西沙仙掌藻Halimeda xishensis的化学成分研究(Ⅰ)

对西沙仙掌藻Halimeda xishaensis样品进行化学成分研究,从中分离得到了三个化合物,其结构通过MS、NMR及X射线单晶衍射等波谱方法进行鉴定,确定结构为:1-正二十三碳酸甘油酯(Ⅰ),豆甾-4-烯-3β,6β-二醇(Ⅱ),丁四醇(Ⅲ);对此样品的进一步研究正在进行中.     

Isolation and Crystal Structure of Stigmast-4-ene-3β,6β-diol

The title compound (C29H50O2, Mr = 430.69) was isolated from the algae Halimeda xishaensis collected from the South China Sea. Its crystal structure was determined by single-crystal X-ray diffraction for the first time. The crystal belongs to orthorhombic, space group P212121 with a = 8.1560(13), b = 10.7861 (18), c = 29.973(5) A, V = 2636.8(8)A3, Z = 4, Dc = 1.085 g/cm3, F(000)= 960, μ(Mo-Ka) = 4.533 mm-1, λ = 0.71073 A, S = 1.061, (△ρ)max= 0.382 and (△ρ)min= -0.244e/A3. The structure was refined to R = 0.0561 and wR = O. 1553 for 2711 observed reflections with I ＞ 2σ(I). X-ray diffraction analysis reveals that the title compound has two β-OH groups, and the side chain is saturated. There exist two intermolecular hydrogen bonds between three molecules.     

利用脱镁叶绿酸甲酯的化学修饰合成红紫素酰亚胺衍生物

A series of novel purpurin-18 imide derivatives exhibiting long wavelength absorption and amphiphilicity wereobtained from methyl pheophorbide-a(MPa)by modification of the peripheral functional groups.The vinyl groupat 3-position was oxidized with OsO_4 and NaIO_4 to form the formyl group and the Grignard reaction of this alde-hyde with the alkyl magnesium bromide was carried out to give the corresponding 3-(1-hydroxylalkyl)pheophor-bide-a.The E-ring of these chlorines was converted into anhydride ring to give purpurin derivatives by air oxidation.The trans-3~2-alkyl purpurin derivatives were obtained by dehydration of hydroxyl group at 3~1-position.TheN-hydroxyl purpurin imide was generated by treatment of the anhydride ring with bydroxylamine hydrochloride.The 3~1-alkylacyl-N-hydroxyl purpurin imides were obtained by oxidation of hydroxyl group at 3~1-position.Theacylation of N-hydroxyl group was completed to afford N-acyloxy purpurin imides.The photocytoxicity of severalcompounds in vitro were tested.