2),经化学方法和光谱分析,将其结构分别鉴定为:3-O-[β-D-吡喃木糖基-(1→6)-β-D-葡萄糖基]-21-O-{(6S)-2-反式-2,6-二甲基-6-O-[4-O-((6R)-2-反式-2,6-二甲基-6-O-β-D-吡喃鸡纳糖基-2,7-辛二烯酸基)-β-D-吡喃鸡纳糖基}金合欢酸28-O-β-D-吡喃葡萄糖基-(1→3)-[a  相似文献   

8.
本文以β-环糊精(β-CD)和表面活性剂为增效试剂,分别研究了它们对以Fe-meso-(四(4-磺基苯)卟啉)(Fe-TPPS4)为催化剂,催化过氧化氢氧化4-氨基安替比林(4-AAP)与苯酚衍生物显色反应的速度和灵敏度的影响,发现β-CD和十二烷基苯磺酸钠(SDBS)对该体系具有明显的增效作用.在3×10-3mol/Lβ-CD存在下,测定H2O2的灵敏度比文献报道的提高了1.56倍.利用SDBS浓度与催化显色反应初速度的增加值之间的线性关系,建立了测定微量SDBS的方法  相似文献   

9.
键联环糊精、糖苷的卟啉及金属卟啉的合成   总被引:2,自引:0,他引:2  
全甲基化-6-羟基-β-环糊精(PMβ-CD-CHOH)在N2气流下与三氟甲基磺酸酐反应得到全甲基化-6-三氟甲基磺酸酯-β-环糊精(PM-β-CD-CH2OTf)(6)。6分别与5-(p-氨基苯基)-10,15,20-三苯基镍(钌羰基)卟啉「NiTPNH2P」(2)和「Ru(CO)TPNH2P」(3)综合得到化合物7和8.1-溴-2,3,4,6-O-乙酰基-α-D-葡萄糖(4)和1-溴-2,3,  相似文献   

10.
研究了含固氮酶钼微环境O_3MoS_3结构单元四个系列化合物[Mo(S,O-C_6H_4-1,2]~-(M)[Mo_2(CO)_3(S,O-C_6H_4-1,2)_3]~(2-)(D),[Mo_3(CO)_7(S,O-C_6H_4-1,2)_3]~(2-)(T),和[Mo_2Fe(CO)_4(S,O-C_6H_4-1,2)_3Cl_2]~(2-)(T_f)的合成化学与结构化学,并通过X-射线光电子能谱,红外光谱和电化学环伏安研究,深入探讨了它们的混合价,电子迁移和电化学行为,也讨论了有趣的O_3MoS_3结构单元。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

16.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

17.
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   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
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   

20.
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   

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