New cyclomyrsinol diterpenes from Euphorbia aellenii with their immunomodulatory effects

Abstract

Chloroform–acetone extract of the aerial parts of Euphorbia aellenii Rech. f. (Euphorbiaceae) was investigated for its diterpenoidal constituents. This led to the isolation of two new and one known cyclomyrsinol-type diterpenes 1–3. The structures were elucidated on the basis of 1D and 2D ¹H and ¹³C NMR techniques, and in vitro immunomodulatory activity was evaluated by standard proliferation of human peripheral blood lymphocytes. Results showed that all the three compounds were found to inhibit lymphocyte proliferation significantly (p < 0.05) at 50 μg/ml concentration. Among them, compound 2 showed more activity against phytohemagglutinin-activated T-cell proliferation with an IC₅₀ of 40.4 ± 9.35 μg/ml.

Keywords:

• Euphorbiaceae
• Euphorbia aellenii
• cyclomyrsinol
• immunomodulation

Acknowledgment

M. Ghanadian thanks the H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, for generous financial supports.