Soft Coral Sarcophyton Trocheliophorum Research Articles

Unprecedented anti-inflammatory biscembranoids with 3-hydroperoxy-3-methylcyclohex-1-ene moiety isolated from aquaculture Sarcophyton trocheliophorum

Recent advancements in the discovery of natural products have made significant progress in rapidly identifying known compounds from complex extracts using advanced spectroscopic technologies. Among these methods, one powerful approach called MS/MS molecular networking (MN) organizes chemical similarity based on MS/MS fragmentation data, serving as a valuable complement to traditional dereplication strategies. In our ongoing research focused on lead discovery from a sustainable medicinal source, an aquaculture soft coral Sarcophyton trocheliophorum, the MN profiling approach revealed the chemical diversity of biscembranoid analogs. By analyzing the MN pattern, biscembranoid derivatives with unique MS/MS fragments were prioritized for further investigation. Two novel biscembranoids, sarcotroxide A (1) and B (2), were successfully obtained through targeted isolation. These novel biscembranes contained an unprecedented 3-hydroperoxy-3-methylcyclohex-1-ene moiety compared with all biscembranoid analogs. The chemical structures of the two new biscembranoids were confirmed through spectroscopic analyses and in silico calculations. Their anti-inflammatory properties were assessed against the generation of superoxide anion (O2•−) and elastase release in activated human neutrophils. Sarcotroxides A (1) and B (2) exhibited anti-inflammatory activity by inhibiting O2•− accumulation (with 43.67% and 61.62% inhibition) and elastase release (with 38.21% and 61.62% inhibition) at 10 µM. These findings validated the potential of these biscembranoids from the cultured S. trocheliophorum as promising candidates for the future development of anti-inflammatory agents specifically designed to target neutrophils.

Physiological and biochemical responses of soft coral Sarcophyton trocheliophorum to doxycycline hydrochloride exposure

In light of the rapid expansion of the marine aquaculture industry, there has been widespread and irregular usage of aquatic drugs to combat biological diseases, which significantly impact the neighboring aquatic ecosystems. This study delves into the impact of the antibiotic aquatic drug known as doxycycline hydrochloride (DOX) on offshore soft corals, providing valuable data for the responsible use and management of aquatic drugs. In this investigation, we subjected Sarcophyton trocheliophorum to acute exposure to varying concentrations of DOX (0, 1, 5, and 10 mg L−1). We meticulously assessed critical parameters and observed alterations in protein levels, superoxide dismutase (SOD) activity, catalase (CAT) activity, lipid peroxidation (LPO), malondialdehyde (MDA) levels, Acid phosphatase (ACP) activity, alkaline phosphatase (AKP) activity, glutathione (GSH) concentration, glutathione S-transferase (GST) activity, glutathione Peroxidase (GSH-Px) activity, zooxanthellae density, and chlorophyll content. Our findings reveal that in the presence of DOX-induced environmental stress, there is a significant increase in LPO, MDA, chlorophyll, carotenoid levels, and the activities of ACP, GST, and GSH-Px in soft corals. Simultaneously, there is a noteworthy decrease in zooxanthellae density. Additionally, the protein concentration and SOD activity in soft corals experience substantial reduction when exposed to 5 mg L−1 DOX. Notably, CAT activity varies significantly in environments with 1 and 10 mg L−1 DOX. Moreover, these conditions exhibit a discernible influence on AKP activity, GSH content, and chlorophyll levels. These findings suggest that DOX exposure carries the potential for toxicity in aquaculture settings, affecting protein synthesis in soft corals and influencing oxidative stress, lipid peroxidation, immunity, and detoxification processes within these organisms. There is also a risk of compromising the coral defense system, potentially leading to coral bleaching. Furthermore, this study underscores the significant impact on photosynthesis, growth, and the metabolic dynamics of the coral-zooxanthellae symbiotic system. Consequently, our research offers vital insights into the mortality and bleaching effects of aquatic drugs on marine corals, offering a foundation for the prudent use and management of such substances.

Structurally Diverse Diterpenes from the South China Sea Soft Coral Sarcophyton trocheliophorum

The present investigation of the South China Sea soft coral Sarcophyton trocheliophorum resulted in the discovery of six new polyoxygenated diterpenes, namely sartrocheliols A-E (1, 3, 5-8) along with four known ones, 2, 4, 9, and 10. Based on extensive spectroscopic data analysis, sartrocheliol A (1) was identified as an uncommon capnosane diterpene, while sartrocheliols B-E (3, 5-8) were established as cembrane diterpenes. They displayed diverse structural features not only at the distinctly different carbon frameworks but also at the various types of heterocycles, including the epoxide, γ-lactone, furan, and pyran rings. Moreover, their absolute configurations were determined by a combination of quantum mechanical-nuclear magnetic resonance (QM-NMR) approach, modified Mosher's method, and X-ray diffraction analysis. In the anti-tumor bioassay, compound 4 exhibited moderate cytotoxic activities against A549, H1975, MDA-MB-231, and H1299 cells with the IC50 values ranging from 26.3 to 47.9 μM.

The Soft Coral Sarcophyton trocheliophorum: A Warehouse of Terpenoids with Structural and Pharmacological Diversity.

The soft coral Sarcophyton trocheliophorum, which was frequently encountered on Indo-Pacific and Red Sea coral reefs, furnished a wealth of secondary metabolites. Notably, terpenoids dominated the chemical profile of this species. In this review, we summarized the discovery of 156 terpenoids from the soft coral S. trocheliophorum specimens in different geographical areas. The structures comprised 13 terpenoidal classes with various functionalities. We covered the era from the first report of S. trocheliophorum-derived metabolites in 1976 up to October 2022. The biological effects of these chemical compositions on a vast array of potential pharmacological activities such as protein tyrosine phosphatase 1B (PTP1B) inhibitory, neuroprotective, cytotoxic, anti-inflammatory, antibacterial, antivirus, and immunomodulatory activities were also presented. This review also revealed an immense demand to explore the terpene biosynthetic gene clusters of this species besides the chemo- and bio-investigations.

Effects of light intensity and photoperiod on the cultivation of the soft coral Sarcophyton trocheliophorum

Coral reefs are one of the most diverse, productive ecosystems in the world, and light plays crucial role in its survival. Notably, the effects of light conditions on soft coral and its adaptive mechanism were unclear. Thus, the present study aimed to investigate and evaluate the effects of different light intensities (30, 80 and 130 μmol m−2 s−1) and photoperiods (18D:6L, 12D:12L and 6D:18L) on cultivation of soft coral Sarcophyton trocheliophorum. During two 50-day of the experiments, we monitored the zooxanthellae density, Chl a content, enzyme activities (SOD, CAT and GST) and microbial diversity of S. trocheliophorum. Our study's outcomes found that, at the end of the experiment, the 80 μmol m−2 s−1 light intensity group and 12D:12L photoperiod group both possessed the highest zooxanthellae density (2.54 × 108 ± 0.14 × 108 cells g−1 DW and 2.40 × 108 ± 0.07 × 108 cells g−1 DW, respectively), Chl a content (295.01 ± 14.13 μg g−1 DW and 287.78 ± 16.13 μg g−1 DW, respectively) and microbial diversity and relatively stable enzyme activities level. Besides, we speculated that the reason for the decline of zooxanthellae density, Chl a content and microbial diversity under other light conditions might be that it induced light stress and caused oxidative damage. The main bacterial composition of S. trocheliophorum in different light conditions was similar at the phylum level, showing the stability of microbial community structure. Proteobacteria, Actinobacteria and Firmicutes were dominant under all light conditions, so we hypothesized that these bacteria phylum play a crucial role in coral growth and survival.In conclusion, compared with the other treatments, 80 μmol m−2 s−1 light intensity and 12D:12L photoperiod were more beneficial to the growth performance of S. trocheliophorum and could be recommended for its cultivation condition. Our study could provide helpful information for sustainable management plans for the cultivation and conservation of soft corals, which was especially important to the protection and restoration of degraded coral reefs.

MS/MS Molecular Networking Unveils the Chemical Diversity of Biscembranoid Derivatives, Neutrophilic Inflammatory Mediators from the Cultured Soft Coral Sarcophyton trocheliophorum

Biscembranoids are the distinctive tetraterpenoids owing a 14/6/14 membered tricyclic scaffold that have been mainly discovered in the soft corals, especially the genera Sarcophyton, Lobophytum and Sinularia. Recent findings have demonstrated the great anti-inflammatory potential of biscembranoid analogues in human neutrophils, motivating more chemical and biological explorations targeting these marine-derived natural products. In the current study, the chemical diversity of biscembranoids derived from the cultured-type Sarcophyton trocheliophorum von Marenzeller was illustrated through MS/MS molecular networking (MN) profiling approach. Based on the MN patterns, the prioritization of unknown biscembranoid derivatives was putatively analyzed. As a result, the biscembrane targeting isolation afforded two new metabolites, sarcotrochelides A (1) and B (2), along with six known analogues (3-8). Their structures and relative configurations were determined by spectroscopic methods. In vitro neutrophil inflammatory inhibition was further investigated for all isolates based on reduced superoxide anion (O2•-) generation detections. Compounds 5-8 showed significant dose-dependently inhibitory effects, suggesting the cruciality of 6,7-dihydrooxepin-2(5H)-one moiety and saturated γ-lactone ring in their reactive oxygen species (ROS)-dependent anti-inflammatory properties.

Bioactive Cembranoids from the Coral Sarcophyton trocheliophorum of Ximao Island.

Eight new cembranoids (sarcophytembranoids A-H, 1-8) and 10 known terpenoids (9-18) were obtained from the soft coral Sarcophyton trocheliophorum of Ximao Island. Notably, 11, 15, and 16 were obtained from a natural source for the first time. The structures of the new isolates were elucidated by extensive spectroscopic analysis, optical rotatory dispersion, and X-ray diffraction experiments. Although the isolated compounds did not show significant activity against the tested tumor cell lines, compounds 3, 7, 8, and 10-15 exhibited anti-inflammatory activities at 10 μM, and compounds 17 and 18 showed moderate protein tyrosine phosphatase 1B inhibition activities with the minimum inhibitory concentrations of 22.19 and 11.26 μM, respectively.

Construction and application of bionic antifouling coatings inspired by soft coral

AbstractMarine biofouling will bring a series of environmental and social problems, which restrict the development and utilisation of marine resources. Therefore, how to prevent biofouling has become a global issue. With the exploration of antifouling methods, bionic antifouling technology with environmentally friendly, broad‐spectrum, and long‐term advantages has gradually attracted people's attention. Inspired by the antifouling strategy of soft coral (Sarcophyton trocheliophorum), the silicone rubber (RTV‐2) with similar elasticity to coral skin was selected as the substrate. The composite structure of the upper transparent layer and the lower porous layer was prepared by simulating the structure of soft coral as the structural factors of the bionic antifouling coatings. Meanwhile, several organic antifouling components with high content contained in soft coral were added to the transparent layer and porous layer, respectively, as the component factors of biomimetic coatings. The bionic antifouling coatings, which are highly consistent with the coral structure, obtained the best antifouling performance under static and dynamic conditions. The above results provide new ideas for the synthesis of environmentally friendly bionic antifouling coatings.

Temporal Variations in the Antifouling Activity of Extract of the Soft Coral Sarcophyton trocheliophorum Collected from the Red Sea

Temporal Variations in the Antifouling Activity of Extract of the Soft Coral Sarcophyton trocheliophorum Collected from the Red Sea

Influence of temperature changes on symbiotic Symbiodiniaceae and bacterial communities’ structure: an experimental study on soft coral Sarcophyton trocheliophorum (Anthozoa: Alcyoniidae)

AbstractIt is well concluded that microbial composition and diversity of coral species can be affected under temperature alterations. However, the interaction of environmental accumulation of corals and temperature stress on symbiotic Symbiodiniaceae and bacterial communities are rarely studied. In this study, two groups of soft coral Sarcophyton trocheliophorum were cultured under constant (26 °C) and inconstant (22 °C to 26 °C) temperature conditions for 30 days as control treatments. After that, water was cooled rapidly to decrease to 20 °C in 24 h. The results of diversity analysis showed that symbiotic Symbiodiniaceae and bacterial communities had a significant difference between the two accumulated groups. The principal coordinate analyses confirmed that symbiotic Symbiodiniaceae and bacterial communities of both control treatments were clustered into two groups. Our results evidenced that rapid cooling stress could not change symbiotic Symbiodiniaceae and bacterial communities’ composition. On the other hand, cooling stress could alter only bacterial communities in constant group. In conclusion, our study represents a clear relationship between environmental accumulation and the impact of short-term cooling stress in which microbial composition structure can be affected by early adaptation conditions.

Diterpenes and sterols from the Red Sea soft coral Sarcophyton trocheliophorum and their cytotoxicity and anti-leishmanial activities

The ethyl acetate and dichloromethane-soluble fractions, from a soft coral Sarcophyton trocheliophorum total methanolic extract, exhibited significant anti-leishmanial and cytotoxic activities. These active fractions yielded a new cembranoid diterpene (1), two known analogues [sarcotrocheliol (2) and sarcophine (3)], and two sterols [(24S)-24-methylcholesterol (4) and gorgosterol (5)]. The structure of the new diterpene (1) was determined via a detailed analysis of its spectroscopic data. Compounds 3 and 5 demonstrated noticeable cytotoxicity on A549 (IC50 17.4 ± 1.9 µg/ml) and HepG2 (IC50 17.7 ± 1.5 µg/ml) cell lines, respectively. None of the isolates 1‒5 showed detectable anti-leishmanial activity (IC50 >100 µg/ml).

Four new cembranoids from the South China Sea soft coral Sarcophyton trocheliophorum

Four new cembrane diterpenes, 1,13-di-epi-13-acetoxy launine P (1), 13-oxo-thunbergol (2), isocrassumol B (3) and 7α, 8α-sarcophine (4), together with two known launine P (5) and sarcophytonin B (6), were isolated from the extract of the South China Sea soft coral Sarcophyton trocheliophorum. The structures were elucidated by spectroscopic analysis, ECD analysis and comparison with literature data. All compounds were tested for their antimicrobial activity and antiviral activity. Compounds 1, 2 and 5 were found to exhibit weak antibacterial activity, while 6 showed strong inhibition activity against Staphylococcus aureus and Bacillus subtilis (MIC＜0.5 µg/mL). Compounds 2 showed moderate inhibitory effect against influenza A viruses H1N1 with IC50 of 17.8 μM.

New Naturally Occurring Compounds from Sarcophyton trocheliophorum

Corals are rich sources of secondary metabolites used as chemical defense compounds against predators. The production of diverse metabolites has characterized soft corals belonging to the genus Sarcophyton. However, phenolic compounds are slightly rare in soft corals. Through a further bioassay-guided fractionation for the chloroform-soluble extract of soft coral Sarcophyton trocheliophorum, collected from the Red Sea, three closely related phenolic compounds: 2,4-di-tert-butyl-6-nitro-phenol (1), 2,4-di-tert-butyl-phenol (2), and 2,4-bis(1-methyl-1-phenylethyl)-phenol (3), along with the wax tricosyldocosanoiate (4) were isolated herein for the first time from nature in addition to cholesterol. Structures of the isolated compounds 1-4 were identified by NMR spectroscopy (1H, 13C, 1H,1H COSY, HMQC and HMBC) and mass spectrometry (EI, HRESI-MS) for the first time so far. The antimicrobial activities of the soft coral extract, along with the isolated compounds, were evaluated against Staphylococcus aureus, Bacillus subtilis ATCC6051, Streptomyces viridochromogenes Tü 57, Escherichia coli, Mucor miehei Tü 284, Candida albicans, and the green alga Chlorella vulgaris. The crude extract exhibited a moderate activity against Streptomyces viridochromogenes Tü 57 (12 mm) at a concentration of 400 µg/disc, while the reported compounds 1-4 showed no activity against the reported test microorganisms at a concentration of 40 µg/disc.

Further new cembranoids from the South China Sea soft coral Sarcophyton trocheliophorum

Two new cembranoids, ximaosarcophytols A (1) and B (2), together with three related known ones (3–5), were isolated from the soft coral Sarcophyton trocheliophorum collected off the Ximao Island, Hainan Province, China. Their structures including the absolute configurations were elucidated by extensive spectroscopic analysis, TDDFT/ECD (time-dependent density functional theory/electronic circular dichroism) calculations and comparison with the reported data.

Novel Anti-fouling Strategies of Live and Dead Soft Corals (Sarcophyton trocheliophorum): Combined Physical and Chemical Mechanisms

At present, biomimetic antifouling research objects are mostly concentrated on the fast-moving marine organism, but the anti-fouling effect of the low-speed or static marine equipment is not obvious. This paper describes the anti-fouling mechanism of soft coral (Sarcophyton trocheliophorum), including the physical defense mechanism and the bactericidal ability of mucus and coral powder. As a sessile organisms, soft coral lacks escape mechanism. Therefore, the study on its antibacterial strategy is significant because it can provide theoretical guidance for static antifouling. Results showed that the live soft coral would molt in unfriendly environment, and the secreted mucus could defend themselves against fouling microorganism. Then, Liquid Chromatography-Mass Spectrometry (LC-MS) analysis was conducted to identify the bioactive compounds of the coral powder and mucus. Results revealed that both powder and mucus contained a wide variety of toxic components, which had bactericidal effects. Moreover, at the same concentration, the inhibitory effect of the main components on Gram-negative bacteria was stronger than that on positive bacteria. These findings enhance the understanding about the antifouling mechanism of soft coral and provide new ideas for design and prepare novel antifouling strategy to combat biofouling under static condition.

Immunomodulatory Biscembranoids and Assignment of Their Relative and Absolute Configurations: Data Set Modulation in the Density Functional Theory/Nuclear Magnetic Resonance Approach.

Five new biscembranoids, bistrochelides A-E (3-7), were isolated together with glaucumolides A (1) and B (2) from the soft coral Sarcophyton trocheliophorum. Their structures and absolute configurations were determined by spectroscopic methods, X-ray crystal diffraction, and DFT/NMR (density functional theory/nuclear magnetic resonance) and TDDFT/ECD (time-dependent density functional theory/electronic circular dichroism) calculations. A new approach is introduced to determine the relative configuration of a stereocenter through the dynamic evaluation of the mean absolute errors (MAEs) between the investigated diastereoisomers, moving from an "extended" to a more diagnostic "restricted" set of atoms. This research leads to the structure revision of glaucumolides A and B. In in vitro immunomodulatory screening, compounds 1 and 4 significantly induced the proliferation of CD3+ T cells, while compounds 1 and 5 significantly increased the CD4+/CD8+ ratio at 3 μM.

Structural, stereochemical, and bioactive studies of cembranoids from Chinese soft coral Sarcophyton trocheliophorum

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 ε-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 as a PTP1B Inhibitor from Hainan Soft Coral Sarcophyton trocheliophorum Marenzeller

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.

Sarcophytrols G-L, Novel Minor Metabolic Components from South China Sea Soft Coral Sarcophyton trocheliophorum Marenzeller.

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-, 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.

New Bicyclic Cembranoids from the South China Sea Soft Coral Sarcophyton trocheliophorum

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.