Cytotoxic sesquiterpene aryl esters from Armillaria gallica 012m

Objective:To study the chemical constituents of the EtOAc extract of Armillaria gallica 012m.Methods:The chemical constituents of the EtOAc extract of A.gallica 012m were isolated and purified by various column chromatography and their structures were elucidated on the basis of the 1D and 2D NMR spectroscopic and HRESIMS data.Cytotoxicity of all isolates against A549,HCT-116,M231 and W256 human tumor cells was determined by the MTT method.Results:A new sesquiterpene aryl ester,armimelleolide C(1),and eight known ones including armillarivin(2),melleolide F(3),6'-chloromelleolide F(4),melleolide(5),melleolide K(6),melledonol(7),13-hydroxydihydromelleolide(8),and armillane(9),were isolated from the EtOAc extract of A.gallica 012m.All isolates showed potential cytotoxic activities against at least one of the human cancer cell lines with IC_(50) values ranging from(3.17±0.54)to(17.57±0.47)μmol/L.Compound 1 showed significant inhibitory activity against M231 with an IC_(50) value of(7.54±0.24)μmol/L compared with paclitaxel as the positive control.Compounds 2,3,and 7,9 showed obvious inhibitory activity against HCT-116 and were better than that of the positive control.Conclusion:The chemical constituents including a new sesquiterpene aryl ester armimelleolide C(1)from the EtOAc extract of A.gallica 012m have a variety of structures and potential antitumor activities.

Preparation and Characterization of a Novel Benzimidazolium Bronsted Acid Ionic Liquid and Its Application in the Synthesis of Arylic Esters

A novel Brφnsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate （[Hebim]BF4） with functional benzimidazolium cation was synthesized and characterized by ^1H NMR, IR, MS spectra and elemental analysis. This novel ionic liquid was successfully used as dual solvent-catalyst for the synthesis of arylic esters. Higher yields were obtained in the presence of [Hebim]BF4 in comparison with other imidazolium ionic liquids because of the good solubility of the aromatic alcohols and aromatic carboxylic acids in [Hebim]BF4. The product could be separated conveniently from the reaction system, and the ionic liquid could be easily reused after removal of water under vacuum. After 10 times reuse, the selectivity of the ester was still 100%.

Structures and cytotoxicities of three new sesquiterpenes from cultures of Armillaria sp.

Three new sesquiterpene aryl esters,named 10-dehydroxy-melleoliede B(1),1-O-formyl-10-dehydroxy-melleoliede B(2)and 10-oxo-melleoliede B(3)together with six known ones(4-9),were isolated from the cultures of Armillaria sp.The structures of the new compounds were elucidated based on the extensive spectroscopic methods.Compounds 1,2,and 5-9 exhibited moderate cytotoxicities.

Fragmentation Mechanism of Trans-α-Aryl-β-enamino Esters

Electron impact induced fragmentation mechanisms of trans α aryl β enamino esters were investigated using mass analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data. It was found that the main characteristic fragmentations of compounds studied were: an odd electron ion M +· -EtOH was formed by losing a neutral molecule of ethanol; and the skeletal rearrangements took place; and the ring opening reaction happened after losing a carbon monoxide; and the typical McLafferty rearrangement underwent in ester group. The cyclization reaction caused by losing neutral molecule of TsNH 2 due to the ortho effects of substituted group of aromatic ring was also observed.