Myrtucommulones F-I, phloroglucinols with thyrotropin-releasing hormone receptor-2 binding affinity from the seeds of Corymbia scabrida.
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 microM, respectively.
Carroll
Anthony R
AR
Eskitis Institute, Griffith University, Brisbane, Queensland, Australia 4111.
Lamb
Jasmine
J
Moni
Roger
R
Guymer
Gordon P
GP
Forster
Paul I
PI
Quinn
Ronald J
RJ
D000818:Animals; D015394:Molecular Structure; D027822:Myrtaceae / Q000737:chemistry*; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D011793:Queensland; D051381:Rats; D018025:Receptors, Thyrotropin-Releasing Hormone / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry
D018025:Receptors, Thyrotropin-Releasing Hormone; C455139:myrtucommulone A; D010696:Phloroglucinol