Study On The Constituents From The Aerial Part Of Gentiana Scabra

The plant Gentianan scabra belongs to Gentiana genera of Gentianaceae family. Its root and rhizomes are widely used in traditional Chinese medicine for their remarkable bioactivities, such as antiinflammation, antitumer, antivirus and liver protection. Till now, people have paid more attention to the underground parts of the plant compared to the aerial parts. But the xanthones, flavaoids and triterpenoids, which are rich in the aerial part of the Gentiana genera, are reported to possess anti-inflammation, liver protection, antithrombotic, antitumer and immunity enhancement activities. For the purpose of making good use of the medicinal plant, the constituents of aerial parts of G. scabra have been systematically studied in this paper.The essential oil of the aerial parts of G. scabra was extracted by means of steam distillation. Thirty components are determined from the essential oil and fourteen of them are identified by GC-MS techniques, most of which are paraffin hydrocarbons.The constituents from the aerial parts of the plant are investigated. Twelve compounds (I～XII) are obtained by means of solvent partition and various column chromatography including preparative HPLC. On the basis of MS, 1D-NMR, 2D-NMR and physical properties, their structures are elucidated asβ-Amyrin acetate (I),β-Amyrin (II),β-Sitosterol (III), Uvaol (IV), Oleanolic acid (V), 6-Demethoxy-7-methylcapillarisn (VI), Cercosporin (VII), Apignenin (VIII), Mangiferin (IX), Isovitexin-7-O-glucoside (X), Isoorientin-4-O-glucoside (XI) and Apignenin-7-Oglucoside (XII). Compounds I～XII are firstly isolated from aerial parts of this plant while compound VI and VII are isolated from Gentianaceae family for the first time.HPLC quantitive analytical methods for mangiferin, oleanolic acid and gentiopicroside both in the aerial parts and underground parts of G. scabra are established with the above three constituents as reference compounds. The results show that the content of mangiferin and oleanolic acid are 0.39% and 0.35% respectively in aerial parts whilst are 0.0071% and 0.0093 % respectively in underground parts, but gentiopicroside cannot be detected in the aerial part and amounts to 1.27% in underground parts. This study reveals a great difference of the three effective constituents between the underground and the aerial parts, and so provides a theoretic reference for the further application of the plant.