Development of a Triphenylmethyl Alkylation Pre-Column Derivatization Method for HPLC Quantitative Analysis of Chemically Unstable Halogenated Compounds.

The primary limitations of the quantitative analysis of thermally labile halogenated compounds by traditional gas chromatography (GC) are the inadequacy of identifying the insufficiently volatile impurity (often with a high boiling point) and the difficulty in obtaining a standard substance with a reliable standardized assay. Taking the 4-(Chloromethyl)-5-methyl-1,3-dioxol-2-one (DMDO-Cl, 1) as an example, we reported a triphenylmethanamino-derivatization method to overcome the challenges of the assay determination of such species. During the quantification of 1, the presence of GC-undetectable polymeric impurity 10 poses a critical challenge in assessing the material quality. Moreover, the standard substance of 1 is not available on the market due to its inherent instability during storage and handling, further complicating the quantitative analysis. In this work, a precolumn HPLC-UV derivatization method based on triphenylmethanamino-alkylation was developed to quantitatively analyze 1. The resulting derivative 2 exhibits excellent crystallinity and superior physical and chemical stability and possesses effective chromophores for UV detection. The conversion from analyte 1 to derivative 2 demonstrates desirable reactivity and purity, facilitating quantitative analysis using the external standard method. The chemical derivatization-chromatographic detection method was optimized and validated, demonstrating its high specificity, good linearity, precision, accuracy, and stability. This method offers a valuable alternative to the general quantitative NMR (qNMR) detection technique, which exhibits reduced specificity in the presence of increased levels of impurities in compound 1.

Down-regulation of lincRNA-EPS regulates apoptosis and autophagy in BCG-infected RAW264.7 macrophages via JNK/MAPK signaling pathway.

Macrophages play a major role in the control and elimination of invading Mycobacterium tuberculosis (Mtb). Long intergenic noncoding RNA erythroid prosurvival (lincRNA-EPS) plays an important role in regulating various biologic processes in macrophages, including inflammatory responses, cell apoptosis, and autophagy. Whereas the effect of lincRNA-EPS in regulating the immune response of macrophages to Mtb is little studied. This study aimed to explore lincRNA-EPS expression in monocytes from patients with active pulmonary tuberculosis (PTB) and from healthy individuals. We also sought to investigate the effect of lincRNA-EPS on Bacillus Calmette-Guérin (BCG)-infected macrophages apoptosis and autophagy. Our study found that lincRNA-EPS expression was down-regulated in the monocytes from patients with active PTB compared with healthy individuals, accompanied by significant attenuated monocyte apoptosis and enhanced autophagy. In vitro, knockdown of lincRNA-EPS inhibited apoptosis and promoted autophagy in BCG-infected RAW264.7 macrophages. Moreover, we revealed that lincRNA-EPS regulated apoptosis and autophagy of BCG-infected RAW264.7 macrophages via JNK/MAPK signaling pathway. In conclusion, our findings demonstrated that knockdown of lincRNA-EPS inhibits apoptosis and enhances autophagy by activating the JNK/MAPK signaling pathway in BCG-infected RAW264.7 macrophages. Suggesting that lincRNA-EPS could serve as a new potential therapeutic target for PTB.

Hydrogel containing minocycline and zinc oxide-loaded serum albumin nanopartical for periodontitis application: preparation, characterization and evaluation.

Periodontal disease is a complex problem which often interrelates with several serious systemic diseases. However, the satisfactory clinical therapy has yet to be achieved. Herein, serum albumin microspheres containing minocycline and zinc oxide nanoparticals (ZnO NPs) were prepared and incorporated in a Carbopol 940® hydrogel. Compared with 2% minocycline ointment (Perio®), the hydrogel has shown obvious therapy effects and the ability of gingival tissue self-repairing. The serum albumin microspheres containing 0.06% of minocycline and 0.025% of ZnO NPs presented an average size of 139 ± 0.42 nm using electrophoretic light scattering (n = 3). Photomicrographs obtained by TEM showed homogeneous and spherical-shaped particles. The encapsulation efficiency was 99.99% for minocycline and the slow-release time was more than 72 h with pH-sensitive property. The in vitro skin adhesion experiment showed that the largest bioadhesive force is 0.35 N. Moreover, the hydrogel showed broad-spectrum antimicrobial and effective antibacterial ability when concentration of the ZnO NPs was over 0.2 µg/mL. The cell survival rates were more than 85% below 0.8 mg/L of ZnO NPs, which proved its low toxicity and high security.

Two new geranylphenylacetate glycosides from the barks of Cinnamomum cassia.

Two new glycosides, cinnacassides F (1) and G (2), with a rare geranylphenylacetate carbon skeleton, were isolated from the barks of Cinnamomum cassia, along with three known analogues, cinnacassides A (3), B (4) and C (5). The structures of the new compounds were elucidated on the basis of extensive NMR spectroscopic analyses and chemical method. Compounds 1-5 were investigated for their immunomodulatory activities, and compounds 1, 3 and 4 showed differential immunosuppressive activities against murine lymphocytes.

[Characteristics of dry matter and potassium accumulation and distribution in potato plant in semi-arid rainfed areas].

In 2010, a field experiment with potato (Solanum tuberosum) cultivar 'Xindaping' was conducted at the Dingxi Extension Center of Gansu Province, Northwest China, aimed to understand the accumulation and distribution patterns of dry matter (DM) and potassium (K) in the organs of potato plant in semi-arid rainfed areas. During the whole growth period of the cultivar, the DM accumulation in root, stem, and leaf all showed a unimodal curve, with the DM accumulation rate being leaf > stem > root, whereas the DM accumulation in whole plant and tuber was an S-curve. The maximum DM accumulation rate of the whole plant was higher than that of the tuber, and appeared 17 days earlier. The distribution of DM in different organs showed two turning points, i.e., during the tuber formation (TF) period and the tuber growth (TG) period. During TF period, the DM accumulation was the greatest in leaf, followed by in tuber. The TF period was also the DM balance period, which occurred 90 days after emergence. Before the DM balance period, the DM accumulation in tuber was lesser than that in root, stem, and leaf, and there was a positive correlation between the DM accumulation in tuber and in root, stem, and leaf. However, after the DM balance period, the DM accumulation in tuber was greater than that in root, stem, and leaf, and the correlation was negative. At seedling stage and in TF period, TG period, starch accumulation period, and maturity period, the DM accumulation in whole plant was 5%, 30%, 60%, 4% , and 1%, while that in tuber was 0,18% , 62 , 18% , and 2%, respectively. In the whole growth period, more than 50% of the DM was formed in TG period. The K concentration was the highest in stem and the lowest in tuber, though the K was mostly concentrated in root before the DM balance period. The K accumulation before the DM balance period was mostly in root, stem, and leaf, with the sequence of stem > leaf > root, but after the DM balance period, the K was mainly allocated in tuber, with >60% of the K accumulated in tuber in maturity period.