Three new dihydroflavonols with free radical scavenging activity from Ribes himalense Royle ex Decne

Abstract

Ribes himalense Royle ex Decne, a small shrub, is widely used as a Tibetan medicine in Chinese folk. In this study, three novel 1,1-diphenyl-2-picrylhydrazyl inhibitors named Rihimaside A, Rihimaside B, and Rihimaside C, as well as one known 1,1-diphenyl-2-picrylhydrazyl inhibitor, dihydromyricetin, were isolated from the leaves and stems of Ribes himalense Royle ex Decne using online high performance liquid chromatography-1,1-diphenyl-2-picrylhydrazyl activity screening system combined with medium and high-pressure liquid chromatography. All four 1,1-diphenyl-2-picrylhydrazyl inhibitors are dihydroflavonols. The 1,1-diphenyl-2-picrylhydrazyl scavenging activity and IC₅₀ values of three novel 1,1-diphenyl-2-picrylhydrazyl inhibitors were determined using 1,1-diphenyl-2-picrylhydrazyl methods. Rihimaside A, Rihimaside B, and Rihimaside C exhibited IC₅₀ values of 9.58 μg/mL, 12.57 μg/mL and 387 μg/mL, respectively.

Graphical Abstract

Keywords:

• Ribes himalense
• dihydroflavonols
• liquid chromatography
• structure identification
• 1,1-diphenyl-2-picrylhydrazyl scavenging activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Natural Science Foundation of Qinghai Province (2018-ZJ-913), the support of the International Cooperation Project of Qinghai Province (2019-HZ-805), the Joint Research Project of Three-River Headwaters National Park, Chinese Academy of Sciences and The People's Government of Qinghai Province (LHZX-2020-09), Qinghai Key Laboratory of Tibetan Medicine Research (2021-ZJ-Y03), the Applied Basic Research Project of Qinghai Province (2020-ZJ-706).