九子参中三个糖链上带乙酰基的新三萜皂苷-九子参苷B, C, D

从石竹科植物九子参(Silene rubicunda)根中得到四个糖链上带乙酰基的新的三萜皂苷——九子参苷A,B,C,D(rubicunosides A～D,1～4).前文已详细报道了九子参苷A的结构研究,本文报道九子参苷B,C,D的结构.通过FAB-MS和NMR,分别确定九子参苷B,C,D为糖链上带单乙酰基的三萜九糖苷、七糖苷和糖链上带双乙酰基的三萜八糖苷,分别命名为皂树酸-3-O-β-D吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→3)-β-D-吡喃木糖-(1→4)-a-L-吡喃鼠李糖-(1→4)-[β-D-吡喃葡萄糖-(1→4′)-β-D-吡喃鸡纳糖-(1→2)]-[3′-O-乙酰基]-β-D-吡喃夫糖苷(九子参苷B,2),皂树酸-3-O-β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→4)-a-L-吡喃鼠李糖-(1→4)-[4″-O-乙酰基-β-D-吡喃葡萄糖-(1→2)]-β-D-吡喃夫糖苷(九子参苷C,3),皂树酸-3-O-β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-[6′-O-正丁基]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→3)-β-D-吡喃木糖-(1→4)-a-L-吡喃鼠李糖-(1→4)-[2″-O-乙酰基-β-D-吡喃鸡纳糖-(1→2)]-[3′-O 乙酰基]-β-D-吡喃夫糖苷(九子参苷D,4).     

十二烷基β-D-葡萄吡喃糖基-(1→3)-[β-D-葡萄吡喃糖基-(1→6)]-β-D-葡萄吡喃糖基-(1→6)-β-D-葡萄吡喃糖苷的合成

本文以3-O-烯丙基-6-O-乙酰基-2,4-二-O-苯甲酰基-α-D-葡萄糖三氯乙酰亚氨酯1为原料,设计合成了尚未见报道的十二烷基β-D-葡萄吡喃糖基-(1→3)-[β-D-葡萄吡喃糖基-(1→6)]-β-D-葡萄吡喃糖基-(1→6)-β-D-葡萄吡喃糖苷6。其组成和结构已由元素分析、1H NMR、13C NMR表征。     

九子参中三个糖链上带乙酰基的新三萜皂苷-九子参苷B,C, D

从石竹科植物九子参(Silene rubicunda)根中得到四个糖链上带乙酰基的新的三萜皂苷-九子参苷A, B, C, D(rubicunosides A~D, 1~4)。前文已详细报道了九子参苷A的结构研究, 本文报道九子参苷B, C, D的结构。通过FAB-MS和NMR,分别确定九子参苷B, C, D为糖链上带单乙酰基的三萜九糖苷、七糖苷和糖链上带双乙酰基的三萜八糖苷, 分别命名为皂树酸-3-O-β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→3)-β-D-吡喃木糖-(1→4)-α-L-吡喃鼠李糖-(1→4)-[β-D-吡喃葡萄糖-(1→4')-β-D-吡喃鸡纳糖-(1→2)]-[3'-O-乙酰基]-β-D-吡喃夫糖苷(九子参苷B, 2), 皂树酸-3-O-β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃萄淘糖醛酸-28-O-β-D-吡喃木糖-(1→4)-α-L-吡喃鼠李糖-(1→4)-[4"-O-乙酰基-β-D-吡喃葡萄糖-(1→2)]-β-D-吡喃夫糖苷(九子参苷C, 3), 皂树酸-3-O-β-D－吡喃半乳糖-(1→2)-[β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-[6'-O-正丁基]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→3)-β-D-吡喃木糖-(1→4)-α-L-吡喃鼠李糖-(1→4)-[2"-O-乙酰基-β-D-吡喃鸡纳糖-(3'-O-乙酰基]-β-D-吡喃夫糖苷(九子参苷D, 4)。     

1-芳酰基-4-(1＇-N-β-D-吡喃型糖基)氨基硫脲类化合物的合成

通过2,3,4,6-四-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的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,1H NMR确证.     

3-烷基/芳基-6-(1''''-N-β-D-或-α-L-吡喃型全乙酰化糖基)- 均三唑并[3,4-b]-1,3,4-噻二唑的合成

通过2,3,4,6-四-O-乙酰基-β-D-吡喃型葡萄糖异硫氰酸酯(3)和2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖异硫氰酸酯(4)与3-烷基/芳基-4-氨基-5-巯基-1,2,4-三唑(5)在乙醇中回流,缩合得到了14个新的3-烷基/芳基-6-(1'-N-2',3',4',6'-四-O-乙酰基-β-D-吡喃型葡萄糖基或2',3',4'-三-O-乙酰基-α-L-吡喃型鼠李糖基)-均三唑并[3,4-b]-1,3,4-噻二唑类化合物(6a-6i,7a-7e),化合物结构经元素分析、IR和1H NMR确证.     

糖类研究Ⅴ.1-O-取代酰基-四-O-乙酰基-β-D-吡喃己糖的~1H NMR谱

糖酯类化合物具有抗肿瘤等的生理活性,而引起人们对它的兴趣。为了探讨这类化合物的构效关系及合成方法,我们曾报道用各种方法合成了一系列糖基酯,它们是1-O-桂皮酰基-β-D-四氧乙酰基葡萄糖(1—7),1-O-桂皮酰基-β-D-四氧乙酰基半乳糖酯(8—14),和1-O-苯甲酰基-β-D-四氧乙酰基葡萄糖     

2,6-二甲基-3,5-二氯-4-吡啶酚糖苷的合成

在相转移催化条件下, 使 a-D-乙酰基化溴代的葡萄糖、半乳糖、葡萄糖醛酸甲酯1a, 1b, 1c分别与2,6-二甲基-3,5-二氯-4-吡啶酚(俗称氯吡醇, 氯羟吡啶)作用, 合成了氯吡醇的糖苷: 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基-β-D-葡萄吡喃糖苷(2a), 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基β-D-半乳吡喃糖苷(2b), 1-O-(2'6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4-三-O-乙酰基-β-D-葡萄吡喃糖醛酸甲酯(2c)。2a, 2b, 2c分别在甲醇中氨解, 相应得到: 1-O-(2', 6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖苷(3a), 1-O(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-半乳吡喃糖苷(3b),1-O-(2', 6'-二甲基-3',5'-二氯-(4'-吡啶基)-β-D-葡萄吡喃糖醛酸酰胺(3c)。2c用CH~3ONa/CH~3OH处理, 得到1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖醛酸甲酯(3d)。     

苯丙素苷Lugrandoside的合成研究

苯丙素苷是从药用植物中提取出的具有取代苯乙基和取代肉桂酰基的一系列天然糖苷化合物的统称,其糖核一般由一到四个单糖构成.许多研究表明,这类化合物具有抗菌、抗病毒、抗肿瘤、镇痛、降压、治疗糖尿病和免疫调节等明显的生物活性[1],因此它们的合成研究已得到有机合成化学家的注意[2].二糖苯丙素苷Lugrandoside是从毛地黄属药用植物中分离出来的一种天然化合物[3],具有强的抗氧化活性[4].本文从D-葡萄糖出发,经过15步反应,得到了全保护的二糖(3,4-二-O-烯丙基)-β-苯乙基(2,3,4,6-四-O-乙酰基)-O-β-D-吡喃葡萄糖基(1→6)-4-O-(3,4-二-O-烯丙基)咖啡酰基-2,3-二-O-乙酰基-1-O-β-D-吡喃葡萄糖,脱去保护基团,最终合成出Lugrandoside的研究正在进行之中.     

相转移催化法合成1-O-酰基-四-O-乙酰基-β-D-吡喃己糖

以氯化三乙基苄基铵作为相转移催化剂, 用2, 3, 4, 6-四-O-乙酰基-β-D-溴代吡喃葡萄糖和2, 3, 4, 6-四-O-乙酰基-β-D-溴代吡喃半乳糖与羧酸反应, 合成了相应的1-O-酰基-2, 3, 4, 6-四-O-乙酰基-β-D-吡喃葡萄糖和半乳糖。通过解析这些化合物的^1H NMR和红外光谱, 确证其糖甙键构型为β。该相转移催化法具有反应条件温和, 后处理简单和立体选择性强等优点。     

水杨酸葡聚七糖苷缀合物的合成及生物活性研究

为了研究不同植物诱导剂之间的协同作用, 我们以水杨酸甲酯为原料与6-O-乙酰基-2,3,4-三-O-苯甲酰基-α-D-吡喃葡萄糖苷三氯乙酰亚胺酯偶联得化合物5, 然后脱去6-位乙酰基得受体化合物6, 化合物6与葡聚六糖三氯乙酰亚胺酯供体7偶联, 脱保护后得到葡聚七糖与水杨酸的缀合物1. 生物活性研究结果表明, 葡聚七糖还原端连有水杨酸的糖缀合物诱导植物抗病活性要比相应的七糖2高.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.