Novel Sesquiterpene and Diterpene Aminoglycosides from the Deep-Sea-Sediment Fungus <i>Trichoderma</i> sp. SCSIOW21

Abstract

Six new sesquiterpene aminoglycosides, trichaspside F (2) and cyclonerosides A–E (5–9), two new diterpene aminoglycosides, harzianosides A and B (10, 11), and three known sesquiterpenes, trichodermoside (1), cycloneran-3,7,10,11-tetraol (3), and cyclonerodiol (4), have been isolated from the n-butanol extract of Trichoderma sp. SCSIOW21 (Hypocreaceae), a deep-sea-sediment-derived fungus. The structures and relative configurations of the new compounds were determined using spectroscopic techniques and comparisons with those reported in the literature. The absolute configurations of the aglycone part of cyclonerosides A–E (5–9) were tentatively proposed based on optical rotation and biogenic considerations. Cyclonerosides A–E (5–9) represent the first glycosides of cyclonelane-type sesquiterpenes generated from Trichoderma. The NO-production-inhibitory activities were evaluated using macrophage RAW264.7 cells. Among the isolated compounds, trichaspside F (2) and cyclonerosides B–E (6–9) exhibited the strongest NO-production-inhibitory activities with IC50 values of 54.8, 50.7, 57.1, 42.0, and 48.0 µM, respectively, compared to the IC50 value of 30.8 µM for the positive control (quercetin). When tested for anti-fungal activities against several pathogenic fungi, none of the compounds exhibited significant activities at a concentration of 100 µM.

Keywords

• Sesquiterpene aminoglycoside
• diterpene aminoglycoside
• <i>Trichoderma</i> sp.
• deep sea fungus
• NO-production-inhibitory activity
• anti-fungal activity