Coal spontaneous combustion is an extremely complicated physical and chemical changing process. In order to improve the indicator gases detection technology and coal spontaneous combustion monitoring, a novel forecast method for toxic gases emission from coal oxidation at low temperature is presented in this paper. The experiment system is setup combined with frequency-domain terahertz technology and coal temperature programming device. The concentration curves of carbon monoxide and sulphur dioxide gases from coal spontaneous combustion are estimated according to molecule terahertz spectra. The influences of coal rank and oxygen supply on coal spontaneous combustion characteristics are discussed. Both carbon monoxide and sulphur dioxide gases absorption spectra show the characteristic equi-spaced absorption peaks. Results demonstrate that under the condition of lean oxygen, there exists a critical oxygen concentration in the process of coal oxidation at low temperature. Comparing with Fourier infrared spectrum testing, the presented method is highly accurate and more sensitive, especially suitable for early-stage monitoring of the indicator gases produced by coal spontaneous combustion.
The genus Neolitsea (Lauraceae) contains over 85 species distributed around the world. These plants have been found to be rich in sesquiterpenes, triterpenes, steroids, and alkaloids. This review summarizes the phytochemical progress and list of all the constituents isolated from the genus Neolitsea over the past few decades. Some biological activities of compounds isolated from this genus are also included.
Exposure of Arabidopsis leaves to cadmium (Cd) stress led to an increase in the level of extracellular ATP (eATP). And, Cd stress also caused significant increases in lipid peroxidation and the activities of lipoxygenase (LOX) and antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT). Treatment of Arabidopsis leaves with β,γ-methyleneadenosine 5’-triphosphate (AMP-PCP), which serves as a competitive inhibitor of eATP, dampened the Cd-induced increases of lipid peroxidation and the activities of LOX and antioxidant enzymes. Under Cd stress, the leaves of dorn 1-3 mutant showed lower levels of lipid peroxidation and activities of LOX and antioxidant enzymes compared with those of wild type plants. These results suggest that the changes in lipid peroxidation and activities of LOX and antioxidant enzymes under Cd stress could be associated with eATP.
A new taxoid metabolite with an unusual double bond between C-13 and C-14 was isolated from the methanol extract of the hard wood of Taxus cuspidata. The structure was established as 2α,5α,7β ,9α,10β ,13β -hexaacetoxy-11β -hydroxyl-19β -benzoxytaxa-4(20),13-dien- 12,16-epoxide (1), named 5,13-diacetyltaxinine M-13-enol, on the basis of spectral analysis including 1H NMR, 13C NMR, HMQC, HMBC, NOESY and confirmed by HR-FAB-MS.
Structural modifications were performed on isoalantolactone in an effort to find compounds with potential anticancer activity. Seven previously unknown adducts of active methylene compounds with isoalantolactone were synthesized by the Michael reaction. Moreover, four derivatives of aryl-substituted isoalantolactone were prepared by the Heck reaction. All synthetic products were evaluated for toxic activities against three different hepatoma cell lines, Bel-7402, SMMC-7721, and Hep G2. Products prepared through the Heck reaction and 3a,b show potential antiproliferative activity against the Hep G2 cell.
The Chloranthaceae is a small family with only four genera (Ascarina, Chloranthus, Hedyosmum, Sarcandra), of which nearly 70 species are distributed around the world. Chemical constituents in Chloranthaceae plants, especially sesquiterpenes, have attracted a great deal of attention in recent 5 years. Many characteristic constituents of this family may be responsible for anti-microbial, anti-tumor and other activities. In order to provide information for the future research, the structures and biological activities of the known constituents from the plants of Chloranthaceae have been reviewed in this article.
The aim of this study was to determine the effects of Jinniu Capsule on methamphetamine (METH)-induced conditioned place preference (CPP) in rats and identify the underlying mechanisms. An intraperitoneal injection of 3 mg/kg METH was used for CPP training in rats. The effects of Jinniu Capsule following a single dose on rat CPP and repeat dosing on METH withdrawal were evaluated. Western Blot analysis was used to measure protein expression of the PI3K-AKT-mTOR signaling pathway to determine the mechanisms of Jinniu Capsule. A single dose of Jinniu Capsule did not influence METH-induced CPP in rats. However, repeat dosing for 7 days significantly promoted METH withdrawal. Furthermore, METH withdrawal activated the PI3K-AKT-mTOR signaling pathway phosphorylation cascade, and Jinniu Capsule partly blocked this cascade. Jinniu Capsule demonstrated potential in promoting METH withdrawal in a rat CPP model, which may be related to its influence on the PI3K-AKT-mTOR signaling pathway.