Search

A new cytotoxic macrocyclic diterpenoid named Japodagrol, C20H28O4, has been isolated from the ornamental plantJatropha podagrica, family Euphorbiaceae, grown in Nigeria. The structure of the title compound, C20H28O4, was solved by X-ray analysis.Mr=332.44, monoclinic space groupC2,a=23.285(4),b=6.5105(12),c=12.505(3) Å,ß=98.504(17),V=1874.8 Å3,Z=4,Dc=1.178 Mg/m3. CuKa radiation (graphite crystal monochromator, ?=1.54184 A),µ (CuKa)=6.13 cm-1,F(000)=720,T=290 K. Final conventionalR factor=0.035,Rw=0.038 for 3349 “observed” reflections. The structure was solved with the programDirdif. The 5-membered ring is closed to a half-chair form. The compound contains inter- and intramolecular hydrogen bonds.

The X-ray crystal structure of the title compound, [Co(NCS)2(C6H6N4)2(H2O)2], has been determined. The crystals are monoclinic, space groupC2/c, with cell dimensionsa=15.6901(5),b=7.9248(10),c=16.1278(12) Å,ß=94.4(8)°Vc=1999.44 Å3,Mr=479.18,Z=4,Dx=1.5918 Mg m3,Cu Ka radiation (graphite crystal monochromator, ?=1.54051 Å), µ(CuKa)=39.08 cm-1,F(000)=980.00 andT=290 K. Final conventionalR-factor=0.051, andRw=0.053 for 1430 “observed” reflections and 141 variables. The structure was solved using the programsPatsys andDirdif. The Co atom is octahedrally coordinated (CoN2O2N2 chromophore), with only the 5-methyl-[1,2,4]-triazolo[1,5-a]pyrimidine (5mtp) ligands in thetrans positions. The triazolo pyrimidine rings are planar and coordinated through their N(3) atoms. The H2O ligands are also H-bond donors to N(4) (intramolecularly) and to the S atoms of the NSC anions (intermolecularly).

The structure of the title compound (C10H8N8Br2Zn·1/2H2O), prepared from the ligand and zinc bromide in ethanol, was solved by X-rays analysis.Mr=465.18, monoclinic, space groupP21/n,a=21.2376(11),b=7.1339(6),c=20.0469(11) Å,ß=98.583(4)°,Vc=3003.2 Å3,Z=8,Dx=2.057 Mg m-3,µ(Cu Ka)=87 cm-1,F(000)=1832,T=300 K. Final conventionalR-factor=0.034 andRw=0.036 for 4255 unique reflections withI> 3s(I) out of 5685 measurements. The structure was solved using automatic programsPatsys andDirdif. The two independent molecules are almost identical. The Zn atom is tetrahedrally coordinated by two Br atoms and two N(3) atoms of the triazolopyrimidine ligands. The planar triazolopyrimidine ligands make angles of 94.0 and 57.5° (moleculeA) with the ZnBr2 plane (98.6 and 57.0° for moleculeB). The water molecule is involved in hydrogen bonds with bromine only.