Study On The Volatile Compounds Analysis Of Cupressus And Its Antifungal Activity

Cupressus is an evergreen tree belonging to the family Cupressaceae.Cupressus wood has balsamic and antiseptic properties.It is not only traditional high-quality materials and excellent landscaping trees,but also one of the spices commonly added in daily hygiene products.Therefore,the study on the volatile components and antifungal activity of Cupressus is of great significance for the rational development and utilization of Cupressus.The separation conditions,enrichment,structural identification,and content analysis of the volatile compounds in the powders of Cupressus wood are systematically studied in this paper.Besides,the antifungal components in the volatile compounds are screened and their antifungal properties are studied.The specific research contents and conclusions are as follows:1.A method was established for analyzing the volatile compounds in the powders of Cupressus wood by static headspace-gas chromatography-mass spectrometry(SHS-GC-MS).The conditions of extraction and GC-MS were systematically studied by box-behnken design based on single factor tests.Next,identification of volatile components was accomplished by mass spectrometry and retention index.Finally,the contents of volatile compounds were quantified through internal standard.An HP-5MS chromatographic column was chosen,and the oven temperature was programmed as follows: initial 40 °C with a 5 min hold,ramped to 95 °C at 4 °C min-1(held for 3 min),ramped to 120 °C at 3 °C min-1(held for 10 min),ramped to 165 °C at 2 °C min-1(held for 5 min).The optimal headspace parameters were: sample amount 0.9 g,equilibration time 30 min,equilibration temperature 128 °C.The results showed that 91 compounds were isolated and 60 structures were identified using the selected chromatographic separation condition,which accounting for 96.018% of the total volatile components.2.The antifungal components in the volatile compounds were identified.Five kinds of Cupressus wood powders with different origins and varieties were selected as the research objects.The contents of each component in the five types of Cupressus wood powders were obtained respectively by SHS-GC-MS.The two-sealed-base-plates method was used to test the suppressive effect of volatile compounds against Fusarium oxysporum f.sp.Cucumerinum,Colletotrichum gloeosporioides,Botrytis cinerea and Pleurotus ostreatus.Then by examining the correlation between the content of the main components in the powders of Cupressus wood and its antifungal rate.It was found that the contents of cedrol,?-Cedrene and ?-Cedrene were positively correlated with the inhibitory ratio.The antifungal activity of cedrol was verified in vitro.The results provide a certain experimental and theoretical basis for the comprehensive utilization of Cupressus wood powders.3.Antifungal activity of cedrol was assessed both in vitro and in vivo.The two-sealed-base-plates method was used to test the suppressive effect of cedrol ethanol solution against plant pathogenic fungi.In vivo study was conducted to investigate the effect of cedrol ethanol solution on the control of strawberry grey mould during storage.The results showed that the ethanol solution of cedrol had significantly inhibitory effects on mycelial growth of Fusarium oxysporum f.sp.Cucumerinum,Colletotrichum gloeosporioides,Botrytis cinerea.Moreover,it exhibited control efficacy of 70.21% against grey mould of strawberry.Therefore,cedrol has the potential to be developed as a new chemical fungicide.The results provide a certain experimental basis for the application of cedrol for crop protection.