Quality Evaluation Of Tea Tree Hydrosol And Correlation With Separation Materials And Tea Tree Oil

Tea tree hydrosol(TTH)is the aqueous phase produced together with tea tree oil(TTO)in the steam distillation process of the twigs and leaves of Melaleuca alternifolia.It is considered to be useful in the treatment of skin diseases and widely used cosmetics and personal care products.Although many functions of TTH have been reported,there are still no reports on the qualitative and quantitative analysis and quality evaluation of the related products so far.Solid phase extraction(SPE)was used in the pretreatment of TTH because the concentration of its components was too low.The optimized results were obtained by using MCI gel as the enrichment material,ethyl acetate as eluent,TTH sample volume of 200 m L,and the elution volume of 8m L.Then,the correlation between TTH and thirteen materials was analyzed by spearman analysis.The enrichment effect of TTH was mainly related to the polarity,structure,pore size and specific surface area of the materials.The low polarity pore resin MCI gel with polystyrene as the basic structure had the best enrichment effect on the components in TTH.On the basis of the TTH pretreatment by SPE with MCI gel as packing,the qualitative and quantitative methods by GC-MS and GC-FID,and the holistic component features evaluation by fingerprinting of TTH were established and applied to the authentication and quality evaluation.In this study,thirteen compounds were identified and nine compounds,1,4-cineole(1),1,8-cineole(2),terpinen-4-ol(3),2-endo-hydroxy-1,4-cineole(4),trans-1,4-terpin(5),cis-1,8-terpin(6),trans-1,8-terpin(7),1S,2S,4S-trihydroxy-p-menthane(8)and 3,4-dehydroglobulol(9)were determined.TTH and TTO are the water phase and oil phase of distillate from steam distillation respectively.This study revealed the correlation between TTH and TTO from three aspects,namely,the characteristics of their respective components and cross components,the antibacterial activity and the structural correlation of compounds.TTH and TTO had three common components: 1,8-cineole,terpinen-4-ol and α-terpineol.Among them,terpinen-4-ol was the most abundant component in TTH and TTO,which played a major role in antibacterial activities.The major components of TTH and TTO had same skeleton structures,but different oxidation degree.Twelve separation materials were used to enrich TTH,and then 24 TTH extracts were obtained by 50% and 95% ethanol-water elution.The seven main components in TTH extract were determined by GC.Then the correlation between the components and antibacterial activity was studied by factor analysis and spearman correlation analysis.The results showed that the components in the extracts had strong inhibitory activity against gram-positive bacteria.Overall,this is the research on the chemical components and quality evaluation of TTH and correlation with separation materials and TTO,which supports its potential application in health care products.