Seasonal Influence on Volatile Organic Compounds from Flowers and Leaves of Lepechinia mutica Extracted by SPME-GC-MS

<i>Lepechinia mutica,</i> an endemic species of the Ecuadorian Andes, was studied to identify the seasonal variation in volatile organic compounds emitted from leaves and flowers in winter and summer using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). A total of 101 and 100 volatile compounds were identified in flowers and leaves, respectively. The main compounds in flowers were β-phellandrene (7.81-17.74%), dictamnol (3.57-31.89%) and 9-epi-(E)-caryophyllene (3.93-14.37%), while in the leaves, they were dictamnol (9.85-34.64%), (Z)-β-ocimene (1.24-29.24%) and δ-3-carene (1.14-11.51%). This is the first report of enantiomeric separation in <i>L. mutica</i> using a capillary column with 2,3-diethyldecyl-6-tert-butyl-dimethylsilyl-β-cyclodextrin, revealing three enantiomerically pure compounds as (<i>S</i>)-(-)-β-pinene, (1<i>S</i>,3<i>R</i>)-(+)-δ-3-carene and (<i>S</i>)-(+)-linalool, while (+) (-) α-pinene, (+) (-) δ-cadinene and (+) (-) α-muurolene were found as racemic mixtures. Principal component analysis confirmed distinct chemical profiles between plant parts and seasons. This result has important implications for the future highlighting its potential as a source of seasonally variables components with applications in fragrance and phytotherapy.