Synthesis and Antimicrobial Characterization of Half-Calycanthaceous Alkaloid Derivatives.

A total of 29 novel tetrahydropyrroloindol-based calycanthaceous alkaloid derivatives were synthesized from indole-3-acetonitrile in good yields. The synthesized compounds were evaluated against nine strains of bacteria and a wide range of plant pathogen fungi. Bioassay results revealed that majority of the compounds displayed similar or higher in vitro antimicrobial activities than the positive control. The biological activities also indicated that substituents at R4 and R5 significantly affect the activities. Notably, compound c4 was found to be most active among the tested calycanthaceous analogues and might be a novel potential leading compound for further development as an antifungal agent. The results could pave the way for further design and structural modification of calycanthaceous alkaloids as antimicrobial agents.

Quinone derivatives from the genus Rubia and their bioactivities.

The extracts and phytochemicals of the genus Rubia have drawn much attention due to their potent effects; among them, naphthoquinone and cyclopeptide derivatives, with significant biological activities, have great potential to be developed to new drugs. This review updates and compiles a total of 142 quinone derivatives including anthraquinone and naphthoquinone derivatives, occuring in twelve Rubia species. These compounds were listed together with their sources, melting points, bioactivities, as well as 112 corresponding references. Furthermore, the structureactivity relationships of these quinone derivatives were discussed.

Protection of a new heptapeptide from Carapax trionycis against carbon tetrachloride-induced acute liver injury in mice.

A new heptapeptide GAGPHGG (OC1) was isolated from Carapax trionycis which was a traditional Chinese medicine (TCM) used for treatment of hepatic diseases. The structure of OC1 was characterized by MS, NMR techniques, together with amino acid sequence analysis. The hepatoprotective activity of OC1 was evaluated in vivo using the CCl4-induced acute liver injury model. Combining the pathological examination and the biochemical assays, OC1 (0.34 mg/kg, hypodermic injection) displayed better hepatoprotective effect than bifendate (100 mg/kg, intragastric administration) against the acute liver injury induced by carbon tetrachloride (CCl4) in mice. Compared with the model group, OC1 could significantly suppress the increase of serum level of aminotransferase (alanine transaminase (ALT) and aspartate aminotransferase (AST)), decrease the formation of malondialdehyde (MDA) and elevate the activity of glutathione peroxidase (GSH-Px) in liver (p<0.01). And the acute toxic test showed that median lethal dose (LD50) of OC1 exceeded 6.8 mg/kg, via hypodermic injection in mice.

Enhanced desulfurizing flotation of coal using sonoelectrochemical method.

Enhanced desulfurizing flotation of low sulfur coal was investigated using sonoelectrochemical method. The supporting electrolyte used in this process was sodium chloride and the additive was anhydrous ethanol. The effects of treatment conditions on desulfurization were studied by a single-factor method. The conditions include anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature, sonoelectrolytic time and coal sample granulometry. The optimal experimental conditions achieved for anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature and sonoelectrolytic time are 1.7 mol L(-1), 5.1×10(-3) mol L(-1), 10 V, 70 °C, 50 min achieved for a -0.18 mm coal sample. Optimal conditions cause a sulfur reduction of up to 69.4%. The raw and treated coals were analyzed by infrared spectroscopy and a chemical method. Pyritic sulfur, organic sulfur, ash as well as moisture are partially removed. The combination of high sulfur reduction, high yield, as well as high ash reduction was obtained in the newly developed method of enhanced flotation by sonoelectrochemistry. Ultrasound irradiation promotes electron transfer efficiency and increases clean coal yield.