A new resorcylic acid lactone from the endophytic fungus Chaetosphaeronema sp.

A new 14-membered resorcylic acid lactone (RAL14), chaetolactone A (1), along with three known ones (2-4), was obtained from the fermentation of the soil-derived fungus Chaetosphaeronema sp. SSJZ001. Their structures were established based on extensive spectroscopic data analyses (UV, IR, HRESIMS, 1D, and 2D NMR),13C NMR chemical shifts calculations coupled with the DP4+ probability method, theoretical calculations of ECD spectra, as well as X-ray diffraction analysis. All compounds were evaluated for their cytotoxic effects against A549, HO-8910, and MCF-7 cell lines.

Lewis Acid Mediated Conjugate Addition of Isocyanides to ß-Hydroxy-α-diazo Carbonyls: Synthesis of ß-Carboxamido-α-diazo Carbonyl Compounds.

A Lewis acid mediated conjugate addition of isocyanides to ß-hydroxy-α-diazo carbonyls has been developed for the first time. The reaction realizes the efficient construction of quaternary carbon centers and provides a novel and efficient strategy for the synthesis of ß-carboxamido-α-diazo carbonyls that would be otherwise difficult to form in a single step. Further applications, including synthesis of methylenecyclohexane, spiro-ß-lactam, and nitrogen-bridged tricyclic ß-lactam, demonstrated the tremendous potential of the coupling reaction.

Visible Light-Induced Coupling Cyclization Reaction of α-Diazosulfonium Triflates with α-Oxocarboxylic Acids or Alkynes.

A photocatalyst-free radical cleavage of α-diazo sulfonium salts has been developed for the first time. The reaction provides an efficient method for the generation of diazomethyl radicals from α-diazosulfonium triflates under photochemical conditions. Utilizing the in situ generated diazomethyl radicals as key intermediate, the coupling cyclization reaction of α-diazosulfonium triflates with α-oxocarboxylic acids or alkynes has been achieved. The method affords a diverse set of important 2,5-disubstituted 1,3,4-oxadiazoles and 3,5-disubstituted-1H-pyrazoles with excellent regioselectivity in a single step. A reaction mechanism involving a radical pathway was further supported by control experiments and DFT calculations.

NaN(SiMe3)2/CsTFA Copromoted Aminobenzylation/Cyclization of 2-Isocyanobenzaldehydes with Toluene Derivatives or Benzyl Compounds: One-Pot Access to Dihydroquinazolines and Quinazolines.

A NaN(SiMe3)2/CsTFA copromoted aminobenzylation/cyclization reaction of 2-isocyanobenzaldehydes with toluene derivatives or benzyl compounds has been developed. The reaction works with a broad range of toluene derivatives and benzyl compounds, and provides a simple and efficient strategy for the synthesis of 4-benzyl-substitued dihydroquinazoline and quinazoline derivatives from easily available acyclic starting materials in a single step. Further applications, including synthesis of quinazoline, dihydroindolo[1,2-c]quinazoline, and dihydro-8H-isoquinolino[2,3-c]quinazoline, demonstrated the tremendous potential of the tandem reaction.

Silver-Catalyzed Cascade Cyclization Reaction of Isocyanides with Sulfoxonium Ylides: Synthesis of 3-Aminofurans and 4-Aminoquinolines.

A silver-catalyzed cascade cyclization reaction of isocyanides with sulfoxonium ylides has been developed for the first time. This reaction provides a new and efficient method for the construction of highly functionalized 3-aminofurans and 4-aminoquinolines from readily available starting materials in a single step.

Zn(OAc)2-catalyzed tandem cyclization of isocyanides, α-diazoketones, and anhydrides: a general route to polysubstituted maleimides.

A novel Zn(OAc)2-catalyzed three-component tandem cyclization reaction of isocyanides, α-diazoketones and anhydrides has been developed. The reaction demonstrates the wide scope of substrates and provides a novel and efficient strategy for the synthesis of polysubstituted maleimides from readily available substrates in a single step.

Effects of Zhaoyangwan on chronic hepatitis B and posthepatic cirrhosis.

AIM: To study the therapeutic effects of zhaoyangwan (ZYW) on chronic hepatitis B and hepatic cirrhosis and the anti-virus, anti-fibrosis and immunoregulatory mechanisms of ZYW. METHODS: Fifty cases of chronic hepatitis B and posthepatic cirrhosis with positive serum HBsAg, HBeAg, anti-Hbc and HBV-DNA were divided randomly and single-blindly into the treatment group (treated with ZYW) and the control group (treated with interferon). After 3 month treatment, the effects of the treatment group and the control group were evaluated. RESULTS: The serum ALT normalization was 83.3% (30/36) in the treatment group and 85.7% (12/14) in the control group, with no significant difference (chi2=0.043, P>0.05). After the course, the negative expression rates of the serum HBV-DNA and HBeAg were 44.4% (16/36) and 50% (18/36) in the treatment group, and 50% (7/14) and 50% (7/14) in the control group, respectively, with no significant difference (chi2=0.125, chi2=0.00, both P>0.05). Negative HBsAg and positive HBsAb appeared in 4 cases of the treatment group and 1 case of the control group. Serum anti-HBc turned negative in 6 cases of the treatment group and 1 case of the control group, respectively. After the ZYW treatment, serum CD3+, CD4+, CD8+, CD4+/CD8+ and NK cell activation were significantly increased. Only serum CD3+ and NK cell activation were significantly increased in the control group with a significant difference between the two groups. The serum C4, C1q, C3, B and C9 were significantly increased in the treatment group. In the control group only the serum C4 was increased. The concentration of serum interferon had no change after treatment with ZYW, while it was significantly increased in the control group after treatment with interferon. The ultrastructure of the liver restored, which helped effectively to reduce the degeneration and necrosis of hepatic cells,infiltration of inflammatory cells and hepatic cirrhosis. CONCLUSION: ZYW is a pure Chinese herbal medicine. It can exert potent therapeutic effects on chronic hepatitis B and posthepatic cirrhosis. ZYW has similar therapeutic effects to those of interferon. It is cheap and easily administered with no obvious side-effects. It can be widely used in clinical practice.