Aromatic profiling of Murraya koenigii leaves by Thermal Desorption Gas chromatography-Mass Spectroscopy (TD-GC-MS)

Abstract

The germplasms of the Murraya koenigii were collected from Rajahmundry, Annur, Kollihills, Suvashini, Bhavanisagar, Karamadai (KMM5, KMM6, KMM7, KMM8 and KMM14) and the Kerala Agricultural University (KAU). The fresh leaves were analyzed for its volatile organic compounds by Thermal Desorption Gas chromatography–Mass Spectroscopy (TD-GC-MS) to obtain germplasm specific volatile fingerprinting. The correlation between genotypes based on volatile profiles has been analyzed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). A wide variety of volatile compounds identified in the eleven M. koenigii genotypes belongs to terpenoids, monoterpenes, sesquiterpenes, aldehyde, ketones, benzenes, azulenes and other minor compounds. The α-pinene and β-pinene content is high in Suvashini and Bhavanisagar (BSR) genotypes respectively. The monoterpenes such as γ-terpinene, α-myrcene and terpinolene are high in Karamadai variety (KMMK8), whereas caryophyllene content is high in the Rajahmundry. The results of PCA revealed that significant variances with 45.47% (PC 1) and 21.40% (PC 2). In AHC, the α-pinene and chloral hydrate forms the one major cluster. Additionally, α-fenchene and α-caryophyllene has observed forming second major cluster with significant magnitude. The cluster formed by sesquiterpenes are observed high in Annur (65.34%), followed by KMMK8 (48.01%), Kollihills (39.89%) and Rajahmundry (39.27%). The PCA and AHC combined with the fingerprint of TD-GC-MS have discriminated qualitative volatile profile and indicated that major changes VOCs emitted are highly attributed to the genetic factors.