Synthesis and Crystal Structure of N-[(2S)-4-bromo-2-(L-menthyloxy)-5-oxo-2,5-dihydro-3-furyl]-L-leucine

Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in one-pot process via the tandem Michael addition-elimination reaction in the presence of potassium hydroxide.The chemical structure and absolute configuration of the title compound were confirmed via rotation,UV-Vis,FT-IR,1H NMR,13C NMR,MS and elemental analysis,especially by the X-ray single-crystal diffraction.The crystal crystallizes in an orthorhombic system,space group P212121 with a = 12.5249（16）,b = 19.005（3）,c = 19.719（3） ,V = 4693.7（10） 3,Z = 8,Dc = 1.263 g/m3,μ = 1.778 mm-1,F（000） = 1872,the final R = 0.0617 and wR = 0.1576 for 3967 observed reflections（I 2σ（I））.X-ray analysis reveals that the title compound has two independent molecules in the asymmetric part of the unit cell with the two five-membered furanones being almost planar.The essential part of the electron delocalization is concentrated in the N（1）,C（3）,C（1）,C（37） and O（7） region and N（2）,C（28）,C（27）,C（30） and O（4） region in the other molecule respectively,but does not take place at the expense of delocalization within the ester function.

A New Halogenated Biindole and A New Apo-carotenone from Green Alga Chaetomorpha basiretorsa Setchell

A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi-1H-indole and 1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′- trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.

川赤芍的化学成分分离鉴定

目的:研究川赤芍的化学成分。方法:取川赤芍(30 kg),用95%乙醇回流提取4次,提取液过滤后合并,减压浓缩得浸膏,将浸膏加水混悬后依次用石油醚、二氯甲烷、乙酸乙酯、正丁醇进行萃取,得到相应的5个部位,石油醚部分、二氯甲烷部分、乙酸乙酯部分、正丁醇部分和水部分。各部位分别采用硅胶,Sephadex LH-20,ODS柱色谱及中压制备液相,高压制备液相等方法对其进行分离纯化,得到的化合物用红外、质谱、核磁共振谱等波谱技术进行鉴定。结果:从川赤芍中分离纯化得到16个化合物,分别鉴定为(1S,5R,6R)-1,8-dihydroxypin-2-en-4-one (1),(2-hydroxyl)-phenyl-methyl-β-D-xylopyranoside(2),flufuran (3),6’-O-vanillylpaeoniflorin (4),2,5-二羟基肉桂酸甲酯(5),(1S,2S,5R,6R)-1,8-dihydroxypin-4-one (6),palbinone (7),4-O-甲基芍药苷(8),4-O-乙基芍药苷(9),苯甲酰氧化芍药苷(10),苯甲酸(11),没食子酸(12),没食子酸甲酯(13),没食子酸乙酯(14),β-谷甾醇(15),1,2,3,4,6-O-五没食子酰葡萄糖(16)。结论:其中,化合物1,2为新的天然化合物,化合物3为首次从芍药属中分离得到,化合物4~7为首次从该植物中分离得到。

怀中1号鲜地黄化学成分研究

采用Toyopreal HW-40C、Sephadex LH-20、硅胶和半制备液相等多种色谱学技术从怀中1号鲜地黄中分离得到20个化合物。根据理化性质与波谱数据鉴定其结构,分别为3-methyl-2-(hydroxymethyl)-4H-pyrone-4-one(1)、3-氨基-2-吡啶乙醇(2)、(5’S)-2-oxo-N-phenylpyrrolidine-3-carboxamide (3)、焦谷氨酸甲酯(4)、吲唑(5)、尿苷(6)、腺苷(7)、rehmanalkaloid C (8)、1-(3-乙基苯基)-1,2-乙二醇(9)、(3-乙基苯基)-1,2-乙二醇(10)、2-羟甲基苯基-1-O-β-D-葡萄糖苷(11)、玉叶金花苷酸甲酯(12)、11-methylforsythide (13)、7-去氧栀子新苷(14)、1-O-α-L-鼠李糖苷(1→6)-β-D-吡喃葡萄糖苷(15)、6-deoxy-D-mannono-1,4-lactone (16)、富马酸单甲酯(17)、daphneresinol (18)、二氢槲皮素(19)、rhamnopyranosyl vaniloyl (20)。其中化合物1为新化合物,命名为3-methyl-2-(hydroxymethyl)-4H-pyrone-4-one,化合物2和3为新天然产物,化合物4、5、9~11、13、14以及16~19是从地黄属中首次分离得到的。