16-Hydroxycembra-1,3,7,11-tetraene, a new Cembrane Diterpene from Malaysian Soft Coral Genus Sarcophyton

Abstract

One new cembrane diterpene, 16-hydroxycembra-1,3,7,11-tetraene (1), along with three known compounds, 15-hydroxycembra-1,3,7,11-tetraene (2), sarcophine (3) and sarcophytoxide (4) were isolated from Sarcophyton sp. collected from Karah Island, Terengganu, West Malaysia. Their structures were elucidated based on spectroscopic data. Activities of these compounds against antibacterial resistant clinical bacteria are reported. Only 1 exhibited inhibition against Staphylococcus aureus.

A Brief Review on New Naturally Occurring Cembranoid Diterpene Derivatives from the Soft Corals of the Genera Sarcophyton, Sinularia, and Lobophytum Since 2016

“…Different fractions originate the cembranoid compounds, which can be subjected to semi- or preparative HPLC (high performance liquid chromatography). The identification of compounds is generally made through 1 H-NMR (proton nuclear magnetic resonance), 13 C-NMR (Carbon-13 nuclear magnetic resonance), one dimensional and two dimensional nuclear magnetic resonance (1D-NMR and 2D-NMR) including 1 H- 1 H COSY, HMQC, HMBC, and NOESY spectra (Correlation Spectroscopy, Heteronuclear Multiple-Quantum Correlation, Heteronuclear Multiple-Bond Correlation Spectroscopy, Nuclear Overhauser Effect Spectroscopy, respectively), Time-Dependent Density Functional Theory Electronic Circular Dichroism (TDDFT/ECD), Density Functional Theory (DFT)/NMR calculations, FTIR (Fourier-transform infrared spectrosocopy), single crystal X-ray diffraction, and LC-MS-IT-TOF (liquid chromatography–mass spectrometry-ion trap-time-of-flight) [ 9 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ].…”

“…Kamada et al [ 21 ] from a Malaysian specimen of Sarcophyton sp., collected at the Karah Island (West Malaysia), isolated, identified and evaluated the antibacterial activity of 16-hydroxy-cembra-1,3,7,11-tetraene ( 15 ) ( Figure 2 ), a new cembrane, along with the known cembrane diterpenes 15-hydroxycembra-1,3,7,11-tetraene ( 16 ), sarcophine ( 17 ), and sarcophytoxide ( 18 ). The antimicrobial activity of all compounds was assayed against antibiotic resistant clinical bacterial strains Staphylococcus aureus and Escherichia coli .…”

“…Only the new compound presented inhibition against Staphylococcus aureus . Its MBC (Minimum Bactericidal Concentration) and MIC (Minimum Inhibitory Concentration) were 75 and 25 μg/mL, respectively [ 21 ].…”

Chemical Diversity in Species Belonging to Soft Coral Genus Sacrophyton and Its Impact on Biological Activity: A Review

“…From Sarcophyton sp., one cembrane diterpene, 16-hydroxycembra-1,3,7,11-tetraene 257, besides, 15-hydroxycembra-1,3,7,11-tetraene 258 were reported. Structures were investigated by spectral data [85].…”

Bioactive Cembranoids from the Soft Coral Genus Sinularia sp. in Borneo

“…Our previous studies on the chemical constituents from Malaysian soft corals have yielded a variety of interesting metabolites, including sesquiterpenes [ 1 , 2 , 3 , 4 ], norsesquiterpenes [ 5 ], lobane [ 6 ], cembrane diterpenes [ 7 , 8 , 9 , 10 , 11 ], xenicanes [ 12 , 13 ], and sterols [ 4 , 14 ] with potent biological activities such as anti-inflammatory [ 1 ], antibacterial [ 3 , 4 , 6 , 9 , 10 , 13 ], and antifungal actions [ 11 , 12 ], as well as cytotoxicity against adult T-cell leukemia [ 11 , 12 , 13 ] and other cell lines [ 4 , 9 ]. Cembranes are 14-membered ring diterpenes that have frequently been reported as a major chemical constituent in soft corals of the order Alcyonacea [ 15 , 16 , 17 , 18 ].…”