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Molecular networking strategy-based prioritization of the isolation of the rarely studied soft coral Sinularia tumulosa yielded 14 sesquiterpenes. These isolated constituents consisted of nine different types of carbon frameworks, namely asteriscane, humulane, capillosane, seco-asteriscane, guaiane, dumortane, cadinane, farnesane, and benzofarnesane. Among them, situmulosaols A-C (1, 3 and 4) were previously undescribed ones, whose structures with absolute configurations were established by the combination of extensive spectral data analyses, quantum mechanical-nuclear magnetic resonance and time-dependent density functional theory electronic circular dichroism calculations, the Snatzke's method, and the modified Mosher's method. Notably, situmulosaol C (4) was the second member of capillosane-type sesquiterpenes. The plausible biogenetic relationships of these skeletally different sesquiterpenes were proposed. All sesquiterpenoids were evaluated for their antibacterial, cytotoxic and anti-inflammatory effects. The bioassay results showed compound 14 exhibited significant antibacterial activities against a variety of fish and human pathogenic bacteria with MIC 90 values ranging from 3.6 to 33.8 μg/mL. Moreover, moderate cytotoxic effects against HEL cells for components 13 and 14 and moderate inhibitory effect on lipopolysaccharide-induced inflammatory responses in RAW264.7 cells for substance 13 were also observed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The chemical investigation on the soft coral Sinularia brassica collected off Xuwen Country, Guangdong Province, China, has resulted in the isolation and characterization of three uncommon cycloamphilectane-type diterpenoids, namely sinucycloamtin A-C (1-3), along with two known analogues (5 and 6). In addition, compounds 2 and 3 were hydrolyzed and their hydrolytic derivative sinucycloamtin D (4) was obtained. The structures of these previously undescribed compounds were established on the basis of extensive spectroscopic analysis, X-ray diffraction analysis, chemical conversion, as well as the comparison with the literature reported data. Compounds 1-3 represented the first examples of benzene-containing cycloamphilectane-type diterpenoids isolated from soft coral of genus Sinularia. In the in vitro bioassays, all the isolated and derived diterpenoids exhibited significant antibacterial activities against the fish pathogenic bacteria Phoyobacterium damselae FP2244 and Streptococcus parauberis SPOF3K with MIC 90 values ranging from 3.7 to 9.1 μM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Five new cembrane-type diterpenes, lobocalines A-E ( 1 - 5 ), and four new steroids, lobocaloids A-D ( 9 - 12 ), along with six known related compounds ( 6 - 8 and 13 - 15 ) were isolated from the Yalong Bay soft coral Lobophytum catalai Tixier-Durivault. The structures of the new compounds were elucidated by extensive spectroscopic analysis, NMR calculation with DP4+ analysis, time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD) calculations, X-ray diffraction analyses and comparison with the reported spectroscopic data of known compounds. Further, with the aid of X-ray diffraction analysis, the structure of lobocrasol B ( 15 ) was firmly revised as 15a . In in vitro bioassays, compound 2 showed moderate antibacterial activities against fish pathogenic bacteria Streptococcus parauberis KSP28 and Phoyobacterium damselae FP2244 with minimum inhibitory concentration (MIC) values of 8.7 and 17.3 µg/mL, respectively. All the steroids exhibited antibacterial activities against the S. parauberis KSP28 with MIC values ranging from 12.3 to 53.6 µg/mL. Compounds 2 , 7 and 14 have remarkable inhibitory effects on the hemolysin production of Staphylococcus aureus , while compounds 8 - 12 have medium inhibitory effects on the pyocyanin production in Pseudomonas aeruginosa .

The detailed chemical investigations of the South China Sea soft corals Sinularia tumulosa and Sinularia depressa , yielded two new compounds, namely tumulosterol A ( 1 ) and 11'-hydroxy- α -tocopherylquinone ( 3 ), along with four related known ones ( 2 , 5 - 7 ). Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data previously reported in the literature. In bioassays, compound 1 displayed significant cytotoxic effects against H1975 and MDA-MB-231 cells with IC 50 values of 6.0 and 6.3 µM, respectively. In addition, compound 3 exhibited interesting inhibitory effect on lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 cells with IC 50 value of 9.5 µM.

Three new cembranoids ( 1 - 3 ) and a new casbanoid ( 4 ), along with three known analogues ( 5 - 7 ), have been isolated from the soft coral Sinularia nanolobata collected off Ximao Island. The structures, including the absolute configurations of new compounds, were established using extensive spectroscopic data analysis, time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations, and the comparison with spectroscopic data of known compounds. In the in vitro bioassay, compounds 1 and 5 exhibited moderate cytotoxic activities against human erythroleukemia (HEL) cell lines, with IC 50 values of 37.1 and 42.4 μM, respectively.

Three new steroids, along with two known related analogs, were isolated from the Xisha Island soft coral Lobophytum sarcophytoides. The structures and absolute configurations of the new compounds were elucidated by extensive spectroscopic data analyses, time dependent density functional theory electronic circular dichroism calculation, and comparison with the spectral data previously reported in the literature. In in vitro bioassay, four compounds showed interesting suppressive effects on lipopolysaccharide (LPS) induced inflammation in BV-2 microglial cells at 10 μM level., (© 2023 Wiley-VHCA AG, Zurich, Switzerland.)

Nanolobatone A, featuring an unprecedented tricyclo[10.3.0.0 1,2 ]pentadecane carbon skeleton, along with four new polyoxygenated and four unusual endoperoxide-bridged casbane-type diterpenoids were isolated from the Hainan soft coral Sinularia nanolobata. The structures of the new compounds were established by extensive spectroscopic analysis, X-ray diffraction analysis, and time-dependent density functional theory/electronic circular dichroism calculations. A plausible biosynthetic pathway of new isolates was proposed. Bioassays revealed that nanolobatone A showed weak antibacterial activity against the Gram-positive bacteria Streptococcus pyogenes., (© 2023 Wiley-VCH GmbH.)

Four new steroids, namely sinulasterols D-G (1-4), along with seven known related ones 5-11, were isolated from the Xisha soft coral Sinularia depressa. The structures of the new compounds were elucidated by a combination of extensive spectroscopic analyses, chemical conversion method, and comparison of the NMR data with those of known analogues. In in vitro bioassays, compounds 1-3 showed significant antibacterial activities against gram-positive bacteria Enterococcus faecium with minimum inhibitory concentration (MIC) values of 62.5, 125, and 125 µM, respectively, comparable with that of vancomycin (MIC: >44.2 µM)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Documents on the chemical composition of the soft coral Sarcophyton mililatensis are sparse. The present investigation of the Hainan soft coral S. mililatensis resulted in the discovery of six new cembrane diterpenes, sarcoxacyclols A-F ( 1 - 6 ) and four known analogs ( 7 - 10 ). Their structures were elucidated by extensive spectroscopic analysis along with a comparison with the data in current literature. The nonaromatic oxacycles in their structures were the rarely found tetrahydrofuran ether across C-1 and C-12 and tetrahydropyran ether across C-1 and C-11, respectively. Moreover, the absolute configuration of compound 4 was established unambiguously by X-ray diffraction analysis using Ga Kα radiation ( λ = 1.34139 Å). Based on the biogenetical consideration, the absolute configurations of other five new compounds were tentatively assumed. Assessment of the bioactivity for these secondary metabolites revealed that compound 1 exhibited significant tumor necrosis factor (TNF)- α inhibitory activity (IC 50 = 9.5 μmol/L), similar to the positive control dexamethasone (IC 50 = 8.7 μmol/L), but no obvious cytotoxicity towards RAW264.7 cells (CC 50 > 50 μmol/L). The preliminary molecular docking suggested the crucial roles of the hydroxyl and acetoxyl groups in the computational prediction of the binding mode between the diterpene and the protein.

Four new polyoxygenated cembranoids, namely sarcoboettgerol A (1), 12-epi-humilisin D (2), sarcoboettgerol B (3), and sarcoboettgerol C (4), together with one known related analogue, humilisin D (5), were isolated and characterized from the soft coral Sarcophyton boettgeri collected off Ximao island, Hainan Province, China. The structures and absolute configurations of the new compounds were determined by extensive spectroscopic data analyses, Cu kα single crystal X-ray diffraction analysis, and TDDFT-ECD calculations. A plausible biogenetic relationship of 3 and 4 was proposed., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Three unusual diterpenes with rare sarsolenane and capnosane skeletons, namely mililatensols A-C ( 1 - 3 ), were isolated from the South China Sea soft coral Sarcophyton mililatensis , leading to the first record of sarsolenane and capnosane diterpenes from the title animal. The structures of compounds 1 - 3 were established by extensive spectroscopic analysis and comparison with the literature data. Moreover, the absolute configuration of 2 was determined by TDDFT ECD calculations. In an in vitro bioassay, none of the isolated compounds showed obvious anti-inflammatory activity on LPS-induced TNF- α release in RAW264.7 macrophages. In the preliminary virtual screening of inhibitory potential against SARS-CoV-2 by molecular docking, the results showed these three diterpenes were potential SARS-CoV-2 M pro inhibitors., Competing Interests: The authors declare no conflict of interest.

Litosetoenins A-E ( 1 - 5 ), five new ring-rearranged serrulatane-type diterpenoids with a common tricyclo[3.0.4]decane core, along with a known diterpenoid glycoside ( 6 ), a related known diterpenoid ( 7 ), and four known sesquiterpenoids ( 8 - 11 ), were isolated from a Balinese soft coral Litophyton setoensis . Spirolitosetoenin A ( 5a ) and isospirolitosetoenin A ( 5b ), featuring an unprecedented spiro[4,5]decane core, were obtained after treatment of compound 5 with HCl in methanol. The structures of new compounds were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance approach, and chemical methods. A plausible biosynthetic pathway involving an unusual divergent biogenesis was proposed.

Seven new cembrane-type diterpenes, lobophytolins C-I (3-9), and one new prenylated-guiane-type diterpene, lobophytolin J (10), along with six known related ones (1, 2, 11-14), have been isolated from the soft coral Lobophytum sp. collected off the Xisha Island in the South China Sea. Their structures were elucidated by extensive spectroscopic analysis and quantum mechanical (QM)-NMR methods. The absolute configuration of lobophytolin H (8) was determined by the application of the modified Mosher's method and chemical transformation. Lobophytolin D (4) exhibited promising cytotoxicities in in vitro bioassays against HT-29, Capan-1, A549, and SNU-398 human cancer cell lines with IC 50 values of 4.52, 6.62, 5.17, and 6.15 μM, respectively., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Three new oxygenated steroids, sinulasterols A-C (1-3), along with seven known related steroids 4-10, were isolated from the Chinese soft coral Sinularia depressa. The structures of the new compounds were established from extensive spectroscopic data analyses and by comparison of their spectral data with those reported in the literature. Among the new compounds, metabolites 1 and 2 featured on unusual C-18 oxygenated pattern. In the TNF-α bioassay, compound 4 exhibited a potent inhibitory activity (IC 50  = 12.1 μM), which was analogous to the positive control dexamethasone (IC 50  = 8.7 μM), metabolites 1 and 2 displayed a moderate inhibitory activity (IC 50 51.1 μM and 22.7 μM respectively)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Two new hydroperoxy steroids, namely, xidaosteroids A and B (1 and 2), along with five known related compounds 3-7, were isolated from the South China Sea gorgonian Rumphella sp.. Their structures were established by extensive spectroscopic analyses and comparison of the spectral data with those reported in the literature. In bioassay, compound 3 showed weak cytotoxicities against SNU-398 and Capan-1 cells., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Three new nardosinane-type sesquiterpenoids linardosinenes A-C (1-3) and four new neolemnane-type sesquiterpenoids lineolemnenes A-D (4-7), together with the related known compound 4-acetoxy-2,8-neolemnadien-5-one (8), were isolated from the Xisha soft coral Litophyton nigrum. The structures of these new compounds were elucidated by comprehensive analyses of spectroscopic data, in association withmodified Mosher's method and ECD calculations for configurational assignments and the absolute configuration of8was determined by X-ray diffraction analysis for the first time. Structurally uncommon nornardosinane and seconeolemnane skeletons for compounds 1 and 7, respectively, are rare carbon frameworks in naturally occurring sesquiterpenoids. The absolute configurations of 1, 7, and 8 were determined by modified Mosher's method, TDDFT ECD approach, and X-ray diffraction analysis, respectively. This is the first chemical study of L. nigrum and the first report of nornardosinane, seconeolemnane and related sesquiterpenoids from the genus Litophyton. The isolates 1-7 were evaluated for their cytotoxicity against THP-1, SNU-398, HT-29, Capan-1 and A549 cell lines and inhibitory activities against PTP1B, BRD4, HDAC1 and HDAC6 protein kinases. The results indicated that compounds 2-5 inhibited proliferation of human cancer cells. However, none of them were potent inhibitors of protein kinases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

One new polycyclic furanobutenolide-derived norcembranoid, xiguscabrolide H (1), together with eleven known related norditerpenoids 2-12 were isolated from South China Sea soft corals Sinularia scabra and S. polydactyla, respectively. Among them, compounds 1, 6, 8, and 12 were discovered from the former species, while compounds 2-5, 7, and 9-11 were obtained from the latter species. The structure of new compound 1 was elucidated by extensive spectroscopic analysis and by the comparison with the reported data. With the assistance of time-dependent density functional theory electronic circular dichroism (TDDFT-ECD) calculations, its absolute configuration was determined. Moreover, the absolute stereostructures of the known compounds 3, 4, and 9-12, of which only relative configurations were assigned, were established for the first time by X-Ray diffraction analysis and TDDFT-ECD calculations, respectively. In bioassay, several isolates exhibited potent inhibitory effects on the ConA-induced T lymphocytes and/or LPS-induced B lymphocytes proliferation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Two new steroids, ximaosteroid E (1) and ximaosteroid F (2), along with two known related compounds (3 and 4), were isolated from the Chinese soft coral Sinularia sp. Notably, 1 possesses an uncommon dihydrofuran group. Their structures were established from extensive spectroscopic analyses and comparisons of their spectral data with those reported in the literature. The absolute configuration of 2 was determined by applying the modified Mosher's method. In bioassay, compounds 1, 2, and 4 showed significant cytotoxicity against the HL-60 tumor cell line with IC 50 values of 1.79, 4.03 and 0.69 μM, respectively., (Copyright © 2018 Elsevier Inc. All rights reserved.)