New Antibacterial Diterpenoids from the South China Sea Soft Coral Klyxum molle

Abstract

Fifteen new diterpenoids, namely xishaklyanes A-O (1–15), along with three known related ones (16–18), were isolated from the soft coral Klyxum molle collected from Xisha Islands, South China Sea. The stereochemistry of the new compounds was elucidated by a combination of detailed spectroscopic analyses, chemical derivatization, quantum chemical calculations, and comparison with the reported data. The absolute configuration of compound 18 was established by the modified Mosher’s method for the first time. In bioassay, some of these compounds exhibited considerable antibacterial activities on fish pathogenic bacteria, and compound 4 showed the most effective activity with MIC of 0.225 μg/mL against Lactococcus garvieae.

In Vitro Insights into the Role of 7,8-Epoxy-11-Sinulariolide Acetate Isolated from Soft Coral Sinularia siaesensis in the Potential Attenuation of Inflammation and Osteoclastogenesis

“…Marine natural products are universally acknowledged as the metabolites characterized by unique chemical structure and diverse biological activities and attract increasing attention in the study of degenerative inflammatory diseases [14,15]. In the course of our ongoing program toward the search for novel and bioactive metabolites from marine organisms, we have reported a series of new sesterterpenes, diterpenoids, alkaloids, and so on [16,17]. The compound 7,8-epoxy-11-sinulariolide acetate (Esa) is a diterpenoid isolated from the soft coral sinularia siaesensis by our group, and it was first isolated from the formosan soft coral Sinularia flexibilis by Hsieh in 2003 [18].…”