Myrtucommulones F−I, phloroglucinols with thyrotropin-releasing hormone receptor-2 binding affinity from the seeds of Corymbia scabrida
Carroll, A. R., Lamb, J., Moni, R., Guymer, G. P., Forster, P. I., & Quinn, R. J. (2008). Myrtucommulones F−I, phloroglucinols with thyrotropin-releasing hormone receptor-2 binding affinity from the seeds of Corymbia scabrida. Journal of Natural Products, 71(9), 1564–1568. doi:10.1021/np800247u
High-throughput screening of a plant and marine invertebrate extract library to find natural products with rat thyrotropin-releasing hormone (TRH) receptor-2 binding affinity led to the isolation of four new, myrtucommulones F−I (3−6), and two known, myrtucommulones A (1) and D (2), active acylphloroglucinols from the seeds of the Queensland tree Corymbia scabrida. Their structures were assigned from interpretation of 2D NMR and high-resolution ESIMS data. The relative configuration of the stereogenic centers for all six compounds was deduced from ROESY correlations. This is the first time that myrtucommulone A (1) has been isolated as a single pure compound. The structure of myrtucommulone D (2) has been revised. Myrtucommulones A, D, and F−I showed rat TRH receptor-2 binding affinity with IC50 values of 39, 11, 16, 24, 31, and 16 μM, respectively.