Active Ingredients and Volatiles in Anoectochilus roxburghii Strains at Various Growth Stages

  Objective  Contents of active ingredients and volatiles in Anoectochilus roxburghii of different strains at different growth stages were determined.

  Method  SPME-GC-MS analysis was conducted to determine the chemical compositions in Fujian small-leaf Tuhaojin and large-leaf Dayuanbao A. roxburghii.

  Result  The highest total polyphenols of 265.07 mg·kg⁻¹ was found in Dayuanbao 18 months after planting, so were the total flavonoids of 32.68 mg·g⁻¹ and soluble sugars of 27.71 mg·kg⁻¹ in 12-month-old and soluble protein of 600.62 mg·g⁻¹ in 18-month-old Dayunbao plants. There were 6 alcohols, 8 aldehydes, and 4 ketones and 2-pentyl-furan identified with the greatest total amount in Dayunabao grown for 24 months. The volatile content of the 6-month-old tissue culture in Tuhaojin was merely 22.9% of the peak value in the respective cultivated seedlings, and in Dayuanbao, 16.7%. The odor activity value (OAV) and principal component analysis (PCA) concluded that (E)-2-hexenal, octanal, and nonanal were the major aromatic compounds in Tuhaojin, while 1-octen-3-ol, 3,7-dimethyl-1,6-octadien-3-ol, and β-ionone in Dayuanbao. The PCA and PLS-DA indicated that these volatiles could adequately distinguish A. roxburghii of different strains harvested at different times.

  Conclusion  Active ingredients and volatiles in A. roxburghii significantly varied by the strains and growth stages. It was plausible that a chemical analysis could suffice for quality control and authentication purpose on the products in commerce.