[Identification and quality evaluation of Cistanche deserticola from different production areas based on DNA...

Cistanche deserticola(Orobanchaceae) has both medicinal and dietary properties and is cultivated on a large scale in Inner Mongolia, Ningxia, Gansu, Qinghai, and Xinjiang. In this study, 37 batches of cultivated C. deserticola samples were collected from five production areas. All samples were identified and differentiated based on the internal transcribed spacer 2(ITS2) sequence. An ultra-performance liquid chromatography( UPLC) method was established to simultaneously determine seven phenylethanoid glycosides, one iridoid glycoside, and two phenolic acids. This method was subsequently applied to the quality analysis and fingerprint comparison of the samples. The results of DNA barcoding identification showed that all 37 samples were authenticated as C. deserticola by the ITS2 sequence, and two single-nucleotide polymorphism(SNP) loci were identified for the first time, which may serve as potential molecular markers to distinguish samples from Inner Mongolia from those originating in other production areas, reflecting the genetic characteristics of the geo-authentic medicinal materials. The results of UPLC determination showed that the content of seven phenylethanoid glycosides in the 37 batches of cultivated C. deserticola was as follows: echinacoside, 0. 31-72. 56 mg·g~(-1); cistanoside A, 0-5. 55 mg·g~(-1); tubuloside A, 0-3. 74 mg·g~(-1); acteoside, 0-45. 34 mg·g~(-1); isoacteoside, 0. 07-5. 60 mg·g~(-1); 2'-acetylacteoside, 0-73. 89 mg·g~(-1); and tubuloside B, 0-11. 82 mg·g~(-1). The content of the iridoid glycoside, geniposidic acid, ranged from 0. 04 to 2. 72 mg·g~(-1), and the content of two phenolic acids, chlorogenic acid and caffeic acid, ranged from 0. 17 to 3. 29 mg·g~(-1) and 0. 28 to 1. 93 mg·g~(-1), respectively. The chemical composition of samples from different batches fluctuated significantly and did not show a consistent correlation with the production area. Moreover, the total content of echinacoside and acteoside in one batch from each of Inner Mongolia, Gansu and Qinghai was lower than the standard specified in the Chinese Pharmacopoeia. The postharvest processing methods might be one of the reasons for this phenomenon. The standardization of production procedures for C. deserticola is crucial for achieving stable and controllable quality for both medicinal and dietary use. This study provides guidance for the formulation of relevant quality standards and promotes the development of the C. deserticola comprehensive health industry.