Influence of altitudinal and latitudinal variation on the composition and antioxidant activity of polyphenols in Nicotiana tabacum L. leaf

This present comparative study was to investigate the influence of different altitude and latitude on the polyphenols, composition and its antioxidant activity in Nicotiana tabacum L. leaf. Polyphenol content and its antioxidant activities of methanol extracts of Nicotiana tabacum L. leaf from different altitude (70 m to 2100 m) and latitude (23.26 degrees N to 34.61 degrees 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 DPPH radical, reducing power ability, and ferric reducing antioxidant power. Results showed that chlorogenic acids (CQAs, including 3-CQA, 4-CQA and 5-CQA), rutin, and amount phenolic compounds (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 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. These preliminary findings demonstrated that influence of altitude on the content of individual polyphenol, TPC, TFC and antioxidant activities was significant, while the relationship with latitude was not significant overall.