Volatiles from Solanum paniculatum Leaves in Response to Mechanical Damage

Abstract

The yield of the essential oil obtained by hydrodistillation of intact S. paniculatum leaves was 0.04%, and that of mechanically damaged leaves was 0.05%. The chemical profile obtained by GC of essential oil from intact leaves indicated a major peak at 31.1 min (54.3%), identified as E-nerolidol based on the GC-MS data. Besides nerolidol, three other compounds were identified: verbenene (1.1%), ionone (4.3%), and tricosane (38.3%), making up 98.0% of the total composition (Table 1). Along with E-nerolidol (27.3%), also found in the intact leaves, seven more compounds were identified in the essential oil from mechanically damage leaves: spathulenol (0.3%), dillapiole (13.1%), epi--muuralol (1.1%), -eudesmol (1.1%), -cadinol (3.1%), oleic acid (2.7%), and hexacosane (14.9%), making up 63.6% of the total composition. An unexpected finding was the presence of dillapiole in high amounts, since production of phenylpropanoids has been identified in plants as an induced resistance mechanism in response to abiotic and biotic stresses [11]. The results of our experiment demonstrate that S. paniculatum leaves respond very clearly to mechanical damage by biosynthesizing several stress-related volatile compounds,