Chemical compositions, HPLC/MS fingerprinting profiles and radical scavenging properties of commercial Gynostemma pentaphyllum (Thunb.) Makino samples

Jiaogulan, Gynostemma pentaphyllum (Thunb.) Makino, is one of the well-known botanical ingredients for functional foods and beverages. The present study developed a simple, rapid and effective HPLC procedure for simultaneous quantification of rutin and quercetin in jiaogulan. This study also investigated the chemical compositions including total phenolic contents (TPC), total flavonoid contents (TFC) and total saponin contents (TSC), and HPLC/UV/MS fingerprinting profiles of eleven commercial jiaogulan samples. In addition, the scavenging capacities against 2,2-diphenyl-1-picryhydrazyl (DPPH) and hydroxyl (HOSC) radicals were studied. The eleven jiaogulan samples had a TPC of 1.4–35.1 mg/g for MeOH and 6.3–52.3 mg/g for 50% acetone extracts; they had a TFC of 1.7–25.5 mg/g for MeOH and 3.8–50.3 mg/g for 50% acetone; and they had a TSC of 17.6–193.4 mg/g for MeOH and 24.9–681.2 mg/g for 50% acetone. The RDSC of these samples had a range of 5.7–148.7 μmol/g for MeOH and 33.6–416.8 μmol/g for 50% acetone extracts. The HOSC of these samples had a range of 122.1–1618.3 μmol/g for MeOH and 223.7–4113.0 μmol/g for 50% acetone extracts. In addition, quercetin-di-(rhamno)-hexoside, kaempferol 3-O-di-p-coumaroylhexoside, kaempferol 3-O-di-p-coumaroylhexoside, quercetin-rhamno-hexoside, rutin, kaempferol-rhamno-hexoside, kaempferol-3-O-rutinoside, quercetin and kaempferol were identified in the jiaogulan samples. Principle component analysis (PCA) classified the eleven jiaogulan samples into three groups. These results suggested the possible variation of commercial jiaogulan products in their chemical compositions and health properties, and a need of improved quality control and assurance mechanism.