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).     

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。     

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)。     

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.     

苦绳的寡糖成分

从苦绳(Drehea sinensis Himsl.)中分离得到三个新化合物:苦绳双糖苷(2a),苦绳三糖苷(3a)和苦绳四糖苷(4) 经化学反应和光谱分析证明其结构依次为:β-D-黄夹吡喃糖基-(1→4)-β-D-磁麻吡喃糖甲苷;β-D-葡葡吡喃糖基-(1→4)-β-D-黄夹吡喃糖基-(1→4)-α-D-夹竹桃吡喃糖甲苷和-β-D葡萄吡喃基-(1→4)-β-D-葡萄吡喃糖基-(1→4)-β-D-黄夹吡喃糖基-(1→4)-α-D-夹竹桃吡喃糖甲苷。     

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.     

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-鼠李吡哺糖基(1→2)-α-L-阿拉伯吡哺糖基(1→4)-β-D-葡萄吡喃糖醛酸基]-黄豆醇B。     

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}。     

中药白头翁的皂苷 Ⅳ.主皂苷B_4和A_3结构的研究

白头翁皂苷B_4(1)经波谱及化学降解证实为双链苷,其结构为3(S),23-二羟基羽扇豆-20(29)-烯-28-酸的3-O-[α-L-吡喃鼠李糖基(1→2)-α-L-吡喃阿拉伯糖基]-28-O-[α-L-吡喃鼠李糖基(1→4)-β-D-吡喃葡萄糖基(1→6)]-β-D-吡喃葡萄糖酯苷。白头翁皂苷A_3(6)为与1具有相同3-O-糖链结构的单链苷。     

Monepaloside K,a New Triterpenoid Saponin from Morina nepalensis var.alba Hand.—Mazz.

One new triterpenoid saponin,monepaloside K(1) was isolated from the water-soluble part of the whole plant of a famous Tibetan medicinal herb,morina neplaensis var. alba Hand.-Mazz.Its structure was determined to be 3-O-α-L-arabinopyranosyl-(1→3)-β-D-xylopyranosyl siaresinolic acid on the basis of spectroscopic evidences,especially 2D NMR techniques.     

One‐step synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate and its characterization with 1D and 2D NMR techniques

A one‐step method was reported for the synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate by treating 7‐acetamido‐4‐hydroxy‐2‐naphthalenesulfonyl chloride with equal moles of N, N‐dimethylethylenediamine in acetonitrile in the presence of K₂CO₃. The chemical structure of the obtained compounds was characterized by MS, FTIR, ¹H NMR, ¹³C NMR, gCOSY, TOCSY, gHSQC, and gHMBC. The chemical shift differences of ¹H and ¹³C being δ 0.04 and 0.2, respectively, were unambiguously differentiated. Copyright © 2013 John Wiley & Sons, Ltd.     

Complete assignments of NMR data of 13 hydroxymethoxyflavones

Diosmetin, 5,7,3'-trihydroxy-4'-methoxyflavone shows chemopreventive, antimutagenic, and antiallergic effects. On the other hand, chrysoeriol, 5,7,4'-trihydroxy-3'-methoxyflavone induced nodABC-lacZ in Rhizobium meliloti. Both of them belong to hydroxymethoxy- flavones. One major difference between diosmetin and chrysoeriol is the substituted position of hydroxyl and methoxyl groups. In order to elucidate the relationships between their structures and activity, one of the first things to be done is the determination of their structures. However, most flavones occur widely in nature, and thus it is difficult to obtain in sufficient amounts from natural sources to identify their structures. Assignments of NMR data of several hydroxymethoxyflavones may help us to identify novel flavonoid compounds isolated from natural sources based on their NMR experiments. Therefore, we report here the complete assignments of 1H and 13C NMR data of 13 hydroxymethoxyflavones.     

1H, 13C, and 73Ge NMR spectral analysis of substituted aryltrimethylgermanes

NMR chemical shifts of 1H, 13C, and 73Ge are reported for a series of monosubstituted aromatic trimethylgermanes of the type XC6H4Ge(CH3)3; X = p-N(CH3)2, p-OCH3, p-OC2H5, p-C(CH3)3, p-Si(CH3)3, p-Ge(CH3)3, p-Sn(CH3)3, p-CH3, m-CH3, -H, m-OCH3, p-Cl, p-Br, m-F, m-CF3, p-CF3, o-OCH3, and o-CH3. The relatively narrow 73Ge resonances show a strong correlation with Hammett sigma constants, with a correlation coefficient of 0.976 and 0.876 for 73Ge chemical shifts in meta- and para-substituted derivatives, respectively. The 13C chemical shifts of the methyl carbons bonded to germanium also display a relationship, with correlation coefficients of 0.904, 0.993, and 0.911 for para-, meta- and all derivatives, respectively. Comparisons of the Hammett plots for the homologous series XC6H4M(CH3)3; M = C, Si, Ge, Sn, show that, in general, correlation coefficients decrease while slopes increase significantly down the group, presumably reflecting the corresponding increase in chemical shift range of the group 14 atom. The Hammett constant derived for the p-Ge(CH3)3 group of +0.13 compares with the NMR-derived constants of -0.12 for p-C(CH3)3, +0.14 for p-Si(CH3)3, and -0.14 for p-Sn(CH3)3. The indication of electron release by carbon and tin can be rationalized through traditional hyperconjugative arguments for carbon and by the low electronegativity and consequent inductive effect of tin. The small electron attraction suggested by the positive constants for silicon and germanium can be simply, and perhaps naively, attributed to pi-acceptor interactions with the benzene ring.     

An NMR crystallography investigation of furosemide

This paper presents an NMR crystallography study of three polymorphs of furosemide. Experimental magic-angle spinning (MAS) solid-state NMR spectra are reported for form I of furosemide, and these are assigned using density-functional theory (DFT)-based gauge-including projector augmented wave (GIPAW) calculations. Focusing on the three known polymorphs, we examine the changes to the NMR parameters due to crystal packing effects. We use a recently developed formalism to visualise which regions are responsible for the chemical shielding of particular sites and hence understand the variation in NMR parameters between the three polymorphs.     

Detailed assignments of 1H and 13C NMR spectral data of 14 cyclopentane derivatives

Detailed assignments of ¹H and ¹³C NMR spectral data for 14 cyclopentane derivatives are reported. The assignments are based on 1D ¹H and ¹³C NMR and on 2D shift‐correlated [¹H, ¹³C‐HMQC], J‐resolved and NOEDIF experiments. Copyright © 2003 John Wiley & Sons, Ltd.     

1H and 13C-NMR data of hydroxyflavone derivatives

Many hydroxyflavone derivatives have been found in nature and shown to have many biological functions. Because their function is changed by the position and number of hydroxyl group, their structural identification is a fundamental and necessary step for understanding their functions. In the present study, the complete 1H and 13C NMR spectral assignments were presented for 6 hydroxyflavones, and NMR data of additional 14 hydroxyflavone derivatives were compared with those of the 6 hydroxyflavones. In addition, the partially incorrect NMR data of two of the dihydroxyflavones whose NMR data were previously reported were corrected.     

Complete assignments of 1H and 13C NMR data for ten phenylpiperazine derivatives

Ten phenylpiperazine derivatives were designed and synthesized. The first complete assignments of (1)H and (13)C NMR chemical shifts for these phenylpiperazine derivatives were achieved by means of 1D and 2D NMR techniques, including (1)H-(1)H COSY, HSQC and HMBC spectra.     

Combined ab initio computational and experimental multinuclear solid-state magnetic resonance study of phenylphosphonic acid

1H, 13C, 17O and 31P NMR parameters, including chemical shift tensors and quadrupolar parameters for 17O, were calculated for phenylphosphonic acid, C6H5PO(OH)2, under periodic boundary conditions. The results are in very good agreement with experimental data and permit the unambiguous assignment of all the sites present in the structure. In particular, the 17O NMR parameters of the P=O and P-OH environments were precisely determined, which should help in the characterization of the bonding mode of phosphonate molecules in hybrid solids. Moreover, the effect of intermolecular interactions on the NMR parameters were investigated by comparing the results of the calculations in the crystal and in an isolated molecule of phenylphosphonic acid.     

Derivatives of pyrazinecarboxylic acid: 1H, 13C and 15N NMR spectroscopic investigations

NMR spectroscopic studies are undertaken with derivatives of 2‐pyrazinecarboxylic acid. Complete and unambiguous assignment of chemical shifts (¹H, ¹³C, ¹⁵N) and coupling constants (¹H,¹H; ¹³C,¹H; ¹⁵N,¹H) is achieved by combined application of various 1D and 2D NMR spectroscopic techniques. Unequivocal mapping of ¹³C,¹H spin coupling constants is accomplished by 2D (δ,J) long‐range INEPT spectra with selective excitation. Phenomena such as the tautomerism of 3‐hydroxy‐2‐pyrazinecarboxylic acid are discussed. Copyright © 2009 John Wiley & Sons, Ltd.