Analysis of volatile oil in Rhizoma Ligustici Chuanxiong-Radix Paeoniae Rubra by gas chromatography-mass spectrometry and chemometric resolution

Aim:To analyze the volatile chemical components of the herbal pair RhizomaLigustici Chuanxiong-Radix Paeoniae Rubra(RLC-RPR)and compare them withthose of each of the herbs alone.Methods:Gas chromatography-mass spectrom-etry(GC-MS),a chemometric resolution technique using the heuristic evolvinglatent projections(HELP)method,and the overall volume integration methodwere used.Results:In total,52,38,and 61 volatile chemical components in RLC,RPR,and RLC-RPR essential oils were determined,respectively,accounting for95.14%,95.19%,and 89.68% of the total contents of essential oil of RLC,RPR,andRLC-RPR,respectively.The main volatile chemical components werebutyldienephthalide(20.65%)and ligustilide(50.15%)for RLC;and n-hexadecanoicacid(20.18%),[Z,Z]9,12-octadecadienoic acid(30.11%),2-hydroxy-benzaldehyde(17.08%)for RPR,and butyldienephthalide(14.80%),and ligustilide(38.91%)forRLC-RPR.The main volatile chemical components of RLC-RPR were almost thesame as those of RLC,but the relative amounts were altered.Conclusion:Thenumber of volatile chemical components in RLC-RPR was almost equal to the sumof the number in the 2 constituent herbs,but the relative amounts were altered.Furthermore,an acid-base reaction takes place during the process of decoctingthe herbs.The data gathered in this study may be helpful for understanding thesynergistic nature of this herb pair in traditional Chinese medicine.