Tetrahydropyran rings are a common feature of complex polyketide natural products, but much remains to be learned about the enzymology of their formation. The enzyme SalBIII from the salinomycin biosynthetic pathway resembles other polyether epoxide hydrolases/cyclases of the MonB family, but SalBIII plays no role in the conventional cascade of ring opening/closing. Mutation in the salBIII gene...

As part of a study to characterize the detailed coordination behavior of Pu(IV), single crystal X-ray diffraction structures have been determined for Pu(IV) and Ce(IV) complexes with the naturallyoccurring ligand maltol (3-hydroxy-2-methyl-pyran-4-one) and its derivative bromomaltol (5-bromo-3-hydroxy-2-methyl-pyran-4-one). Although Ce(IV) is generally accepted as a structural analog for Pu(IV)...

In the title compound, C(27)H(15)NO(6)·0.5CHCl(3), the central pyran ring and both the benzopyran systems are planar, with the dihedral angle between the outer rings being 3.24 (6)°. The indolin-2-one system is in a perpendicular configuration with respect to the pyran ring [dihedral angle = 87.58 (2)°]. Supra-molecular layers in the ac plane are formed in the crystal structure whereby inversio...

There are two canagliflozin mol-ecules (A and B) and one water mol-ecule in the asymmetric unit of the title compound, C24H25FO5S·0.5H2O [systematic name: (2S,3R,4R,5S,6R)-2-(3-{[5-(4-fluoro-phen-yl)thio-phen-2-yl]meth-yl}-4-methylphen-yl)-6-(hy-droxy-meth-yl)-3,4,5,6-tetra-hydro-2H-pyran-3,4,5-triol hemihydrate]. The dihedral angles between the methyl-benzene and thio-phene rings are 115.7 (4)...

Pyrazoles are very important class of biologically active compounds and many of their derivatives are in clinical use. Pyrazole derivatives have been shown to exhibit antihyperglycemic [1], hypoglycemic [2] and fungicidal properties [3]. Some of them are also used as insecticides and herbicides [4,5]. Of the condensed pyrazoles, specially pyrano[2,3-c]pyrazole is a fused heterocycle comprising ...

In the title compound, C23H24F2O3, the central pyran ring has a flat-boat conformation, whereas the two fused cyclo-hexenone rings adopt envelope conformations, with the C atom bearing the dimethyl substituent being the flap atom in each case. The pyran ring mean plane and the di-fluoro-phenyl ring are almost normal to each other, making a dihedral angle of 87.55 (4)°. In the crystal, mol-ecule...

With an L1210 tumor vaccine model, three biological and two chemical agents were tested for their ability to act as adjuvants. Adjuvant was administered with irradiated L1210 cells to immunize mice against this poorly immunogenic tumor. Two chemicals, pyran copolymer and glucan, and one biological, Brucella abortus strain 456 ether extract, were shown to be strong stimulators of antitumor immun...