6-(4-Fluoro­pheneth­yl)-7-imino-3-phenyl-2,3,6,7-tetra­hydro-1,3-thia­zolo[4,5-d]pyrimidine-2-thione

In the title compound, C19H15FN4S2, the mean plane of the thia­zolopyrimidine makes a dihedral angle of 77.6 (1)° with the attached phenyl ring. The crystal packing is stabilized by inter­molecular C—H⋯N hydrogen bonds and weak C—H—π stacking inter­actions

A comparison of acidic and enzymatic hydrolysis of rutin

Rutin and its hydrolysis products (isoquercitrin and quercetin) are widely used as important materials in food and pharmaceutical industry. In this study, the effects of various acids and enzymes as catalysts on the hydrolysis reaction of rutin were studied. In comparison with acidic and enzymatic catalysis of rutin, the research results indicated that there was a sharp difference in the selectivity of hydrolysis product between the methods. When 2.5% H3PO4, 1% HCl and 0.5% H2SO4 were used as catalysts, transformation yields of isoquercitin hydrolyzed from rutin were 9.60, 0.69 and 1.25%, but those of quercetin were 11.13, 100 and 2.57%, respectively. When hesperidinase, snailase and cellulase-T2440 were used as catalysts, transformation yields of isoquercitin hydrolyzed from rutin were 43.21, 3.07 and 0.00%, but those of quercetin were 58.10, 96.39 and 30.89%, respectively. In conclusion, the aglycon of rutin was deglycosolated easily under mild acidic hydrolysis conditions at appropriate temperatures, but its secondary glucoside was difficult to be obtained. Contrarily, the prepared isoquercitrin by enzymatic hydrolysis of rutin was preferable to the acidic hydrolysis, especially for hesperidinase.Key words: Rutin, isoquercitrin, quercetin, hydrolysis, acid, enzym

The Origin of the Prompt Emission for Short GRB 170817A: Photosphere Emission or Synchrotron Emission?

The first gravitational-wave event from the merger of a binary neutron star system (GW170817) was detected recently. The associated short gamma-ray burst (GRB 170817A) has a low isotropic luminosity (~1047 erg s−1) and a peak energy E p ~ 145 keV during the initial main emission between −0.3 and 0.4 s. The origin of this short GRB is still under debate, but a plausible interpretation is that it is due to the off-axis emission from a structured jet. We consider two possibilities. First, since the best-fit spectral model for the main pulse of GRB 170817A is a cutoff power law with a hard low-energy photon index ($\alpha =-{0.62}_{-0.54}^{+0.49}$), we consider an off-axis photosphere model. We develop a theory of photosphere emission in a structured jet and find that such a model can reproduce a low-energy photon index that is softer than a blackbody through enhancing high-latitude emission. The model can naturally account for the observed spectrum. The best-fit Lorentz factor along the line of sight is ~20, which demands that there is a significant delay between the merger and jet launching. Alternatively, we consider that the emission is produced via synchrotron radiation in an optically thin region in an expanding jet with decreasing magnetic fields. This model does not require a delay of jet launching but demands a larger bulk Lorentz factor along the line of sight. We perform Markov Chain Monte Carlo fitting to the data within the framework of both models and obtain good fitting results in both cases