Six new iridoid glycosides from the whole plants of Hedyotis diffusa

Abstract

Six new iridoid glycosides were isolated from the ethyl acetate fraction of the whole plants of Hedyotis diffusa Willd. They were identified as E-6-O-p-methoxycinnamoyl-10-O-acetyl scandoside acid methyl ester (1), Z-6-O-p-methoxycinnamoyl-10-O-acetyl scandoside acid methyl ester (2), E-6-O-caffeoyl scandoside methyl ester (3), E-6-O-p-coumaroyl-6′-O-acetyl scandoside methyl ester (4), Z-6-O-p-coumaroyl-6′-O-acetyl scandoside methyl ester (5), and E-6-O-p-coumaroyl-4′-O-acetyl scandoside methyl ester (6). The structures of them were elucidated based on unambiguous spectroscopic data (UV, IR, HRESIMS, and NMR). They were screened for anti-inflammatory effect, antioxidant effect, antitumor effect, and neuroprotective effect and did not show potent activities.

Keywords:

• Rubiaceae
• Hedyotis diffusa
• iridoid glycosides
• scandoside

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

1D and 2D NMR, UV, IR, and HR-ESI-MS data of compounds 1–6 were provided in the supplementary material.

Additional information

Funding

This work was supported financially by the Chinese Academy of Medica Sciences (CAMS) Innovation Fund for Medical Sciences [No. 2022-I2M-JB-009].