Further New Highly Oxidative Cembranoids from the Hainan Soft Coral Sarcophyton trocheliophorum

Three new highly oxidative cembranoids,sarcophytrols D-F(1-3),were obtained from the South China Sea soft coral Sarcophyton trocheliophorum,along with two known related ones(4 and 5).Their structures were elucidated by extensive spectroscopic analyses and by comparison with literature data.The discovery of these new secondary metabolites enriched the family of cembranoids deduced from the title animal.

Cembranoids of Soft Corals:Recent Updates and Their Biological Activities

Soft corals are well-known as excellent sources of marine-derived natural products.Among them,members of the genera Sar-cophyton,Sinularia,and Lobophytum are especially attractive targets for marine natural product research.In this review,we reported the marine-derived natural products called cembranoids isolated from soft corals,including the genera Sarcophyton,Sinularia,and Lobophytum.Here,we reviewed 72 reports published between 2016 and 2020,comprising 360 compounds,of which 260 are new compounds and 100 are previously known compounds with newly recognized activities.The novelty of the organic molecules and their relevant biological activities,delivered by the year of publication,are presented.Among the genera presented in this report,Sarcophyton spp.produce the most cembranoid diterpenes;thus,they are considered as the most important soft corals for marine natural product research.Cembranoids display diverse biological activities,includ-ing anti-cancer,anti-bacterial,and anti-inflammatory.As cembranoids have been credited with a broad range of biological activities,they present a huge potential for the development of various drugs with potential health and ecological benefits.

Xishaglaucumins A—J,New Cembranoids with Anti-Inflammatory Activities from the South China Sea Soft Coral Sarcophyton glaucum

Ten new cembrane-type diterpenoids,namely xishaglaucumins A—J(1—10),along with ten known related ones(11—20),have been isolated from the soft coral Sarcophyton glaucum collected off the Xisha Island in the South China Sea.Their structures were elucidated by extensive spectroscopic analysis,quantum mechanical nuclear magnetic resonance(QM-NMR)methods,X-ray diffraction analysis,chemical methods and comparison with the reported data in the literature.The absolute configuration of new compounds 1,5 and known compounds 11,12,16 and 20 were determined either by chemical methods or by X-ray diffraction analysis using Cu Kα(λ=1.5417A).In in vitro bioassay,compound 4 exhibited inhibitory effects on lipopolysaccharide(LPS)-induced inflammatory responses in BV-2 microglial cells.

Polyoxygenated Cembranoids from Soft Coral Lobophytum Crassum and Their Anti-tumoral Activities

Main observation and conclusion Four new cembranoids,6-oxo-cembrene-A(1),lobocrassins G-H(2-3),and 14-epi-lobophytolide B(4),along with eight known re-lated compounds(5-12),were isolated from the South China Sea soft coral Lobophytum crassum.Their structures were established by extensive spectroscopic analysis and by comparison of the spectral data with those reported in the literatures.The absolute stere-ochemistry of 14-epi-lobophytolide B(4)was established by time-dependent density functional theory electronic circular dichroism(TDDFT-ECD)calculations,whereas that of three known metabolites(6,11 and 12)was also determined,for the first time,by using modified Mosher's method and/or X-ray diffraction analyses.In bioassay,the cembranoids 6,7 and 12 showed significant an-ti-tumoral activity against A549,HT-29,SNU-398 and Capan-1 tumor cell lines with IC_(50) values ranging from 1.5 to 7.4μmol/L.A pre-liminary structure-activity relationship was also discussed.

A study on the sulfenylchlorination of cembrene and the related cembranoids

p-Tolylsulfenyl chloride adds regioselectively at the C(11)=C(12) bond of cembrene 1 to give 11-(R)-p-tolylthio-1-(S)-cembra-2E, 4Z, 7E, 12(20)-tetraene 2 following a rapid HCl elimination. Two new cembranoids, 1-(S)-cembra-2E, 4Z, 7E, 12(20)-tetraene 3 and 1-(S)-cembra-2E, 4Z, 7E, 11Z- tetraen-20-o1 4 are prepared from 2.

Sarcocinerenoids A—J,Eight Rare Capnosane-Type and Two New Cage-Type Cembranoids with Promoting Angiogenesis Activity from the South China Sea Soft Coral Sarcophyton cinereum

Backgroundand Originality Content,Cembranoids are a structurally diverse class of diterpenoids commonly occurring in marine and terrestrial organisms.(+)-Cembrene was the first reported cembranoid diterpenoid discovered in 1962,l and more than 1400 cembranoid diterpenoids have been identified in the last six decades,[2]Cembranoids are characterized by a 14-membered carbocyclic ring,an isopropyl group and three methyl groups,which form their core carbon skeleton.Enzymatic processes such as oxidation,oxidative rearrangements and transannular cyclizations occur in organisms,leading to the formation of distinctive specialized metabolites such as epoxide,lactone,ester,furan,pyrane and other ringbased cembranoids.[2-3]

New Cembrane-Type Diterpenoids from the South China Sea Soft Coral Sinularia nanolobata

In the present study,nine new cembrane-type diterpenoids,namely ximaonanolobatins A—I(1—9),together with six related known analogs(10—15)and four known tetraprenylated alkaloids malonganenones D,E,H,and K(16—19)were isolated from the soft coral Sinularia nanolobata collected off the Ximao Island in the South China Sea.The structures of 1—9 were robustly established by a combination of detailed spectroscopic analyses,chemical reactions,quantum mechanical(QM)-NMR methods,biogenetic consideration,and the comparison with those literature data.The absolute configuration of 1 was confirmed by X-ray diffraction analysis,and the absolute configuration of 2 was determined by QM-NMR calculations and chemical transformation.In addition,the absolute configuration of 3 was determined using the modified Mosher's method.All these isolates were evaluated for their anti-inflammatory and anti-tumor activities.The results showed that only compound 15 exhibited potential anti-inflammatory effect against LPS-induced TNF-αrelease in RAW264.7 macrophages with an IC50 value of 12.6μmol/L.

Cembranoid, Steroid, and Sesquiterpenoid Derivatives from the South China Sea Soft Coral Sinularia numerosa

Two new cembranoids, namely, sinumerolides A and B （1 and 2）, one new steroid, 7fl-hydroxygorgosterol （7）, along with four known cembranoid derivatives （3-6）, four known steroids （8-11）, and four known africane ses- quiterpenoids （12-15）, were isolated and identified from the marine soil coral Sinularia numerosa that was col- lected from South China Sea waters. The structures of these metabolites were elucidated on the basis of extensive spectroscopic analysis and by comparison of their spectral data with those of literature reports. The isolated com- pounds were evaluated for the antimicrobial and cytotoxic activity.