Effect of reactive oxygen species on 1,4-benzoquinone-induced mitophagy / 预防医学

Objective To investigate whether the metabolite of benzene, 1, 4-benzoquinone (1, 4-BQ) , can activate PINK1/Parkin-mediated mitocphagy and the role of reactive oxygen species (ROS) in 1, 4-BQ induced mitophagy in vitro. Methods Human promyelocytic leukemia cells HL60 were used as the test cells, and were divided into control group, 1, 4-BQ group (10 μM 1, 4-BQ treated cells for 24 h), NAC group (5 mM antioxidant N-acetyl cysteine treated cells for 24 h) and 1, 4-BQ+NAC group (5 mM NAC preincubated for 1 h prior to the treatment with 10 μM 1, 4-BQ for 24 h) . The ultra structure of the cells were observed by transmission electron microscopy (TEM), and the expression of mitophagy related protein LC3, PINK1 and Parkin were detected by Western blot, and the intracellular ROS content was determined by DCFH-DA staining. Results The mitochondria in the control group showed a normal rod-shaped structure with clear mitochondrial cristae, while in the 1, 4-BQ group, the mitochondria showed a swollen structure with less mitochondrial cristae, and typical double-membrane mitophagosomes were observed. LC3-Ⅱ/LC3-Ⅰ ratio, the expression of PINK1, Parkin protein and ROS content in 1, 4-BQ group were increased compared with the control group (P <0.05) , and this increase was markedly blocked by the co-treatment of 1, 4-BQ and NAC (P <0.05) . Conclusion The 1, 4-BQ can induce PINK1/Parkin-mediated mitophagy and ROS plays a significant role in 1, 4-BQ-induced mitophagy.

Chemical constituents from pods of Glycine max / 中草药

Objective: To investigate the chemical constituents from the pods of Glycine max. Methods: The chemical constituents were isolated by repeated silica gel chromatography, Sephadex LH-20 gel column chromatography, medium pressure column chromatography, and semi-preparative liquid chromatography. Their structures were elucidated by chemical properties and spectroscopic analyses. Results: Fourteen compounds were identified to be 4,4'-diphenylmethane-bis (ethyl) carbamates (1), 2,6-dimethoxy-1,4-benzoquinone (2), (+)-medioresinol (3), taraxerone (4), lupenone (5), 7,3',4'-trihydroxyflavone (6), coumestrol (7), indole-3-carboxylic acid (8), apigenin (9), phaseol (10), 7,4'-dihydroxyflavone (11), stigmasterol (12), β-sitosterol (13), and β-daucosterol (14). Conclusion: Compounds 1-5 are obtained from the pods of G. max for the first time, and compound 6 is obtained from this plant for the first time.

Cloning and expression analysis of MPBQ MT gene in safflower / 中草药

Objective: Safflower (Carthamus tinctorius) is an important natural source of vitamin E. 2-Methy-6-phytyl-1,4- benzoquinone methyltransferase (MPBQ MT) is a key enzyme in vitamin E synthesis pathway. MPBQ MT gene was cloned, bioinformatics was analyzed, and expression was analyzed to provide the foundation for the biosysthesis and regulation mechanism of vitamin E in safflower. Methods: According to the intermediate sequence obtained from the database of the safflower seed,MPBQ MT gene sequence was cloned by RT-PCR and RACE techniques, and the protein characteristics were analyzed using bioinformatics and constructing phylogenetic tree. The expression of MPBQ MT gene in the different development stages was analyzed using real time-PCR. Results: The full cDNA sequence of MPBQ MT gene was 1 392 bp, named CtMPBQ MT, contained an open reading frame (ORF, 1 038 bp), and encoded a protein of 345 amino acids with a predicted molecular mass of 38 900. The conserved structural domain analysis showed that it had the typical functional domains of SAM protein. Sequence alignment and phylogenetic tree analyses showed that the MT MPBQ gene had some homology with other amino acids, and among them CtMPBQ MT had 89% and 86% of consistency with MPBQ MT of Helianthus annuus and Lactuca sativa. The expression of CtMPBQ MT gene in safflower seeds at different development stages was determined by quantitative real-time PCR, it was found that the highest expression level of CtMPBQ MT gene was detected in 50 d after flowering. Conclusion: MPBQ MT gene of safflower is successfully cloned, analyzed, and expressed, meantime a basis for the study on matter in the synthesis and regulation of vitamin E is provided.

Quantitative HPLC Analysis and Extraction of 2,6-dimethoxy-1,4-benzoquinone from Ficus foveolata Stems

An antibacterial benzoquinone, 2,6-dimethoxy-1,4-benzoquinone, isolated from Ficus foveolata stems was used as a standard marker for establishment of quantitative HPLC analysis for the stem extracts of F. foveolata . The method utilized a TSK-gel ODS-80Ts column (5 microm, 4.6 x 250 mm) with the mixture of methanol and 5% acetic acid in water (24:76, v/v) as the mobile phase at a flow rate of 1 mL/min, and quantitative detection at 289 nm. The parameters i.e. linearity, intraday and interday precision, accuracy, specificity and sensitivity of the method were evaluated for method validation. The recoveries of the method were 99.5 - 103.6% and good linearity (R2 > or = 0.9999) was obtained. A high degree of specificity, sensitivity as well as repeatability and reproducibility (RSD less than 2 and 5%, respectively) were also achieved. Chloroform was served as the most suitable solvent for extraction of 2,6-dimethoxy-1,4-benzoquinone. The optimised sample preparation and HPLC method can be practically used in the routine quality control process of F. foveolata stem extracts.

Two novel compounds from Ardisia punctata Lindl / 药学学报

To study the chemical constituents of Ardisia punctata,compounds were isolated with a combination of multi-chromatography.Their structures were determined on the basis of spectral analysis and comparison to those of the known compounds.A 1,4-benzoquinone derivative and a alkylphenol were isolated from the petroleum ether extract of the roots of Ardisia punctata.Their structures were elucidated as 2-tridecyl-3-[(2-tridecyl-4-acetoxy-6-methoxy)-phenoxyl]-6-methoxy-1,4-benzoquinone (1) and 2-methoxy-4-hydroxy-6-tridecyl-phenyl acetate (2).The two compounds are both new.

A new sesquiterpene lactone from the roots of Lasianthus acuminatissimus / 药学学报

Aim To study the active constituents for the treatment of rheumatoid arthritis from the ethyl acetate extracts of the roots of Lasianthus acuminatissimus Merr. Methods Various chromatographic techniques were used to separate and purify the constituents. Their structures were established on the basis of 1D, 2D NMR and HRMS spectroscopic analyses and their preliminary evaluation of anti-inflammation effect on the release of β-glucuronidase was carried out. Results Eight compounds were isolated and identified as lasianthuslactone A ( 1 ) , codonolactone ( 2 ), 2, 5-dimethoxy-1,4-benzoquinone ( 3 ) ,uncargenin A (4) , nonadecyl alcohol (5) , 13-docosenoic acid (6) , tetracosanoic acid (7) and β-sitosterol (8). Compound 3 showed a significant inhibitory effect on release of β-glucuronidase rat polymorphous nuclear leukocytes activated by platelet activating factor (PAF). Conclusion Compound 1is a new one, the others were isolated from the plant for the first time and 3 is one of active antiinflammation compound in the plant.

Three new belamcandaquinones from Ardisia punctata / 药学学报

Aim To study the chemical constituents of Ardisia punctata. Methods Compounds were separated with a combination of multi-chromatography. Their chemical structures were determined on the basis of spectral analysis and single crystal X-ray diffraction. Results Three compounds were isolated from chloroform extract of the roots of Ardisia punctata. Their structures were elucidated as 2-tridecyl-3-[ (2-tridecyl-3-acetoxy-4-methoxy-6-hydroxy) -phenyl ] -6-methoxy-1,4-benzoquinone ( 1 ), 2-tridecyl-3-[ ( 2 -tridecyl-4,6-dihydroxy ) -phenyl ] -6 -methoxy-1,4-benzoquinone ( 2 ) and 2 -tridecyl-3 - [ ( 2 -pentadecyl-4,6-dihydroxyl)-phenyl]-6-methoxy-1,4-benzoquinone (3). Conclusion The three compounds are new1,4-benzoquinone derivatives.