INFLUENCE OF ALTITUDINAL AND LATITUDINAL VARIATION ON THE COMPOSITION AND ANTIOXIDANT ACTIVITY OF POLYPHENOLS IN NICOTIANA TABACUM L. LEAF
Polyphenols content and its antioxidant activities of methanol extracts of Nicotiana tabacum L. leaf from different altitude (from 70 m to 2100 m) and latitude (from 23.26° N to 34.61° N) were studied. The compositions of polyphenol were detected by UPLC-MS, and the total polyphenols content (TPC) and total flavonoids content (TFC) were measured by spectroscopic methods. The antioxidant activity assays were measured by the bleaching of the 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH), reducing power ability (RP), and ferric reducing antioxidant power (FRAP). Chlorogenic acids (CQAs, including 5-O-Caffeoylquinic acid, 4-O-Caffeoylquinic acid and 3-O-Caffeoylquinic acid), rutin, and amount phenolic compounds (APC, CQAs and rutin) showed high significant positive correlation with altitude, besides, TPC and TFC were significant positive correlation with altitude. Otherwise, the results of them with latitude were almost no correlation, while TPC was significant negative correlation with latitude. The higher altitude of extract of tobacco sample the stronger antioxidant capacity was, but there was little relationship with the latitude. The compositions of polyphenol were various from different altitude, and there was a significant positive correlation between the altitude and rutin proportion. Based on the molecular structures, it’s probably because the UV absorbing ability and antioxidant activity of rutin are better than these of CQAs.