Six new quassinoids from Picrasma chinese P·Y. Chen and their cytotoxicity activity.

In the present study, six new compounds namely, picralactones CH (1-6) along with nine known compounds (7-15) were isolated from the branches and leaves of Picrasma chinese P.Y. Chen. Their structures were determined with the help of spectroscopic techniques such as NMR, HR-ESI-MS, UV, IR and CD. Cytotoxicity of all compounds was evaluated against MDA-MB-231, SW-620 and HepG2 human cancer cell lines. Compound 4 showed cytotoxic activities.

Two new oleanane triterpenes from Maytenus hookeri.

Two new triterpenes mayteneri A (1), mayteneri B (2), and seven known compounds (3-9) were isolated from stems of Maytenus hookeri Loes. The chemical structures of compounds 1 and 2 were established by 1D, 2D NMR, HRESIMS analysis, and calculating electronic circular dichroism (ECD). The structures of known compounds 3-9 were determined by comparison of their spectral with those reported. Compounds 4-7 showed significant inhibitory activity for NLRP3 inflammasome, with the IC50 values of 2.36-3.44 µM.

Three new diterpenoids isolated from Euphorbia nematocypha Hand.-Mazz and their anti-fungal activity.

Three new diterpenoids, named nematocynine A-C (1-3), together with twelve known compounds (4-15) were isolated from the aerial part of Euphorbia nematocypha Hand.-Mazz (Hereinafter referred to E. nematocypha). Their structures were elucidated by detailed spectroscopic analysis and comparison with literature data. In addition, all the compounds were tested for their anti-candida albicans activities used alone or in combination with fluconazole against sensitive strain and resistant strain in vitro. Wherein only compound 11 shows weak activity against candida albicans resistant strain (MIC50 = 128.15 µg/mL) when used alone. Compounds 1, 4, 7, 8, 9, 10, 12, 13 and 15 in combination with fluconazole showed potent anti-fungal activities (MIC50 = 15 ± 5 µg/mL, FICI = 0.05 ± 0.04) against the Candida albicans resistant strain SC5314-FR. The synergistic effects were weaker against the Candida albicans resistant strain SC5314-FR when the compounds 2, 3, 5 and 14 were combined with fluconazole (FICI = 0.16 ± 0.06).

Wulfenioidins D-N, Structurally Diverse Diterpenoids with Anti-Zika Virus Activity Isolated from Orthosiphon wulfenioides.

Eleven diterpenoids, wulfenioidins D-N (1-11), classified into five distinct carbon skeletons with one unreported framework, and four modified abietane diterpenoids were isolated from the whole plant of Orthosiphon wulfenioides. The structures and absolute configurations were characterized by spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism analyses. Compounds 3 and 5 exhibited activity against Zika virus (ZIKV) with EC50 values of 8.07 and 8.50 µM, respectively, and showed no significant cytotoxicity toward Vero cells at 100 µM. Western blot and immunofluorescence experiments showed that compounds 3 and 5 interfered with the replication of the ZIKV by inhibiting the expression of the ZIKV envelope (E) protein.

Chemical Constituents of the Branches and Leaves of Picrasma chinensis P.Y. Chen and Tyrosinase Inhibiting Activity.

One new alkaloid, picrasine A, two new quassinoids, picralactones A-B, together with eleven known compounds were isolated from Picrasma chinensis P.Y. Chen. The structures of these compounds were determined using 1D and 2D NMR, HR-ESI-MS, and IR spectroscopic data, and by comparison with published data. Some compounds were tested for tyrosinase inhibiting activity, however, none of them exhibited strong inhibitory effects.

Triterpene constituents from the fruits of Cyclocarya paliurus and their anti-HIV-1IIIB activity.

Four new norceanothane-type triterpenes, cyclopalin A-D (1-4), and sixteen known compounds (5-20) were obtained from the fruits of Cyclocarya paliurus. Their structures were determined by spectroscopic data, experimental electronic circular dichroism (ECD) and X-ray single crystal analyses. All isolated compounds were assayed for their anti-HIV-1IIIB activity. Compound 18 exhibited potent anti-HIV-1IIIB activity with an EC50 value of 1.32 µM (SI = 151.52).

Adaptive Changes in Hemoglobin Function in High-Altitude Tibetan Canids Were Derived via Gene Conversion and Introgression.

A key question in evolutionary biology concerns the relative importance of different sources of adaptive genetic variation, such as de novo mutations, standing variation, and introgressive hybridization. A corollary question concerns how allelic variants derived from these different sources may influence the molecular basis of phenotypic adaptation. Here, we use a protein-engineering approach to examine the phenotypic effect of putatively adaptive hemoglobin (Hb) mutations in the high-altitude Tibetan wolf that were selectively introgressed into the Tibetan mastiff, a high-altitude dog breed that is renowned for its hypoxia tolerance. Experiments revealed that the introgressed coding variants confer an increased Hb-O2 affinity in conjunction with an enhanced Bohr effect. We also document that affinity-enhancing mutations in the ß-globin gene of Tibetan wolf were originally derived via interparalog gene conversion from a tandemly linked ß-globin pseudogene. Thus, affinity-enhancing mutations were introduced into the ß-globin gene of Tibetan wolf via one form of intragenomic lateral transfer (ectopic gene conversion) and were subsequently introduced into the Tibetan mastiff genome via a second form of lateral transfer (introgression). Site-directed mutagenesis experiments revealed that the increased Hb-O2 affinity requires a specific two-site combination of amino acid replacements, suggesting that the molecular underpinnings of Hb adaptation in Tibetan mastiff (involving mutations that arose in a nonexpressed gene and which originally fixed in Tibetan wolf) may be qualitatively distinct from functionally similar changes in protein function that could have evolved via sequential fixation of de novo mutations during the breed's relatively short duration of residency at high altitude.

[Intervention of Tibetan medicine--twenty wei chenxiang pill on elevation of hypoxic pulmonary arterial pressure in rats].

OBJECTIVE: To investigate the role of Tibetan medicine-Twenty Wei Chenxiang Pill interfering with serum ET-1 level, in order to confirm that ET-1 is involved to the pathogenesis of hypoxic pulmonary hypertension. METHODS: 165 Wistar rats were randomly divided into high altitude control group,Tibetan medicine-Twenty Wei Chenxiang Pill group and plain control group. The physiological signal acquisition system was used to record pulmonary arterial pressure, and RV/(LV + S) ratio were caculated. Serum HIF-1alpha and ET-1 protein levels were determined by the method of ELISA, and ETA protein levels in lung tissue were determined by Western Blot method. RESULTS: Compared with the high altitude group,in the rats of Tibetan medicine-Twenty Wei Chenxiang Pill group,the pulmonary arterial pressure decreased significantly from the seventh day and the seventh day (P < 0.01), the RV/(LV + S) ratio and serum HIF-1alpha levels decreased significantly from the third day (P < 0.05 or P < 0.01), the serum ET-1 levels decreased significantly from the third day (P < 0.05 or P < 0.01), and the expression of ETA protein decreased significantly from the beginning (P < 0.01 or P < 0.001). CONCLUSION: ET-1 is one of the important factors causing pulmonary artery pressure increasing and right ventricular wall thickening, which plays a role in hypoxic pulmonary artery only involved in the early period hypoxia, but not in the later period. Tibetan medicine--twenty Wei Chenxiang Pill can prevent the pulmonary artery hypertension and the right ventricular wall thickening in rats, and its mechanism may be related to the direct inhibition of ET-1 and protein levels of ETA or the indirect downregulation of ET-1 level and ETA through inhibition of HIF-la level.

[Research on DNA fluorescence capillary biosensor marked by Goldview].

Goldview marked DNA fluorescence capillary biosensor was studied in the present paper. Based on fluorescence capillary analysis (FCA), the DNA biosensor uses capillary as immobilization carrier and detection carrier of DNA probe. Probes (20-mer-ssDNA) were immobilized on the inner wall of capillary by poly-l-lysine, and DNA fluorescence capillary biosensor (DNA-FCB) was made. After being hybridized with complementary target DNA and dyed by Goldview, the target DNA was qualified or quantified by detecting the fluorescence density of the Goldview using F-4500 spectrofluorometer. The sample volume was 12 microL. The concentration of the target DNA showed good linearity with the fluorescence intensity in the range of 0. 4-4 micromol x L(-1) (2.4-24 mg x L(-1)) (y = 65.911x + 3.9944, r = 0.9989). The RSD was lower than 3.5%. The concentration detection limit of the target DNA was 0.39 micromol x L(-1) (2.2 mg x L(-1)). The DNA-FCB can be used to qualify or quantify the target DNA. It's advantages are simplicity of manipulation, thimbleful of sample and reagent volumes, repeated use of capillary, and the lowest test cost. By using DNA-FCB to qualify the target DNA, we can consumedly decrease the pollution of the environment.