Leptosperols A and B, Two Cinnamoylphloroglucinol–Sesquiterpenoid Hybrids from <i>Leptospermum scoparium</i>: Structural Elucidation and Biomimetic Synthesis

Abstract

Leptosperols A and B (<b>1</b> and <b>2</b>), two cinnamoylphloroglucinol-sesquiterpenoid hybrids featuring unprecedented 1-benzyl-2-(2-phenylethyl) cyclodecane and 2-benzyl-3-phenylethyl decahydronaphthalene backbones, along with their biosynthetic precursor (<b>3</b>), were isolated from <i>Leptospermum scoparium</i>. Compounds <b>1</b> and <b>2</b> represent the first example of phloroglucinol derivatives biogenetically constructed by a De Mayo reaction. The biomimetic synthesis of leptosperol B (<b>2</b>) was achieved using the proposed biosynthetic pathway. In addition, compounds <b>1</b> and <b>2</b> showed significant anti-inflammatory effects in zebrafish acute inflammatory models.