OBJECTIVE:To isolate and purify three principal degraded impurities of mitiglinide calcium (impurity A,B,C) and identify their structures,establish HPLC method for content determination of impurity A,B,C. METHODS:Mitiglinide calci-um was used as raw material and reacted with acid;3 impurities were then separated by HPLC and their structures were elucidated by IR,MS,1H NMR,13C NMR,LC-ESI-MS and ORD. 3 impurities of 3 batches of mitiglinide calcium were determined,and the determination was performed on Agilent Extend-C18 column with mobile phase consisted of 0.01 mol/L sodium acetate solution-ace-tonitrile-triethylamine(60:40:0.1,pH=3.0)at the flow rate of 1.0 ml/min. The detection wavelength was set at 210 nm and sam-ple size was 20 μl. The response tests of 3 impurities and mitiglinide calcium were conducted. RESULTS:After treated with acid, impurity A,B,C had been obtained,and their purity were 99.05%,98.87%,99.98%,respectively after isolation and purifica-tion;after identifying the structure, 3 impurities were S-2-bezylsuccinic acid, S-2-bezylsuccinic acid-4-methyl ester, methyl (2S)-2-benzyl-3-(cis-hexahydroisoindolin-2-ylcarbonyl) propionate;methodological study of content determination of impurities were all up to the requirement. The linear range of impurity A,B,C were 0.387 5-3.875,0.395-3.95 and 0.392 5-3.925 μg/ml(all r were 1.000 0). The response value of impurity A,B,C and mitiglinide calcium were 2.316 1,2.636 1,2.617 8 and 2.620 4,re-spectively. CONCLUSIONS:The structures of 3 principal degraded impurities of mitiglinide calcium have been identified and con-firmed;the content of them can be determined by HPLC main component self-comparison method.

Objective To identify the sequence of hepatitis B virus S gene"a"determinant in patients with positive HBsAg and anti-HBs.Methods Nested-PCR Was used to amplify the HBV S gene in 4 patients with positive HBsAg and anti-HBs,and the PCR products were sequenced directly or after cloning.The sequences of"a" determinants were then analyzed by sequence alignment.Results Direct sequencing of PCR products showed that there was one amino acid (aa)residue in"a"determinant less conserved region emerging polymorphism in all 4 patients.Clone sequencing showed that aa residue at 126 of "a"determinant in patient 1 miSht be Thr,Ile and Set,at 134 might be Phe and Set;the aa at 126 in patient 2 misht be Ala and Thr.and in patient 3 might be Ile and Asn;aa polymorphism was not found in patient 4.Conclusion The polymorphism of"a"determinant in HBV S gene might be associated with positivity of both HBsAg and anti-HBs in hepatitis B patients.

Cashmere, also known as soft gold, is produced from the secondary hair follicles (SHFs) of cashmere goats. The number of SHFs determines the yield and quality of cashmere; therefore, it is of interest to investigate the transcriptional profiles present during cashmere goat hair follicle development. However, mechanisms underlying this development process remain largely unexplored, and studies regarding hair follicle development mostly use a murine research model. In this study, to provide a comprehensive understanding of cellular heterogeneity and cell fate decisions, single-cell RNA sequencing was performed on 19,705 single cells of the dorsal skin from cashmere goat fetuses at induction (embryonic day 60; E60), organogenesis (E90), and cytodifferentiation (E120) stages. For the first time, unsupervised clustering analysis identified 16 cell clusters, and their corresponding cell types were also characterized. Based on lineage inference, a detailed molecular landscape was revealed along the dermal and epidermal cell lineage developmental pathways. Notably, our current data also confirmed the heterogeneity of dermal papillae from different hair follicle types, which was further validated by immunofluorescence analysis. The current study identifies different biomarkers during cashmere goat hair follicle development and has implications for cashmere goat breeding in the future.

Oxidative Phosphorylation ; Acetylglucosamine ; Uridine Diphosphate N-Acetylglucosamine/metabolism*