ABSTRACT
This study was performed to systematically investigate the polymorphism of shikimic acid. Through optimizing the recrystallization solvent, solvent volume, recrystallization temperature, time and pressure, three crystal forms were discovered and prepared. The differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffraction (PXRD) and infrared spectrometry (IR) were used to characterize these solid states. Furthermore, the influencing factor experiments were used to explore the stability of these polymorphisms and the transformation among them. Three new polymorphisms were prepared and identified. The results indicated that only PXRD could identify different polymorphisms and there was no solvent in all three crystal forms. The composition, thermodynamic property and transformation of these crystal forms were described in this work. Furthermore, an effective method for qualitative analysis of these crystal forms was established.
ABSTRACT
<p><b>AIM</b>To investigate the effects of glycyrrhiza decoction on migrating myoelectric complex (MMC) and gastrointestinal hormone in small intestine in rats.</p><p><b>METHODS</b>We observed MMC cycle,phase Ill duration,fast wave numbers of phase III of MMC in one minute, fast wave numbers of one cluster in phase III of MMC of small intestine of glycyrrhiza group and control group rats with electrophysiology method, and immunohistochemistry to examine relative content of serotonin (5-HT), substance p(SP) and vasoactive intestinal polypeptide (VIP) in small intestinal chromophil (EC) and myenteric nerve plexus in small intestine of control group and glycyrrhiza group rats.</p><p><b>RESULTS</b>Compared glycyrrhiza group with control group,we found that glycyrrhiza was able to decrease fast wave numbers in one minute and fast wave numbers in one cluster in phase III of MMC of small intestine (P < 0.05), and evidently extend small intestinal cycle of MMC (P < 0.05), it also shortened the phase III III duration (P < 0.05) or made the phase III of MMC absent. Compared glycyrrhiza group with control group it was indicated that content of 5-HT in small intestinal mucous membrane and myenteric nerve plexus was evidently decreased (P < 0.05), and content of SP in myenteric nerve plexus of small intestine of rats was evidently decreased (P < 0.05), and content of VIP in small intestine of rats was evidently increased (P < 0.05).</p><p><b>CONCLUSION</b>Glycyrrhiza is able to inhibit small intestinal motility, this inhibition is related with the amount of 5-HT, SP, VIP secreted by small intestinal mucous membrane of rats.</p>