Phytochemicals in leaves and extracts of the variety “Plovdiv 7” of Bulgarian oriental tobacco (Nicotiana tabacum L.)

Abstract

This study aims to identify and analyze the non-volatile fraction (chemicals, polyphenols, phenolic acids, flavonoids, and triterpenes) and volatile fraction (essential oil and crude extracted aroma fractions) present in the leaves of “Plovdiv 7” oriental tobacco variety (N. tabacum L.). The results show that the nicotine content in leaves reaches 2.3% (DW) and chemicals such as betulin (2340.7 g/g), carnosic acid (845.2 µg/g) and ursolic acid (596.0 µg/g) (595.95 g/g ), are also present. In terms of free phenolic acids, chlorogenic acid (2545.0 g/g), ferulic acid (1561.8 g/g), and vanillic acid (4461.9 g/g) are found to be dominant. The flavonoid profile is dominated by myricetin (134.2 g/g), quercetin (334.1 g/g), apigenin (493.0 g/g) and luteolin (445.6 g/g). In the volatile fraction, nineteen volatile components were identified (92.3%) where (E)-phytol (53.4%) was the major compound followed by solanone (6.8%), cis-5-butyl-4-methyldihydrofuran-2(3H)-one (6.4%) and dihydro-β-ionone (5.2%). In addition, the antimicrobial activity of “Plovdiv 7” tobacco leaf aroma extracts (concrete and resinoid extract) are tested against nine microbial strains. The results show a weak antimicrobial activity against Staphylococcus aureus and Bacillus subtilis bacteria, whereas no activity is recorded for the other seven microbial strains tested.