In the present study, a new polyoxygenated cembranoid named sarcomililatol H (1) as well as six known terpenes 2-7 with different skeletons were isolated from South China Sea soft coral Sarcophyton mililatensis. Based on the comprehensive analyses of 1D and 2D NMR spectroscopic data, the structure of the new compound 1 was established. This new cembranoid was characterized by the presence of the rarely encountered tetrahydropyran ring with the ether linkage across C-2 and C-12. By applying the time-dependent density functional theory electronic circular dichroism (TDDFT ECD) approach, the absolute configuration of sarcomililatol H (1) was determined. All of the isolates were subjected to the anti-inflammatory and anti-tumor bioassays. However, none of them was active in these evaluations. Additionally, the preliminary virtual screening of inhibitory against SARS-CoV-2 by molecular docking showed that diterpene 1 could be regarded as a SARS-CoV-2 main protease (Mpro ) inhibitor (binding energy: -7.63 kcal/mol). The discovery of these terpenes has expanded the chemical diversity and complexity of terpenes from the species S. mililatensis.
Keywords: SARS-CoV-2 Mpro inhibitor; Sarcophyton mililatensis; soft coral; structural elucidation; terpene.
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