A new indole alkaloid, antioxidant and antibacterial activities of crude extracts from Saccocalyx satureioides

Abstract

The new acylated indole alkaloid glucoside indole-3-carboxylic acid-(6'-O-caffeoyl)-β-D-glucoside 1 has been isolated from the ethyl acetate (EtOAC) extract of Saccocalyx satureioides Coss. & Dur. (Lamiaceae) together with eight known secondary metabolites 2-9. Two indoles 2 and 3, five methylated flavone aglycones 4-8 and one monoterpene glucoside 9 were reported for the first time in the genus Saccocalyx. The structural elucidation of these compounds was accomplished by spectroscopic methods including 1 D (¹H and ¹³C) and 2 D (COSY, HSQC and HMBC) NMR techniques, and mass spectrometry, and by comparison with literature data. Light petroleum, EtOAc, chloroform and n-butanol (n-BuOH) extracts of S. Satureioides were screened for their antioxidant activity using DPPH radical scavenging and β-carotene bleaching methods. The antibacterial activity of these extracts indicates that n-BuOH and EtOAc extracts possess the strongest activity.

Graphical Abstract

Keywords:

• Saccocalyx satureioides
• Lamiaceae
• indole
• antioxidant activity
• antibacterial activity
• NMR

Disclosure statement

No conflict of interest reported by authors.

Additional information

Funding

The authors wish to express thanks to the DGRSDT of the Algerian Minister of Higher Education and Scientific Research for providing a research grant, and to the Department of Chemistry and QOPNA (FCTUID/QUI/00062/2013, Portuguese NMR Network), University of Aveiro, Portugal for providing research facilities and technical support.