基于GC-MS分析鼓槌石斛不同花期及不同部位挥发性成分

Volatile components of different periods and different parts of Dendrobium chrysotoxum based on GC-MS

关键词:  花香，鼓槌石斛，固相微萃取，花香释放规律

Key words:  floral scent, Dendrobium chrysotoxum, SPME, floral?fragrance?release?pattern

摘要:

为探究鼓槌石斛(Dendrobium chrysotoxum)开花时挥发性成分特点，采用固相微萃取(SPME) 结合气相色谱质谱联用(GC-MS)技术检测鼓槌石斛花蕾期、初花期、盛花期和末花期4个时期及盛花期唇瓣、萼片、花瓣和花蕊柱4个部位的挥发性成分，并对其进行分析比较。在鼓槌石斛4个时期共检测挥发性成分29种，由13种烯类、6种醇类、2种醛类、2种酯类、2种烷类、1种酚类、1种酸类和1种其他类组成，在鼓槌石斛盛花期4个部位中共检测挥发性成分39种，由15种烯类、9种醇类、4种烷类、3种酯类、3种酮类、2种醛类、2种其他类和1种酸类组成。结果表明：(1) 不同时期挥发性成分存在差异，在盛花期挥发性成分最多有22种，主要为烯类和酯类；(2) 醋酸辛酯、罗勒烯、(+)-α-蒎烯、(-)-β-蒎烯、月桂烯、d-柠檬烯和正辛醇这7种成分为鼓槌石斛中重要的挥发性成分，其中醋酸辛酯和罗勒烯在盛花期中释放量最高,分别占总含量的31.74％和24.98％，醋酸辛酯在花蕾、初花、盛花三个时期中都检测到且含量都较高，(+)-α-蒎烯、(-)-β-蒎烯、月桂烯、d-柠檬烯和正辛醇这5种挥发性成分仅在初花期和盛花期中检测到且随着花朵开放含量逐渐增加；(3)鼓槌石斛不同部位释放的挥发性成分种类和含量存在差异，在萼片中检测到的挥发性成分种类最多最复杂，共有29种，花瓣中的挥发性成分种类有20种，总含量最高，为5754.26 ng·g-1，主要挥发性成分醋酸辛酯仅在唇瓣中检测到；(4)鼓槌石斛在盛花期挥发性成分种类最多，含量最高，盛花期主要挥发性成分释放部位为花瓣和萼片。该研究结果将对鼓槌石斛花日化产业开发奠定理论基础。

Abstract:

In order to investigate the characteristics of volatile components in Dendrobium chrysotoxum during flowering, solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to detect the volatile components in four periods of D. chrysotoxum, namely, bud, primordial, full-flowering and final flowering, as well as in four parts of labellum, sepals, petals and pistil column during full-flowering. The volatile components were analyzed and compared. A total of 29 volatile components were detected in the 4 periods of D. chrysotoxum, consisting of 13 alkenes, 6 alcohols, 2 aldehydes, 2 esters, 2 alkanes, 1 phenol, 1 acid and 1 other class, and a total of 39 volatile components were detected in the 4 parts of D. chrysotoxum in full bloom, consisting of 15 alkenes, 9 alcohols, 4 alkanes, 3 esters, 3 ketones and 2 other classes. aldehydes, 2 others and 1 acid. The results were as follows： (1)There were differences in the volatile compositions in different periods, and there were 22 volatile compositions in the full bloom period, mainly alkenes and esters; (2) The seven volatile components, namely, octyl acetate, loreleiene, (+)-α-pinene, (-)-β-pinene, laurolene, d-limonene and n-octanol, were important volatile components in D. chrysotoxum. Among them, octyl acetate and loreleiene were the most released in the full-flowering period, which accounted for 31.74% and 24.98% of the total content, and the contents of acetic acid, octyl ester were detected in the three periods of buds, primordia and full bloom, and the content was higher, (+)-α-pinene, (-)-β-pinene, myrcene, d-limonene and 1-octanol were detected only in the early and full-flowering periods and their contents increased gradually with the opening of the flowers; (3) The types and contents of volatile components released from different parts of D. chrysotoxum also varied, with 29 types of volatile components detected in sepals, 20 types of volatile components in petals, with the highest total content of 5754.26 ng·g-1, and the main volatile component acetic acid, octyl ester was detected only in the labellum;(4) D. chrysotoxum have the most volatile constituents with the highest content in the bloom period, and the main volatile constituent release sites in the bloom period were the petals and sepals. The results of this study will lay a theoretical foundation for the development of D. chrysotoxum flower daily industrialization.