Antibacterial Aromatic Sesquiterpenes from the Leaves of Nicotiana tabacum

Two new aromatic sesquiterpenes, 1-isopropyl-5-methoxy-3,7-dimethylnaphthalene ( 1 ) and 3-hydroxymethyl-1-isopropyl-5-methoxy-7-methylnaphthalene ( 2 ), as well as five known sesquiterpenes ( 3–7 ), were isolated from the leaves of Nicotiana tabacum (a mutant tobacco for solanesol synthesis gene knockout by CRISPR-Cas9 gene editing). Their structures were determined by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were tested for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1 and 2 showed good inhibition with IZD of 12.8 ± 2.0 and 15.2 ± 2.2 mm, respectively. In addition, compounds 1 and 2 have a weak floral fragrance, and they have the potential for use as an essence for cigarettes.