New crystal forms and amorphous phase of sophoricoside: X-ray structures and characterization.

Sophoricoside, which is an isoflavone glycoside found in many plant species, has recently attracted attention because of its anti-fertility activity. One solvent-free form, two solvatomorphs and an amorphous phase of sophoricoside are reported for the first time. X-ray diffractometry, differential scanning calorimetry, thermal gravimetric analysis and Fourier-transform infrared spectroscopy were used to characterize the different forms. The results show that factors such as crystal symmetry, intermolecular arrangement, conformational flexibility, hydrogen-bonding interactions and solvent incorporation lead to different solid-state forms. An investigation of the transformations of the four forms showed that they can interconvert with each other under certain conditions. Amorphous phase and solvatomorphism were unstable but can improve the solubility of sophoricoside in water.

[A study of chronic hepatitis B infection superinfected with hepatitis E infection].

OBJECTIVES: To compare the influence of hepatitis E virus (HEV) infection on the replication of hepatitis B virus (HBV) by observing clinical features, the relationship between the number of HBV DNA copies in serum, the degree of hepatic function impairments and prognosis of chronic hepatitis B patients with hepatitis E superinfection. METHODS: One hundred and fifteen chronic hepatitis B (CHB) patients and 115 CHB patients with hepatitis E (HE) superinfection were studied and compared. 74 liver tissue biopsy samples of the CHB and 51 of the CHB-HE sufferers were obtained. HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc, anti-HBc-IgG, anti-HBc-IgM, HBV DNA and anti-HEVIgM were detected respectively by enzyme linked immunosorbent assay and polymerase chain reaction. RESULTS: The number of HBV DNA copies in sera in the CHB-HE group and the severity of the clinical features were significantly higher than those in the CHB group. The former group had a poorer prognosis with a 49.6% occurrence rate of severe hepatitis and a 25.2% death rate while in the latter group the corresponding rates were just 4.4% and 1.7%. CONCLUSION: Re-infection with HEV, in those CHB patients, severely damaged their hepatic functions and increased their mortality; the older the patient and the higher the level of HBV DNA, the poorer the prognosis.

[Isolation and characterization of a HCH degradation Sphingomanas sp. stain BHC-A].

An aerobic bacterium was isolated successfully from a long-term contaminated upland field, which was named BHC-A. The bacterium can utilize Hexachlorocycloexane as a sole carbon source and decompose this substance rapidly and completely. According to its physiological & biochemical characters and the homology analysis of its 16S rDNA sequence, this strain was identified as Sphingomonas sp. Stain BHC-A canmineralize not only alpha, gamma and delta-HCH rapidly, but also 5 mg/L beta-HCH in 12h completely. However, Sphingomonas paucimobilis UT26, a gamma-HCH-decomposing bacterium, can only degrade 12.6% of 5 mg/L alpha-HCH, but not beta-HCH and delta-HCH, even for more than 24h in the medium. The seedling of cucumber was selected as the model plant subject to the inhibition of HCH to the growth of cucurbitaceous plants. The results shows that the degradation of HCH isomers by BHC-A in soil is even steady and excellent, that BHC-A can eliminate the contamination of the soil and the harm to the plants.

[Cloning, expression of the gene of dehydrochlorination of BHC from enrichment and its degradation experiment].

A high effective enrichment that could degrade four isomers of BHC completely was got from the soil polluted by gamma-BHC, but the pure culture was not obtained yet. The 471 bp sequence of linN was amplified from the total DNA of enrichment by polymerase chain reaction (PCR). The nucleotide sequence analysis showed that the linN gene had high homology with reported linA up to 99%. Then the amplified fragment linN was cloned in the proper orientation into the site between Nde I and Hind III of pET-29alpha via restriction endonuclease Nde I and Hind III. The recombinant was transformed into its host E. coli strain BL21 and a recombinant protein of about 17 kD was highly expressed and showed high ability of degrading gamma-BHC after induced by IPTG. The expressed protein occupied about 30% of the total bacterial protein. The cell extracts also showed some ability of degradation of gamma-BHC. It offered basic theory for the isolation of pure culture and the construction of genetic engineering microorganisms.