Two novel polyketones from the leaves and twigs of Clerodendrum trichotomum

Abstract

Two novel polyketones, along with four known compounds, were isolated from the leaves and twigs of Clerodendrum trichotomum. Their structures were determined to be clerodendruketone A (1), clerodendruketone B (2), ecdysanols E (3), ecdysanols D (4), 5,5′-dimethoxy-7-oxolariciresinol (5), and (-)-(7′S,8S,8′R)-4,4′-dihydroxy-3,3′,5,5′-tetramethoxy-7′,9-epoxy-lignan-9′-ol-7-one (6) through the methods of NMR, HRESIMS and ECD data analyses. The antioxidant effects against free radical were tested by DPPH assay. The antibacterial activity against Escherichia coli and Staphylococcus aureus were tested by turbidimetry assay. The results demonstrated that compounds 1 and 2 had significative antibacterial activity, and compound 3 had moderate antioxidant activity.

Graphical Abstract

Keywords:

• Lamiaceae
• Clerodendrum trichotomum
• polyketones
• DPPH scavenging
• antioxidant activity
• antibacterial activity

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research was funded by the National Key R&D Program of China (2017YFC1701200), the National Natural Science Foundation of China (81903789) and the China Postdoctoral Science Foundation (2020M670675).