土贝母化学成分的研究 Ⅲ.土贝母苷甲的结构

从葫芦科植物假贝母(Bolbostemma paniculatum[Maxim] Franquet)的鳞茎中分得五个苷类化合物:土贝母苷甲(1)、乙、丙、丁和戊.通过对1及其各选择性水解产物的 NMR 分析确定了它的结构,为一新的三萜皂苷.     

土贝母化学成分的研究III: 土贝母苷甲的结构

从葫芦科植物假贝母(Bolbostemma paniculatum [Maxim]Franquet)的鳞茎中分得五个苷类化合物: 土贝母苷甲、乙、丁和戊. 通过对土贝母苷甲及其各选择性水解产物的NMR分析确定了它的结构, 为一新的三萜皂苷.     

土贝母化学成分的研究 Ⅳ.土贝母苷乙、丙、丁的结构

前已报道葫芦科(Cucurbitaceae)植物假贝母(Bolbostemma paniculatum [Maxim]Franquet)鳞茎土贝母中四个三萜皂苷土贝母苷甲、乙、丙、丁的提取与分离以及土贝母苷甲的结构研究.本文继续报道其余三个皂苷的结构研究. 土贝母苷乙(1),白色粉末,C_(63)H_(98)O_(30),[α]_D—6.0(c0.32,吡啶),M_r1334(SIMS: m/(?)1335[M+H]~+).苷元为远志酸(2),所含的糖为葡萄糖、鼠李糖、阿拉伯糖和木糖,摩尔比为1:1:2:1.1的~(13)C NMR谱中显示五个糖端基碳信号(δ106.4,104.8,103.2,100.8和94.3     

黄花棘豆化学成分的研究II:两种三萜皂苷的结构

从黄花棘豆的总皂苷中分离出两个新皂苷1和2.经光谱分析及化学方法确证,1为3-O-[α-L-鼠李吡喃糖基(1→2)-β-D-葡萄吡喃糖基(1→4)-β-D-葡萄吡喃糖醛酸基]-黄豆醇B;2为3-O-[α-L-鼠李吡喃糖基(1→2)-α-L-阿拉伯吡喃糖基(1→4)-β-D-葡萄吡喃糖醛酸基]-黄豆醇B.     

海枫藤中C21甾体苷的分离和结构测定

从萝摩科植物海枫藤[Marsdenia officinalis Tsiang et P.T.Li.]的藤茎中分离得到四个C21甾体去氧糖苷(1)～(4). 通过化学降解和波谱技术, 确定它们的化学结构依次为: 12-O-桂皮酰基-20-O-乙酰基(20S)-孕甾烷-6-烯-3β,5α,8β,12β,14β, 17β,20-庚醇 3-O-甲基-6-去氧-β-D-阿洛吡喃糖基-(1→4)-β-D-夹竹桃吡喃糖基-(1→4)-β-D-磁麻吡喃糖苷(1), 12-O-桂皮酰基-20-O-乙酰基(20S)-孕甾烷-6-烯-3β,5α,8β,12β,14β,17β,20-庚醇3-O-β-D-葡萄吡喃糖基-(1→4)-3-O-甲基-6-去氧-β-D-阿洛吡喃糖基-(1→4)-β-D-磁麻吡喃糖基-(1→4)-β-D-磁麻吡喃糖苷(2), 12-O-桂皮酰基-20-O-乙酰基(20S)-孕甾烷-6- 烯-3β,5α,8β,12β,14β,17β,20-庚醇3-O-β-D-黄夹吡喃糖基-(1→4)-β-D-磁麻吡喃糖基-(1→4)-β-D-磁麻吡喃糖苷(3), 12-O-烟酰基-肉珊瑚苷元3-O-β-D-葡萄吡喃糖基-(1→4)-3-O-甲基-6-去氧-β-D-阿洛吡喃糖基-(1→4)-β-D-夹竹桃吡喃糖基- (1→4)-β-D-磁麻吡喃糖基-(1→4)-β-D-磁麻吡喃糖苷(4). 其中1和2为新化合物, 分别命名为haifengtenoside A, haifengtenoside B, 3和4分别为已知化合物mucronatoside H 和 hainaneosides A, 系首次从该植物中分离得到.     

罗汉果提取物中有效成分的结构分析

罗汉果是广西特产罗汉果属植物[Siraitia grosvenorii（Swingle）]的果实。本文对已分离纯化的罗汉果有效成分，采用UV、FTIR和ESI-MS-MS对其进行结构分析。确定组分A1是罗汉果醇-3-o-[β-D-葡萄吡喃糖基（1-6）-β-D-葡萄吡喃糖苷]-24-o-[β-D-葡萄吡喃糖基（1-2）-β-D-葡萄吡喃糖苷]，组分A2是罗汉果醇-3-o-[β-D-葡萄吡喃糖基（1-6）-β-D-葡萄吡喃糖苷]-24-o-{[β-D-葡萄吡喃糖基（1—2）]-[β-D-葡萄吡喃糖基（1—6）]-β-D-葡萄吡喃糖苷}，组分A3是罗汉果醇-3-o-[β-D-葡萄吡喃糖基（1—6）-β-D-葡萄吡喃糖基（1—2）-β-D-葡萄吡喃糖苷]-24-o-{[β-E-葡萄吡喃糖基（1—2）]-β-D-葡萄吡喃糖基（1—6）]-β-D-葡萄吡喃糖苷}。     

华萝摩的化学成分

从萝摩科植物华萝摩(Metaplexis hemsleyana Oliv.)的根中分离到四个新甾体去氧糖甙, 分别命名为hemoside A(1), hemosideB(2), hemoside C(3)和hemoside D(4)。经光谱分析及化学反应鉴定其结构依次为: 12, 20-O-二苯甲酰肉珊瑚苷元3-O-β-D-磁麻吡喃糖苷; 12, 20-O-二苯甲酰肉珊瑚苷元3-O-β-D-黄夹吡喃糖基(1→4)-β-D-夹竹桃吡喃糖基(1→4)-β-D-磁麻吡喃糖苷; 12-O-乙酰-20-O-苯甲酰肉珊瑚苷元3-O-β-D-黄夹吡喃糖基(1→4)-β-D-夹竹桃吡喃糖基(1→4)-β-D-磁麻吡喃糖苷; 吉马苷元3-O-β-D-黄夹吡喃糖基(1→4)-β-D-夹竹桃吡喃糖基(1→4)-β-D-磁麻吡喃糖苷。     

华萝摩的化学成分

从萝摩科植物华萝摩(Metaplexis hemsleyana Oliv.)的根中分离到四个新甾体去氧糖甙, 分别命名为hemoside A(1), hemosideB(2), hemoside C(3)和hemoside D(4)。经光谱分析及化学反应鉴定其结构依次为: 12, 20-O-二苯甲酰肉珊瑚苷元3-O-β-D-磁麻吡喃糖苷; 12, 20-O-二苯甲酰肉珊瑚苷元3-O-β-D-黄夹吡喃糖基(1→4)-β-D-夹竹桃吡喃糖基(1→4)-β-D-磁麻吡喃糖苷; 12-O-乙酰-20-O-苯甲酰肉珊瑚苷元3-O-β-D-黄夹吡喃糖基(1→4)-β-D-夹竹桃吡喃糖基(1→4)-β-D-磁麻吡喃糖苷; 吉马苷元3-O-β-D-黄夹吡喃糖基(1→4)-β-D-夹竹桃吡喃糖基(1→4)-β-D-磁麻吡喃糖苷。     

黄芪属植物化学研究 II: 梭果萤芪花A和B的结构鉴定

本文从梭黄芪的干燥根中分得胡罗卜芪, β-谷甾醇和两个新黄芪皂芪A和B, 经光谱和化学方法确证, 芪A为3-O-[α-L-鼠李吡喃糖基(1→2)-β-D-木吡喃糖基]-25-O-β-D-葡萄吡喃糖基环黄芪醇花B为3-O-[α-L-鼠李吡喃糖基(1→2)-(3'-O-乙酰基)-β-D-木吡喃糖基]-25-O-β-D-葡萄吡喃糖基环黄芪醇。     

黑鳗藤中C_(21)甾体苷的分离和结构测定

从萝藦科植物黑鳗藤[Stephanotis mucronta (Blanco) Merr.]的藤茎中分离 到三个C_(21)甾体去氧糖苷（1） - （3）。通过化学降解和波谱技术，确定它们 的化学结构依次为：12-O-惕各酰基-20-O-乙酰基肉珊瑚苷元3-O-β-黄夹吡喃糖基 -（1→4）-β-磁麻吡喃糖基-（1→4）-β-磁麻吡喃糖苷（1），5，6-双氢-12-O- 乙酰基-20-O-惕各酰基肉珊瑚苷元3-O-β-黄夹吡喃糖基-（1→4）-β-磁麻吡喃糖 基-（1→4）-β-磁麻吡喃糖基（2）；12-O-乙酰基-20-O（N-甲基）邻氨基苯甲酰 基肉珊瑚甘元3-O-β-黄夹吡喃糖基-（1→4）-β-磁麻吡喃糖基-（1→4）-β-磁 麻吡喃糖甘（3）。其中1和2为新化合物，分别命名为mucronatoside A， mucrontoside B。3为已知化合物stephanoside E，系首次从该植物中分离得到。     

Chemical constituents of Bolbostemma paniculatum (Maxim) Franquet: III. Structure of tubeimoside I

From the bulbs of Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), five glycosides: tubeimosides I, II, III, IV, and V were isolated. The structure of the tubeimoside I was elucidated by degradation and spectral analyses. It has inter-saccharide chain bridgied by a dicrotalic acid to form a unique macrocyclic structure.     

A New Cyclic Bisdesmoside from Tubers of Bolbostemma paniculatum

The structure of tubeimoside V (1), a new cyclic bisdesmoside, isolated from tubers of Bolbostemma paniculatum (Tu Bei Mu), was established by means of 2D NMR spectral and chemical methods. Compound 1 has inter-saccharide chain bridging by a dicrotalic acid to form aunique macrocyclic structure.     

Transformations of kurchi alkaloids—I The action of nitrous acid on holarrhimine

Holarrhimine (I), 18-hydroxy-3β,20-diamino-5-pregnene, was treated with nitrous acid under different conditions. From the reaction mixtures several crystalline products were isolated and characterized as 3β-hydroxy-18-20β-oxido-5-pregnene (II), the nitrate ester of II (III), 3β-nitro-18-20β-oxido-5-pregnene (IV), 6-methoxy-18-20β-oxido-3,5-cyclopregnane (V) and 3β,18-dihydroxy-20-amino-5-pregnene (VII). On treatment with boron trifluoride and acetic anhydride compounds II, IV, V and an unidentified compound (VI) gave the same triacetate 3β,18,20-triacetoxy-5-pregnene (VIII).     

Rapid Solvent Extraction of Tin(IV) with High Molecular Weight Amine from Hydrochloric Acid Solution

A novel method has been developed for the solvent extraction of tin(IV) from 8 M hydrochloric acid with 4% N‐n‐octylaniline. Tin(IV) from the organic phase was determined spectrophotometrically with pyrocatechol violet at 550 nm. Extraction was found to be quantitative in the range of 7–10 M hydrochloric acid. When the concentration of N‐n‐octylaniline was varied from 0.05–20% in xylene, it showed that optimum concentration was > 3%. Amongst diluents like benzene and xylene, toluene was found to be an effective diluent. Effect of shaking time, concentration of metal ion, and salting out agents was studied. Tolerance limits of various diverse ions were determined by masking interfering cations. Tin(IV) was separated from associated elements in its binary mixture with Se(IV), Sb(III), Bi(III), Pb(II), Au(III), Cu(II) and Zn(II) and from its ternary mixtures with Sb(III), Bi(III) and Cu(II), Au(III). The proposed method was applied for separation and determination of tin(IV) in tin bearing alloys and foodstuffs.     

Reductions by titanium(II) as catalyzed by titanium(IV)

The cobalt(III) complexes, [(NH3)5CoBr]2+ and [(NH3)5CoI]2+ are reduced by Ti(II) solutions containing Ti(IV), generating nearly linear (zero-order) profiles that become curved only during the last few percent of reaction. Other Co(III)-Ti(II) systems exhibit the usual exponential traces with rates proportional to [Co(III)]. Observed kinetics of the biphasic catalyzed Ti(II)-Co(III)Br and Ti(II)-Co(III)I reactions support the reaction sequence: [Ti(II)(H20)n]2+ + [Ti(IV)F5]- (k1)<==>(k -1) [Ti(II)(H2O)(n-1)]2+ + [(H2O)Ti(IV)F5]-, [Ti(II)(H2O)(n-1)]2+ + Co(III) (k2)--> Ti(III) + Co(II) with rates determined mainly by the slow Ti(IV)-Ti(II) ligand exchange (k1 = 9 x 10(-3) M(-1) s(-1) at 22 degrees C). Computer simulations of the catalyzed Ti(II)-Co(III) reaction in perchlorate-triflate media yield relative rates for reduction by the proposed active [Ti(II)(H2O)(n-1)]2+ intermediate; k(Br)/k(I) = 8.     

Sorption of palladium(II), rhodium(III), and platinum(IV) on Fe(3)O(4) nanoparticles

The adsorption of palladium(II), rhodium(III), and platinum(IV) from diluted hydrochloric acid solutions onto Fe(3)O(4) nanoparticles has been investigated. The parameters studied include the contact time and the concentrations of metals and other solutes such as H(+) and chloride. The equilibrium time was reached in less than 20 min for all metals. The maximum loading capacity of Fe(3)O(4) nanoparticles for Pd(II), Rh(III), and Pt(IV) was determined to be 0.103, 0.149, and 0.068 mmol g(-1), respectively. A sorption mechanism for Pd(II), Rh(III), and Pt(IV) has been proposed and their conditional adsorption equilibrium constants have been determined to be logK=1.72, 1.69, and 1.84, respectively. Different compositions of eluting solution were tested for the recovery of Pt(IV), Pd(II), and Rh(III) from Fe(3)O(4) nanoparticles. It was found that 0.5 mol L(-1) HNO(3) can elute all of the metal ions simultaneously, while 1 mol L(-1) NaHSO(3) was an effective eluting solution for Rh(III), and 0.5 mol L(-1) NaClO(4) for Pt(IV). In competitive adsorption, the nanoparticles showed stronger affinity for Rh(III) than for Pd(II) and Pt(IV).     

Establishment of an immunoaffinity chromatography for simultaneously selective extraction of Sudan I, II, III and IV from food samples

The establishment of an immunoaffinity chromatography (IAC) for simultaneously selective extraction of four illegal colorants Sudan dyes (Sudan I, II, II and IV) from food samples was described. The IAC column was constructed by covalently coupling monoclonal antibody (mAb) against Sudan I to CNBr-activated Sepharose 4B and packed into a common solid phase extraction (SPE) cartridge. It was observed that IAC column was able to separately capture Sudan I, II, III and IV with maximum capacity of 295, 156, 184 and 173ng, respectively. The extraction conditions including loading, washing and eluting solutions were carefully optimized. Under optimal conditions, the extraction recoveries of the IAC column for Sudan I-IV at two different spiked concentrations were within 95.3-106.9%. After 50 times repeated usage, 64% of the maximum capacity was still remained. Six food samples randomly collected from local supermarket without spiking Sudan dyes were extracted with IAC column and detected by high performance liquid chromatography (HPLC). It was found that there was no detectable Sudan II, III and IV in all six food samples, but Sudan I with the content of 2.7-134.5ngg(-1) was detected in three food samples. To further verify the extraction efficiency, other three negative samples were spiked with Sudan I-IV at the concentrations of 20ngg(-1) and 50ngg(-1), which were then extracted with IAC column. The extraction recoveries and relative standard deviation (RSD) were 68.6-96.0% and 4.8-15.2%, respectively, demonstrating the feasibility of the prepared IAC column for Sudan dyes extraction.     

Chemistry of the podocarpaceae—IV Constituents of the heartwood of Podocarpus dacrydioides A. Rich

The extractives of the heartwood of Podocarpus dacrydioides A. Rich. contain the known diterpenoid constituents, podocarpic acid (I, R = H), methyl podocarpate (I, R = CH₃), ferruginol (II), Δ⁹-dehydro-ferruginol (III), sugiol (9-ketoferruginol, IV), xanthoperol (V) (in trace amount) and a new resin acid, C₂₀H₂₈O₅, for which the name pododacric acid is proposed. A saturated hydrocarbon also isolated is probably n-heptacosane.