Antibiotic Guanacastane Diterpenoids with Two New Skeletons from Uncovered by Semisolid and Liquid Media.

The culture of in host medium produced seven new guanacastane diterpenoids, psayamin () as an unprecedented 5/7/6/6/6/6/7/5-fused octacyclic spiro scaffold both under liquid and semisolid conditions, psathins A-C () with a 5/7/6 tricyclic backbone by liquid medium, psathins D-E () as the same unprecedented skeletons of 5/6/7/6-fused tetracyclic or 6/7/6 tricyclic structures, and psathin F () with a 5/7/5/6 tetracyclic backbone by semisolid medium. The structures were elucidated by detailed spectroscopic analyses and those of and were determined by single-crystal X-ray crystallography. The semisolid culture led to four structure types of the guanacastane diterpenoid. Compound showed antifungal activity against phytopathogen with a minimum inhibitory concentration (MIC) of 8 μg/mL, while compound showed significant antifungal activity against sp. with an MIC of 2 μg/mL. Compounds and also showed antifeedant activities against the silkworms with the feeding deterrence indices of 50%, at the concentrations of 50 μg/cm. Compound showed significant cytotoxicity with IC at 10.87 ± 0.24-15.96 ± 0.30 μM and anti-acetylcholinesterase activity with IC at 37.3 μM. Also, compound remarkably induced apoptosis of HL-60 at 10, 20 μM in a concentration-dependent manner. The spiral ring of was vital in cytotoxicity and anti-acetylcholinesterase activity. The different media fermented by resulted in the chemical diversity of bioactive guanacastane diterpenoids and potential applications in the agricultural and food functions.