Screening of Polyphenols in Tobacco (Nicotiana tabacum) and Determination of Their Antioxidant Activity in Different Tobacco Varieties.

Tobacco (Nicotiana tabacum) is an herbaceous plant originating from South America and processed into cigarettes for consumption. Polyphenols are considered vital components of tobacco in view of their contribution to antioxidant properties. This study aimed to determine the phenolic compounds in different tobacco varieties by applying cold extraction with methanol and distilled water. The extracts were screened for phenolic compound diversity and distribution as well as their antioxidant potential in different tobacco varieties. The results showed that the methanolic extract of tobacco SP-28 exhibited the highest value in the total phenolic content (24.82 ± 0.07 mg GAE/gd.w.) and total flavonoid content (4.42 ± 0.01 mg QE/gd.w.), while the water extract of tobacco SN-2 exhibited the highest value in the total condensed tannin (1.12 ± 0.03 mg CE/gd.w.). The radical scavenging capacities of tobacco SP-28 were relatively high in DPPH (18.20 ± 0.01 mg AAE/gd.w.) and FRAP (3.02 ± 0.10 mg AAE/gd.w.), whereas the ABTS value was the highest in tobacco SN-2 (37.25 ± 0.03 mg AAE/gd.w.), and the total antioxidant capacity was the highest in tobacco SN-1 (7.43 ± 0.18 mg AAE/gd.w.). LC-ESI-QTOF-MS/MS identified a total of 49 phenolic compounds, including phenolic acids (14), flavonoids (30), and other polyphenols (5) in four different tobacco varieties. Tobacco SP-28 showed the highest number of phenolic compounds, especially enriched in flavones. Our study highlights the antioxidant potential of tobacco extracts and reveals the phenolic distribution among different tobacco varieties that could support tobacco utilization in different pharmaceutical industries.