基于香气嗅闻和分子对接技术解析贵州烟叶蜜甜香特征香气OA

[Objective]To explore the key aroma substances related to the honey-sweet aroma characteristic in the mainstream smoke of Guizhou tobacco leaves,and to verify the interaction between these aroma substances and olfactory receptors.[Methods]The aroma components in the mainstream smoke of a total of 8 unblended cigarette samples from honey-sweet aroma-producing regions and non-honey-sweet aroma-producing regions were analyzed qualitatively and quantitatively using gas chromatography-mass spectrometry-olfactometry(GC-MS-O),along with aroma description and aroma intensity evaluation.Based on the sensory descriptions and aroma intensities obtained from olfactometry,7 aroma substances that make significant contributions to the honey-sweet aroma characteristic were selected for aroma recombination verification.Additionally,molecular docking technology was employed to simulate the interaction between aroma substance molecules and olfactory receptors.[Results](1)A total of 146 volatile chemical components were detected in the smoke,among which 76 could be identified by olfaction.The aroma characteristics mainly include honey-sweet,caramel-sweet,floral,fruity,roasted,hay-like,and milk-like aromas,etc.(2)2,3-pentanedione,phenylacetic acid,phenethyl acetate,phenethyl alcohol,ethyl phenylacetate,α-ionone,geranylgeraniol,3-methyl-2-cyclopentenone,and methylcyclopentenolone were selected for aroma recombination to reproduce the honey-sweet note in cigarette smoke.(3)Molecular docking results demonstrated that all ligands could bind effectively to the olfactory receptor OR1A1,with binding energies all≤-4.2 kcal/mol.Among these ligands,geranylgeraniol exhibited the lowest binding energy(-6.1 kcal/mol),and its binding to the receptor was mainly mediated by hydrophobic interactions.The amino acid residue Asn292 functioned as a core hydrogen-bonding site,which could mediate the specific binding of 2,3-pentanedione,ethyl phenylacetate,phenethyl alcohol,and phenylacetic acid to the OR1A1 receptor through hydrogen bonds.In addition,ethyl phenylacetate was capable of forming hydrogen bonds with four amino acid residues(Asn292,Arg122,Thr239,and Ser242)of the OR1A1 receptor,with a corresponding binding energy of-5.1 kcal/mol.