Novel Harziane Diterpenes from Deep-Sea Sediment Fungus Trichoderma sp. SCSIOW21 and Their Potential Anti-Inflammatory Effects

Abstract

Five undescribed harziane-type diterpene derivatives, namely harzianol K (<b>1</b>), harzianol L (<b>4</b>), harzianol M (<b>5</b>), harzianol N (<b>6</b>), harzianol O (<b>7</b>), along with two known compounds, hazianol J (<b>2</b>) and harzianol A (<b>3</b>) were isolated from the deep-sea sediment-derived fungus <i>Trichoderma</i> sp. SCSIOW21. The relative configurations were determined by meticulous spectroscopic methods including 1D, 2D NMR spectroscopy, and HR-ESI-MS. The absolute configurations were established by the ECD curve calculations and the X-ray crystallographic analysis. These compounds (<b>1</b>, and <b>4</b>-<b>7</b>) contributed to increasing the diversity of the caged harziane type diterpenes with highly congested skeleton characteristics. Harzianol J (<b>2</b>) exhibited a weak anti-inflammatory effect with 81.8% NO inhibition at 100 µM.