Two new simple iridoids from the ant-plant Myrmecodia tuberosa and their antimicrobial effects

Abstract

Six iridoid derivatives (1–6), including two new compounds myrmecodoides A and B (1 and 2), were isolated from the ant-plant Myrmecodia tuberosa. Their structures were determined on the basis of spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, NOESY and HR-ESI-MS) and by comparison with the literature values. Among isolates, 3 and 4 exhibit weak antibacterial effect against Staphylococcus aureus subsp. aureus with MIC value of 100.0 μg/mL.

Keywords:

• Myrmecodia tuberosa
• Rubiaceae
• ant-plant
• iridoid
• antimicrobial activity

Acknowledgements

The authors are grateful to Dr Tran Thi Nhu Hang, Institute of Natural Products Chemistry, VAST for the antimicrobial evaluation; and the Institute of Chemistry, VAST for measurement of the NMR spectra.

Funding

This work was supported by a Vietnam national project of the Tay Nguyen 3 Program (code: TN3/T14) and the Priority Research Center Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology [grant number 2009–0093815], Republic of Korea.

Disclosure statement

No potential conflict of interest was reported by the authors.