Identification of terpenoids volatilized from Thymus vulgaris L. by heat treatment and their in vitro antimicrobial activity

摘要

Enhanced antifungal activity by hot water treatment at 50 degrees C 20 s against Botrytis cinerea Pers. ex Fr., a gray mold pathogen was evaluated in thyme (Thymus vulgaris L.) Thymol, p-cymene, and gamma-terpinene were detected as the main volatile compounds in thyme plants. Emission of p-cymene and gamma-terpinene from thyme increased after treatment, whereas amount of thymol released did not change, suggested that existence of a thermo-dependent synthesis pathway of p-cymene and gamma-terpinene. Volatile p-cymene inhibited mycelial growth of pathogen at 0.50 mu L/ml, whereas gamma-terpinene had an inhibitory effect at 0.05, 0.10, and 0.50 mu L/ml. Transcript level of gamma-terpinene gene increased after 24 h of treatment. As a conclusion, heat treatment enhanced antifungal activity by volatile terpenoids synthesized by thermo-dependent synthesis pathway of them in thyme. (C) 2016 Elsevier Ltd. All rights reserved.