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A further study on the rarely reported soft coral Sarcophyton mililatensis disclosed five new flexible cembrane-type macrocyclic diterpenes sarcomililatols C-G (1-5) and two known analogues 6 and 7. The structures and absolute configurations of natural macrocyclic compounds 1-6 were established by the extensive spectroscopic analysis, X-ray diffraction analysis, time-dependent density functional theory/electronic circular dichroism (TDDFT ECD) calculations, chemical reaction, and modified Mosher's method. In the bioassays, the macrocyclic diterpene 2 exhibited potent TNF-α inhibition (IC

Marine octocorals belonging to the genus Cladiella, usually encountered on reefs in the Indo-Pacific region, have been proven to be rich sources of diverse secondary metabolites with intriguing structural features and promising bioactivities. In this review, 155 compounds from six unambiguously identified C. krempfi, C. australis, C. pachyclados, C. hirsuta, C. tuberculosa, C. conifera, together with several unidentified Cladiella spp. are summarized covering the literatures from 2006 to August 2022. It is noteworthy that diterpenoids dominated the secondary metabolite profile of this genus counting for 78 %. Structurally, the majority of these diterpenes belonged to eunicellan family characterized by different patterns of ether linkage. The impacts of these chemical compositions on an array of potential pharmacological activities were also reviewed, giving an overview of the potential application of Cladiella secondary metabolites.

Five analogs of dimethylallyl diphosphate (DMAPP) with additional or shifted Me groups were converted with isopentenyl diphosphate (IPP) and the fungal variediene synthase from Aspergillus brasiliensis (AbVS). These enzymatic reactions resulted in the formation of several new terpene analogs that were isolated and structurally characterised by NMR spectroscopy. Several DMAPP analogs showed a changed reactivity giving access to compounds with unusual skeletons. Their formation is mechanistically rationalised and the absolute configurations of all obtained compounds were determined through a stereoselective deuteration strategy, revealing absolute configurations that are analogous to that of the natural enzyme product variediene.

In this review, we summarized the distribution of the chemically investigated

A detailed chemical research of soft coral Sarcophyton ehrenbergi from the South China Sea yielded five new cembranoids 1-5 featuring an α,β-unsaturated-γ-lactone moiety rarely at C-6 to C-19, along with one known related diterpene 6. The structures and absolute configurations of 1-5 were established in the light of extensive spectroscopic data analysis, chemical reaction, X-ray diffraction analysis, TDDFT/ECD (time-dependent density functional theory/electronic circular dichroism) calculations, and biosynthesis path. This study led to the stereostructural revision of 6, which was misassigned by erroneously applying the empirical ECD helicity rule, indicating a challenging and risky work to determine the structure of this type of marine cembranoids. In the TNF-α inhibitory biotest, compound 2 exhibited a potent inhibitory activity (IC50 = 8.5 μM), which was analogous to the positive control dexamethasone (IC50 = 8.7 μM).

A detailed chemical investigation of the Chinese soft coral Lemnalia flava yielded four new nardosinane-type sesquiterpenoids (1–4), one new neolemnane-type sesquiterpenoid (5), and one new sesquiterpenoid with an uncommon 6/9 fused bicyclic skeleton (6), together with two known related compounds (7 and 8). The structures and absolute configurations of 1–8 were determined on the basis of extensive spectroscopic data analyses, X-ray diffraction analysis, chemical reactions, and computer-assisted structural elucidation including 13C NMR data calculation, residual dipolar coupling based NMR analysis, and time-dependent density functional theoryelectronic circular dichroism calculation. Plausible biogenetic pathways of two uncommon sesquiterpenoids (4 and 6) were proposed.

A new 5α,8α-epidioxysterol, namely yalongsterol A (1), along with two known related steroids 5α,8α-epidioxy-24-methyl-cholesta-6,24(28)-dien-3β-ol (2) and (22E,24S)-5α,8α-epidioxy-24-methyl-cholesta-6,22-dien-3β-ol (3), were isolated from the South China Sea soft coral Sinularia sp. Their structures were established by extensive spectroscopic analyses and comparisons of the spectral data with those reported in the literature. In bioassay, compounds 1-3 showed moderate immunosuppressive activities against T and/or B lymphocyte cells with IC50 values ranging from 19.30 to 59.49 μM, and low cytotoxicity on murine splenocytes with CC50 values ranging from 40.88 to 62.29 μM.[Formula: see text].

A new brominated polyacetylene xestonariene J (1), bearing a rare 2,4-dibromo-1-ene-3-yne terminal in the molecule, along with two known related analogues (2 and 3), was obtained from Chinese marine sponge Xestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and comparison with literature data.

Eleven new cembrane diterpenes, namely, sarcoehrenins A-J (1-9, 11) and (2S,11S,12S)-isosarcophytoxide (10), along with six known compounds, gibberosene B (12), (13S)-cembra-1,3,7,11-tetraen-13-ol (13), (+)-sarcophtol (14), cembrene-C (15), (1R,4R,2E,7E,11E)-cembra-2,7,11-trien-4-ol (16) and (1S,4R,2E,7E,11E)-cembratrien-4-ol (17) were isolated from the soft coral Sarcophyton ehrenbergi collected from Weizhou Island, Beibu Gulf, South China Sea. The structures of these compounds were elucidated by a combination of detailed spectroscopic analyses, chemical methods, and comparison with reported data. The absolute configuration of compound 2 was established by the modified Mosher's method in association with TDDFT ECD calculation, while the absolute configuration of compound 3 was assigned by TDDFT ECD approach. In in vitro bioassays, compounds 13 and 17 showed potent TNF-α inhibitory activities being similar to that of positive control dexamethasone. A preliminary structural-activity relationship was also described.

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.

3-Nor-spongiolide A (1), belonging to the extremely rare 3-nor-spongian carbon skeleton, and spongiolides A (2) and B (3), having γ-butenolide instead of furan ring as usual for ring D, together with six related known metabolites were isolated from South China Sea sponge Spongia officinalis as its metabolic components. Their structures were elucidated on the basis of extensive spectroscopic analysis. The absolute configurations of three new compounds 1–3 were determined by ECD calculations.

A series of highly oxidative new cembranoids with diverse structural features such as a dienoate moiety (sarcophytonolides S – U, 1–3) or an α,β-unsaturated e-lactone (sartrolides H – J, 4–6) were obtained from Hainan soft coral Sarcophyton trocheliophorum, along with known related analogues 7–13. It is an extremely challenging work to determine the absolute configurations of these metabolites. For compounds 1, 3 and 4, solution TDDFT calculation of ECD and specific rotation were applied in combination with conformational analysis and NMR data to determine their relative and absolute configurations, leading to the revision of relative configuration of 14. The absolute configurations of compounds 8–10 were determined by the solid-state TDDFT-ECD approach, and that of 8 was further confirmed by single-crystal X-ray diffraction experiment with Cu Kα radiation. In the bioassays, compound 8 exhibited not only moderate protein tyrosine phosphatase 1B (PTP1B) inhibitory activity (IC50 = 15.4 μM) but also moderate antibacterial activity against Staphylococcus aureus Newman strain (MIC50 = 250 μM).

A novel sarsolenane diterpene, named secodihydrosarsolenone (1), as a minor component was obtained from the South China Sea soft coral Sarcophyton trocheliophorum Marenzeller. Its structure was elucidated by detailed spectroscopic analysis. Compound 1 exhibited moderate inhibitory activity (IC50=13.7 µmol•L−1) against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type 2 diabetes, representing the first report of PTP1B inhibitory activity for sarsolenane diterpenes. This discovery promotes computational prediction of binding mode between the enzyme and the metabolite, suggesting a crucial role of the residues Tyr46, Ser216 and Arg221 in the binding action.

A new 5α,8α-epidioxysterol, namely yalongsterol A (

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. Graphical Abstract

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.

Four new polyhydroxylated steroids lobophysterols A-D (1-4), together with two known related compounds sarcophytosterol (5) and klyflaccisteroid B (6), were isolated from the South China Sea soft coral Lobophytum sp. Their structures were elucidated on the basis of spectroscopic analysis and by comparison with those reported in the literature. In bioassay, compound 4 showed weak cytotoxicities against HT-29, SNU-398, and Capan-1 cells.

Nine new bicyclic cembranoids, sarcophytrols M–U(1–9), were isolated from the South China Sea soft coral Sarcophyton trocheliophorum as minor components, along with one known related cembranoid 10. Their structures were elucidated by detailed spectroscopic analysis and chemical conversion. The chemical structures of these metabolites are characterized by the different patterns of the additional cyclization within the 14-member skeleton, which leading to the formation of furan, pyran, oxepane, and peroxyl rings, respectively. Among them, sarcophytrols R and S(6 and 7) share a rare decaryiol skeleton with an unusual C12/C15 cyclization. In addition, the absolute configurations of sarcophytrols M and T(1 and 8) were determined by the modified Mosher’s method. The research of these new secondary metabolites provided a further understanding of the diversity of cyclized cembranoids from the title species.

A new brominated polyacetylene, xestonariene I (1), along with three known related analogues (2–4), was obtained from Chinese marine sponge Xestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and by comparison with literature data. Compound 4 exhibited significant inhibitory activity against pancreatic lipase, which plays a key role in preventing obesity, with an IC50 value of 0.61 μM, being comparable to that of the positive control orlistat (IC50 = 0.78 μM).

Minor metabolic components, six new cembranoids sarcophytrols G – L (1 – 6) along with two known related analogues 7 and 8, were isolated from the South China Sea soft coral Sarcophyton trocheliophorum. Their structures were elucidated by extensive spectroscopic analyses (1D- and 2D-NMR, and ESI-MS.) as well as comparison with literature data. As part of our ongoing research project for discovering bioactive substances from Chinese marine invertebrates, compounds 1 – 8 were tested for their inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of Type-II diabetes and obesity. However, none of them exhibited potent PTP1B inhibitory activities. This article is protected by copyright. All rights reserved.

Two new sarsolenane diterpenes, dihydrosarsolenone (2), methyl dihydrosarsolenoneate (3), and two new capnosane diterpenes, sarsolilides B (5) and C (6), were isolated together with the known analogue, sarsolilide A (4), from the Hainan soft coral Sarcophyton trocheliophorum Marenzeller. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data, leading to a structure revision of sarsolenone (1). The absolute configurations of 2 and 5 were determined by TDDFT ECD calculations, and they could be used as ECD reference compounds in the determination of the absolute configuration of their related derivatives. Compounds 4 and 5 exhibited inhibitory activity in vitro against protein tyrosine phosphatases 1B (PTP1B), representing the first report of PTP1B inhibitory activity for capnosane diterpenes.

This review covers structural diversity and biological activities of terpenes from soft corals of the genus of Sarcophyton, reported from 1995 to July, 2011. During this period, besides undefined species, 16 species of the genus Sarcophyton, from different geographical areas, had been chemically examined. Two hundred and five terpenes had been isolated from this genus, including eleven sesquiterpenes, 165 diterpenes, 29 biscembranoids, some of which had novel skeletons. They exhibited various biological features, such as antifeedant, anti-inflammatory, antiviral, and antifouling activities.

A detailed investigation of the South China Sea soft coral Sarcophyton trocheliophorum Marenzeller yielded, along with six known terpenes (6-11), the new sarcophytonolides N-R (1-5), whose structures have been elucidated by detailed spectroscopic analysis. Sarcophytonolides N-R are mono- or bicyclic cembranoids characterized by the presence of three/four double bonds and oxidized methyl groups. Some of the isolated compounds showed significant inhibitory activity against human protein tyrosine phosphatase 1B (PTP1B) enzyme, a key target for the treatment of type-II diabetes and obesity, and some preliminary structure-activity relationships have been drawn. This is the first report on the anti-PTP1B activity of cembrane diterpenoids.

Methyl tortuoate D (1), together with five other known related bis-cembranoids, was isolated from Hainan soft coral Sarcophyton tortuosum. The structure of methyl tortuoate D (1a), firstly isolated and reported by Li et al. from the title organism, was corrected as 1 by an extensive analysis of its one-dimensional and two-dimensional nuclear magnetic resonance data and by comparison with those reported in the literature. In addition, lobophytone K (1b), recently isolated from Hainan soft coral Lobophytum pauciflorum by Lin et al., was proved to be the same compound as 1 and 1a. The absolute configuration of 1 was determined by comparing its electronic circular dichroism curve with that of co-occurring ximaolide A (2).

Two new steroids, (2β,3β,4α,5α,8β)-4-methylergost-24(28)-ene-2,3,8-triol (1) and (3β,7α)-24-methyl-7-hydroperoxycholest-5,24(28)-diene-3-ol (2), together with 13 known analogues (3-15) were isolated from the soft coral Sinularia depressa Tixier-Durivault. The structures of the new compounds were elucidated by detailed spectroscopic analysis and comparison with reported data. In the bioassay in vitro, compounds 3a, 4, and 14 exhibited potent PTP1B inhibitory activity, being similar as that of positive control oleanolic acid. Compound 14 also displayed a notable neuroprotective activity against both amyloid-β(25-35)- and serum deprivation-induced injuries in SH-SY5Y cells while compound 11 showed a considerable antibacterial activity against Staphylococcus aureus. Preliminary structure-activity relationships of these steroids were discussed.

Two new cembranoids, yalongenes A (1) and B (2), were isolated from the South China Sea soft coral Sarcophyton trocheliophorumMarenzeller. Their structures were elucidated by detailed spectroscopic analysis (IR, MS, and NMR) and by comparison with a related model compound. Yalongenes 1 and 2 were evaluated for their cytoprotective effects on SH-SY5Y cell injury induced by H2O2in vitro, and the result showed that only compound 1 had a significant cytoprotective activity at the concentration of 1 μM.

A new brominated polyunsaturated lipid, methyl (E,E)-14,14-dibromo-4,6,13-tetradecatrienoate (1), along with three known related analogues (2–4), were isolated from the Et2O-soluble portion of the acetone extract of Chinese marine sponge Xestospongia testudinaria treated with diazomethane. The structure of the new compound was elucidated by detailed spectroscopic analysis and by comparison with literature data. Compound 3 exhibited significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type II diabetes and obesity, with an IC50 value of 5.30 ± 0.61 μM, when compared to the positive control oleanolic acid (IC50 = 2.39 ± 0.26 μM).

Two new sarsolenane diterpenes, dihydrosarsolenone (2), methyl dihydrosarsolenoneate (3), and two new capnosane diterpenes, sarsolilides B (5) and C (6), were isolated together with the known analogue, sarsolilide A (4), from the Hainan soft coral Sarcophyton trocheliophorum Marenzeller. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data, leading to a structure revision of sarsolenone (1). The absolute configurations of 2 and 5 were determined by TDDFT ECD calculations, and they could be used as ECD reference compounds in the determination of the absolute configuration of their related derivatives. Compounds 4 and 5 exhibited inhibitory activity in vitro against protein tyrosine phosphatases 1B (PTP1B), representing the first report of PTP1B inhibitory activity for capnosane diterpenes.

The genus Xestospongia is one of the most widespread genera of sponges, containing abundant secondary metatolites with novel structures and potent bioactivities. The main structure types of secondary metatolites found in this genus are alkaloids, quinines, terpens, steroids, lipids, polyketones, etc. These metatolites exhibit a variety of bioactivities, such as cytotoxic, antibacterial and antiviral activities. This paper reviews the progress in the chemistry and pharmacological activities of the second metabolities from sponges of Xestospongia, especially for recent five years, with the aim for further research.

This review covers structural diversity and biological activities of terpenes from soft corals of the genus of Sarcophyton, reported from 1995 to July, 2011. During this period, besides undefined species, 16 species of the genus Sarcophyton, from different geographical areas, had been chemically examined. Two hundred and five terpenes had been isolated from this genus, including eleven sesquiterpenes, 165 diterpenes, 29 biscembranoids, some of which had novel skeletons. They exhibited various biological features, such as antifeedant, anti-inflammatory, antiviral, and antifouling activities.