In the title compound, C21H24BrNO4, the dihedral angle between the heterocyclic ring and the pendant aromatic ring is 80.20 (13)°. The hexahydroquinone [i.e. the one with the C=O group] ring adopts a sofa conformation. An intra-molecular O-H⋯O hydrogen bond generates an S(6) ring motif. The ethyl group is disordered over two sets of sites with a refined site occupancy ratio of 0.633 (10):0.366 ...

Four chemical races were detected in Pulicaria dysenterica, when sampled within Europe, on the basis of the surface flavonoids present. One race uniquely contained quercetagetin 3,7-dimethyl ether and another 6-hydroxykaempferol 3,4'-dimethyl ether. A third race was based on plants having 6-hydroxykaempferol 3,7-dimethyl ether together with quercetagetin 3,7,3'-trimethyl ether. The fourth race ...

Measurement of total and trimethyl lead in mammalian tissue is described, using ion exchange/high performance liquid chromatography in tandem with flameless atomic absorption spectrometry for lead-specific detection. All lead forms in whole blood and homogenates of soft tissue--brain, kidney, and liver--were liberated from tissue binding by treatment with dilute (3N) HCl for a period of 18 hr. ...

The reaction of 2-lithio-1,3,5-trimethyl-1,3,5-triazacyclohexane with YCp(2)Cl leads to the formation of a donor-functionalised mono-anionic amide ligand, 1,3,5-trimethyl-2-(methylamidomethyl)-1,3,5-triazacyclohexane, bonded to the YCp(2) unit. The reaction involves a cleavage of the 1,3,5-triazacyclohexane ring and such a cleavage is also observed in the analogous reaction with (Me(3)C)(2)GaCl...

Homalomena cochinchinensis Engl. is a rare species which found in Southern China, Cambodia, Laos and Vietnam its chemical constituents bioactivity have not been determined yet. In this study, we identified 32 38 compounds acetone extracts of H. aerial part rhizome, respectively via gas chromatography mass spectrometry (GC/MS). The main extract the were 3-((4Z,7Z)-Heptadeca-4,7-dien-1-yl)phenol ...

A semiquantitative analytical method has been developed for the determination of the total quinonoid content (o-benzoquinones and p-benzoquinones) of soluble lignins. The method is based on detailed measurements and observations made with model oand p-quinones, which in dry organic solvents were shown to form adducts with trimethyl phosphite in quantitative yield. These adducts gave 31P NMR sig...

The title compound, [NiCl(2)(C(3)H(9)P)(3)], was obtained as a product of the reaction of [NiCl(2)(PMe(3))(2)] with an equivalent trimethyl-phosphine in diethyl ether. It easily loses trimethyl-phosphine at room temperature to give NiCl(2)(PMe(3))(2). There are two independent mol-ecules in the asymmetric unit, and their bond lengths and angles are similar. The Ni environment is trigonal bipyra...

Using the DNA duplex containing an AP site (5'-TCC AGX GCA AC-3'/3'-AGG TCN CGT TG-5', X = AP site, N = A, T, C, or G), we have found that 2-amino-4-hydroxypteridine (pterin) selectively binds to guanine (G), and that the enhanced binding affinity for G is obtained by its methylated derivative 2-amino-6,7-dimethyl-4-hydroxypteridine (diMe pteridine). Similarly, among the cytosine (C)-selective ...