[Chemical components of essential oils from Meconopsis oliverana and their antioxidant activity].

Objective: To study the chemical components of essential oils from Meconopsis oliverana and their antioxidant activity.

Method: The essential oil was extracted by steam distillation, and GC-MS analysis was used to identify its constituents. The OH free radical scavenging activity of the essential oils was evaluated with an enzyme mark instrument by assay of the ability of DPPH free radical scavenging.

7-(1,3-Dioxolan-2-ylmethyl)-1,3-di-methyl-2,6-dioxo-2,3,6,7-tetra-hydro-1H-purin-9-ium tetra-chloridoferrate(III).

The asymmetric unit of the title compound, (C(11)H(15)N(4)O(4))[FeCl(4)], contains two independent protonated 7-(1,3-dioxolan-2-ylmeth-yl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione (doxofyllinium) and two tetrahedral tetra-chlorido-ferrate(III) anions. In the doxofyllinium, two disordered methyl-ene C atoms are observed in each dioxolane ring with an occupancy ratio of 0.54 (4):0.

2-Amino-3-methyl-pyridinium 2-amino-5-methyl-pyridinium sulfate monohydrate.

The asymmetric unit of the title compound, 2C(6)H(9)N(2) (+)·SO(4) (2-)·H(2)O, contains two isomeric protonated amino-methyl-pyridine cations, a sulfate anion and a solvent water mol-ecule. The cations are in the iminium tautomeric form. In the crystal structure, inter-molecular O-H⋯O, N-H⋯O and weak C-H⋯O hydrogen bonds link the components into a three-dimensional network.

Bis(2-amino-6-methyl-pyridinium) tetra-chloridocuprate(II).

The title compound, (C(6)H(9)N(2))(2)[CuCl(4)], contains a distorted tetra-hedral [CuCl(4)](2-) anion and two protonated amino-pyridinium cations. The geometries of the protonated amino-pyridinium cations reveal amine-imine tautomerism. The crystal packing is influenced by N-H⋯Cl and C-H⋯Cl hydrogen bonds and π-π stacking inter-actions [centroid-centroid distances = 3.

Cinchonidinium chloride monohydrate.

In the title salt, C(19)H(23)N(2)O(+)·Cl(-)·H(2)O, the ions and the water mol-ecule are held together by O-H⋯Cl, N-H⋯Cl, O-H⋯O, O-H⋯N and C-H⋯Cl hydrogen bonds, forming a three-dimensional framework. The vinyl group is disordered over two orientations with refined occupancies of 0.564 (16) and 0.

[Contrastive analysis of volatile oil from Serissa serissoides in different seasons].

Objective: To provide the foundation for reasonable utilization by analysing the essential oils from Serissa serissoides in different seasons.

Method: Essential oils were obtained by steam distillation. The chemical components were separated and identified by gas chromatography-mass spectrometer (GC-MS).