2-Bromo-1,6,6-trimethyl-6,7,8,9-tetra-hydro-phenanthro[1,2-b]furan-10,11-dione.

In the title compound, C19H17BrO3, the ring skeleton is located on a crystallographic mirror plane; two C atoms of the cyclo-hexene ring are disordered over the two locations to satisfy the preferred ring conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into chains along the a axis. π-π stacking inter-actions between benzo-quinone rings, with a centroid-centroid distance of 3.

A theoretical investigation of the interaction between small Pd particles and 1-butyl-3-methyl imidazolium ionic liquids with Cl-, BF4(-) and PF6(-) anions.

Density functional calculations have been used to investigate the interaction between Pd(n) clusters (n = 1-6) and 1-butyl-3-methylimidazolium (Bmim(+)) based ionic liquids (ILs) with the anions [Cl(-)], [BF(4)(-)] and [PF(6)(-)]. The interaction of small Pd(n) clusters (1 ≤ n ≤ 6) with a single cation or anion is also studied. The interaction strengths in anion-Pd(n) categories with n = 1-6 follow the trend [Cl(-)] > [BF(4)(-)] > [PF(6)(-)].

Isolation and identification of antibacterial neo-compounds from the red ants of ChangBai Mountain, Tetramorium sp.

Three novel coumarin compounds along with two known amide alkaloids were isolated from a methanol extract of the red ants of ChangBai Mountain, Tetramorium sp. Their structures were identified on the basis of IR, 2D NMR ((1)H-(1)H COSY, HSQC, HMBC and NOESY) and HRESIMS analysis. Antibacterial activity of all the compounds was evaluated using KB paper diffusion through measurement of inhibiting zone.

Secondary metabolites from the roots of Phlomis umbrosa.

The phytochemical study of the roots of Phlomis umbrosa Turcz afforded a new phenylethanoid glycoside, 3-hydroxy-4-methoxy-β-phenylethoxy-O-[2,3-diacetyl-α-l-rhamnopyranosyl-(1 → 3)]-4-O-cis-feruloyl-[β-d-apiofuranosyl-(1 → 6)]-β-d-glucopyranoside (1), and two new 28-noroleanane-derived spirocyclic triterpenoids, phlomishexaol C (2) and phlomishexaol D (3). Their structures were elucidated on the basis of 1D and 2D NMR analyses, in combination with high-resolution MS experiment.

[Studies on the chemical constituents of the flowers of Bupleurum chinese].

Objective: To study the chemical constituents of the flowers of Bupleurum chinese.

Methods: The compounds were separated by column chromatography with silica gel. Their structures were identified by spectral methods and chemical analysis.

Density functional study of hydrogen binding on gold and silver-gold clusters.

A theoretical study was carried out on the binding of hydrogen on small bimetallic Ag(m)Au(n) (m + n < or = 5) and pure Au(n) (n < or = 5) clusters with neutral, negative, and positive charge state. It is found that the composition and charge state of clusters have strong influence on the most favorable binding site. The adiabatic ionization potentials, electron affinities, and hydrogen binding energies of cluster hydrides increase with the Au content increasing for the given cluster size.

Phenylethanoid glycosides from the roots of Phlomis umbrosa.

The phytochemical study of the roots of Phlomis umbrosa Turcz. afforded three new phenylethanoid glycosides, 3'''-acetyl-O-betonyoside D (1), 2''', 3'''-di-acetyl-O- betonyoside D (2), and 3''', 4'''-di-acetyl-O-betonyoside D (3), along with five known phenylethanoid glycosides. Their structures were elucidated on the basis of spectroscopic data.

A density functional study of the interaction of NCO with small copper clusters.

Density functional calculations have been carried out for Cu(n)NCO(-), Cu(n)NCO, Cu(n)NCO(+), and Cu(n)NCO(2+) clusters. It was found that for small n, charge state has a strong influence on the NCO location site. The ground states of the neutral and anionic complex clusters have a dominantly planar structure while most of the cationic complex clusters prefer three-dimensional structures.

A novel oligosaccharide ester from Syringa pubescens.

Pubescenside A (1), a novel oligosaccharide ester, has been isolated from the flowers of Syringa pubescens, together with five known compounds D-mannitol (2), meso-inositol (3), hydrostytosol (4), glucose (5), and sucrose (6). The structure of 1 was elucidated as 1-O-[beta-D-glucopyranosyl-(1-6)-beta-D-galactopyranosyl-(1-1)-beta-D-galactopyranosyl-6]-4,4-dimethylpelargonicate by chemical and spectroscopic means. The water extract of the flowers and leaves of S.

[Inhibitory effect on male mouse procreation and chemical composition analysis of Rhynchosia volubilis ethyl acetate extract].

Objective: To study the effect of Rhynchosia volubilis Lour ethyl acetate extract (RVLEAE) on male mouse procreation and analyse their chemical composition.

Method: With the method of solvent extraction, RVLEAE was extracted and concentrated. In the experiment of mice, 80 male mice were randomly and equally divided into four groups: Normal Saline control, positive control with 0.