Cardioprotective potential of Dendrobium officinale Kimura et Migo against myocardial ischemia in mice.

Dendrobium officinale Kimura et Migo has been used for thousands of years to promote body fluid production; however, little is currently known regarding its effects on the heart. The present study aimed to explore the cardioprotective potential of the water extract of Dendrobium officinale Kimura et Migo (DOE) on myocardial ischemia in mice. A mouse model of myocardial ischemia was induced following ligation of the left anterior descending coronary artery. Prior to the operation, mice were administered a vehicle or DOE for 2 weeks. Following the operation, ST elevation was measured. To estimate the extent of myocardial damage, infarct size analysis and histopathological examination were performed. The activities of cardiac marker enzymes [creatine kinase (CK)­MB and lactate dehydrogenase (LDH)] and antioxidative indicators [malondialdehyde (MDA) and superoxide dismutase (SOD)] were also analyzed to explore the underlying mechanisms. Treatment with DOE decreased infarct size and the number of apoptotic cardiomyocytes; reduced serum CK­MB, LDH and MDA activities; and increased SOD levels. According to western blotting, DOE conferred protection against myocardial ischemic injury via the regulation of Meis1 expression. These results indicated that DOE may exert potential cardioprotective effects against myocardial ischemia; these effects may be associated with its antioxidant activity, and its ability to inhibit cardiac cell apoptosis and to regulate Meis1 expression.

A novel "off-on" colorimetric and fluorescent rhodamine-based pH chemosensor for extreme acidity.

A novel "off-on" colorimetric and fluorescent rhodamine analogue was synthesized and characterized, and used to monitor extreme acidity (below pH 3.5) via the photophysical response to pH. The colorless spirocyclic structure at high pH (pH⩾7.0) opened to the colored and highly fluorescent form at very low pH (pH<3.0). This sensitive pH probe was characterized with short response time, good reversibility and no interaction with interfering metal ions, and the quantitative relationship between the fluorescence intensity and pH value was consistent with the equilibrium equation pH=pKa-log[(Imax-I)/(I-Imin)]. The fluorescent response to strong acidity was further verified by fluorescent imaging of bacteria, Escherichia coli, which contributed to the development of more useful colorimetric and fluorescent sensors based on the rhodamine platform for measuring intracellular pH in extremely acidic conditions.

Synthesis of 2H-benzo[b][1,4]oxazin-3(4H)-one derivatives as platelet aggregation inhibitors.

Novel 2H-benzo[b][1,4]oxazin-3(4H)-ones have been synthesized by condensation, reduction, O-alkylation and Smiles rearrangement using 3-bromo-4-hydroxy benzaldehyde, anilines, and chloroacetyl chloride as starting materials. All the synthesized compounds have been characterized by (1)H NMR, (13)C NMR, and HRMS, and tested for the inhibitory ability on platelet aggregation. The results have shown that the ADP (adenosine 5'-diphosphate)-induced platelet aggregation was inhibited by 7a-g with the IC(50) value at 10.14-18.83 µmol/L. Compound 7a exhibited the most potent inhibitory effect (IC(50)=10.14 µmol/L) among all the compounds, but less potent than the control drug ticlopidine (3.18 µmol/L) and aspirin (6.07 µmol/L). The preliminary structure-activity relationship (SAR) was initially investigated in the study.

8-Chloro-4-cyclo-hexyl-2H-1,4-benzoxazin-3(4H)-one.

In the crystal structure of title compound, C(14)H(16)ClNO(2), the cyclo-hexyl ring is in a chair conformation. The molecules are connected into centrosymmetric dimers via weak C-H⋯O hydrogen bonds.

4-Benzyl-7-chloro-2H-1,4-benz-oxazin-3(4H)-one.

In the title compound, C(15)H(12)ClNO(2), the two benzene rings are nearly perpendicular to each other [dihedral angle = 89.99 (13)°]. The O atom of the six-membered heterocyclic ring is disordered over two sites in a ratio of 0.46 (4):0.54 (4) and is displaced from the mean plane formed by other five atoms, resulting an envelope conformation of the six-membered hetercycle ring.

N-Benzyl-2-(2,4-dichloro-phen-oxy)acetamide.

In the title compound, C(15)H(13)Cl(2)NO(2), the dihedral angle between the aromatic rings is 27.17 (11)°. In the crystal the molecules are linked by N-H⋯O hydrogen bonds.

N-Benzyl-2-(2-chloro-4-methyl-phen-oxy)acetamide.

The structure determination of the title compound, C(16)H(16)ClNO(2), was performed as part of a project on the inter-actions between small organic mol-ecules and proteins. In the crystal structure, the dihedral angle between the two aromatic rings is 16.14 (12)°. The molecules are connected via N-H⋯O hydrogen bonding into chains, which extend in the direction of the b axis.

N-Benzyl-2-(2,6-dichloro-phen-oxy)-acetamide.

The structure determination of the title compound, C(15)H(13)Cl(2)NO(2), was undertaken as part of a project on the inter-action of small mol-ecules with proteins. In the crystal structure, the dihedral angle between the two aryl rings is 40.71 (11)°. The mol-ecules are connected via N-H⋯O hydrogen bonding into chains, which extend in the direction of the b axis.

N-Cyclo-hexyl-2-(2,3-dichloro-phen-oxy)acetamide.

In the crystal structure of title compound, C(14)H(17)Cl(2)NO(2), the cyclo-hexyl ring is in a chair conformation and the mol-ecules are connected via N-H⋯O hydrogen bonding into chains.

N-Benzyl-2-(2-chloro-5-methyl-phen-oxy)acetamide.

The asymmetric unit of the title compound, C(16)H(16)ClNO(2), contains two crystallographically independent mol-ecules, which differ mainly in the orientation of the benzyl group with respect to the rest of the mol-ecule. In the crystal packing, centrosymmetrically related mol-ecules are linked into dimers via inter-molecular C-H⋯O hydrogen-bond inter-actions.

N-Cyclo-hexyl-2-(2,3-dichloro-phenyl-sulfan-yl)acetamide.

In the crystal structure of title compound, C(14)H(17)Cl(2)NOS, the cyclo-hexyl ring has a chair conformation and connects with an equatorial N atom. Mol-ecules are connected via N-H⋯O hydrogen bonds into chains.