Isoindolinone alkaloid compound as well as preparation method and application thereof

The invention discloses an isoindolinone alkaloid compound as well as a preparation method and application thereof, and relates to the technical field of medicines. Four isoindolinone alkaloid compounds, namely a compound A, a compound B, a compound C and a compound D, are separated from a tremella aurantialba fermentation product, and the compounds are determined to be capable of remarkably inhibiting alpha-glucosidase and inhibiting conversion of oligosaccharide into glucose through corresponding nuclear magnetism, mass spectrum, infrared, ultraviolet and other data. Alpha-amylase is significantly inhibited, and carbohydrates in food are significantly inhibited from being decomposed into oligosaccharides, so that the content of glucose in blood is reduced, and significant activity for treating diabetes mellitus is shown. The isoindolinone alkaloid compound as well as the preparation method and the application thereof can be obtained. 异吲哚啉酮生物碱类化合物及其制备方法和应用，涉及医药技术领域。本发明从一株金耳菌发酵产物中分离得到化合物A、化合物B、化合物C和化合物D共4种异吲哚