Phytochemical analysis and molecular identification of Magnolia hodgsonii (Hook. f. & Thomson) H. Keng from Northeast India

Abstract

Magnolia hodgsonii (Hook. f. & Thomson) H. Keng has been a traditionally important plant among the tribes of the Northeastern region of India. The present study aimed at the identification of this indigenous tree M. hodgsonii using DNA barcoding and analysis of their phytoconstituents using GC-MS and LC-MS/MS. The GC-MS analysis of petroleum ether extract (HSTP01_PET), detected 31 compounds including sesquiterpenes, monoterpenes, fatty acid methyl ester and lignan derivatives. Among them methyl 6,8-octadecadiynoate (33.58%), alpha-bisabolol (20.25%), 1h-cycloprop[e] azulene, decahydro-1,1,7-trimethyl (15.65%), cyclohexene, 3-(1,5-dimethyl-4-hexenyl)-6-methylene (13.44%) and furan 2,5-bis(3,4-dimethoxyphenyl) tetrahydro-3,4-di (1.12%). In LC-MS/MS analysis, both methanolic (HSTM-01) and aqueous (HSTA-01) extracts showed the presence of phenols, flavonoids, alkaloids, terpenes, coumarin and amino derivative compounds. Five bioactive compounds namely, 4-hydroxy 5 (3′, 4′ dihydroxyphenyl) valeric acid, Harmine, (+) – Catechin -3-O glucose, Lysine-Betaxanthin and Rheumlhasol A were detected in both the extracts. The rbcL and matK sequence was employed as a molecular marker in DNA barcoding. The phylogenetic tree was generated in MEGA X using the maximum likelihood method, and the robustness of the tree was evaluated using bootstrapping with 1000 replicates. This study revealed that M. hodgsonii is closely related to M. pterocarpa and M. liliifera. This is the first study of the chemical components of essential oil isolated from M. hodgsonii leaves. The use of molecular barcoding in identifying M. hodgsonii as well as the chemical composition may form an important marker in the compilation of future herbal pharmacopeia for its proper identification and medicinal use.