Bioactive polyhydroxylated steroids from the Hainan soft coral Sinularia depressa Tixier-Durivault

Cytotoxic metabolites from Sinularia levi supported by network pharmacology

The in-vitro anti-proliferative evaluation of Sinularia levi total extract against three cell lines revealed its potent effect against Caco-2 cell line with IC50 3.3 μg/mL, followed by MCF-7 and HepG-2 with IC50 6.4 μg/mL and 8.5 μg/mL, respectively, in comparison to doxorubicin. Metabolic profiling of S. levi total extract using liquid chromatography coupled with high-resolution electrospray ionization mass spectrometry (LC-HR-ESI-MS) revealed the presence of phytoconstituents clusters consisting mainly of steroids and terpenoids (1-20), together with five metabolites 21-25, which were additionally isolated and identified through the phytochemical investigation of S. levi total extract through various chromatographic and spectroscopic techniques. The isolated metabolites included one sesquiterpene, two steroids and two diterpenes, among which compounds prostantherol (21) and 12-hydroperoxylsarcoph-10-ene (25) were reported for the first time in Sinularia genus. The cytotoxic potential evaluation of the isolated compounds revealed variable cytotoxic effects against the three tested cell lines. Compound 25 was the most potent with IC50 value of 2.13 ± 0.09, 3.54 ± 0.07 and 5.67 ± 0.08 μg/mL against HepG-2, MCF-7 and Caco-2, respectively, followed by gorgosterol (23) and sarcophine (24). Additionally, network analysis showed that cyclin-dependent kinase 1 (CDK1) was encountered in the mechanism of action of the three cancer types. Molecular docking analysis revealed that CDK1 inhibition could possibly be the reason for the cytotoxic potential.

Two new compounds from the Hainan Soft Corals Sinularia tumulosa and Sinularia depressa with their anti-inflammatory or cytotoxic activities

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 IC50 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 IC50 value of 9.5 µM.

Natural Bioactive Compounds from Marine Invertebrates That Modulate Key Targets Implicated in the Onset of Type 2 Diabetes Mellitus (T2DM) and Its Complications

BACKGROUND

Type 2 diabetes mellitus (T2DM) is an ongoing, risky, and costly health problem that therefore always requires new treatment options. Moreover, although several drugs are available, only 36% of patients achieve glycaemic control, and patient adherence is a major obstacle. With monotherapy, T2DM and its comorbidities/complications often cannot be managed, and the concurrent administration of several hypoglycaemic drugs is required, which increases the risk of side effects. In fact, despite the efficacy of the drugs currently on the market, they generally come with serious side effects. Therefore, scientific research must always be active in the discovery of new therapeutic agents.

DISCUSSION

The present review highlights some of the recent discoveries regarding marine natural products that can modulate the various targets that have been identified as crucial in the establishment of T2DM disease and its complications, with a focus on the compounds isolated from marine invertebrates. The activities of these metabolites are illustrated and discussed.

OBJECTIVES

The paper aims to capture the relevant evidence of the great chemical diversity of marine natural products as a key tool that can advance understanding in the T2DM research field, as well as in antidiabetic drug discovery. The variety of chemical scaffolds highlighted by the natural hits provides not only a source of chemical probes for the study of specific targets involved in the onset of T2DM, but is also a helpful tool for the development of drugs that are capable of acting via novel mechanisms. Thus, it lays the foundation for the design of multiple ligands that can overcome the drawbacks of polypharmacology.

Lobosteroids A-F: Six New Highly Oxidized Steroids from the Chinese Soft Coral Lobophytum sp

To explore the steroidal constituents of the soft coral Lobophytum sp. at the coast of Xuwen County, Guangdong Province, China, a chemical investigation of the above-mentioned soft coral was carried out. After repeated column chromatography over silica gel, Sephadex LH-20, and reversed-phase HPLC, six new steroids, namely lobosteroids A-F (1-6), along with four known compounds 7-10, were obtained. Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data reported in the literature. Among them, the absolute configuration of 1 was determined by X-ray diffraction analysis using Cu Kα radiation. These steroids were characterized by either the presence of an α,β-α',β'-unsaturated carbonyl, or an α,β-unsaturated carbonyl moiety in ring A, or the existence of a 5α,8α-epidioxy system in ring B, as well as diverse oxidation of side chains. The antibacterial bioassays showed that all isolated steroids exhibited significant inhibitory activities against the fish pathogenic bacteria Streptococcus parauberis FP KSP28, Phoyobacterium damselae FP2244, and Streptococcus parauberis SPOF3K, with IC90 values ranging from 0.1 to 11.0 µM. Meanwhile, compounds 2 and 6-10 displayed potent inhibitory effects against the vancomycin-resistant Enterococcus faecium bacterium G7 with IC90 values ranging from 4.4 to 18.3 µM. Therefore, ten highly oxidized steroids with strong antibacterial activities were isolated from the Chinese soft coral Lobophytum sp., which could be developed as new chemotypes of antibacterial drug leads.

Unlocking the Potential of Octocoral-Derived Secondary Metabolites against Neutrophilic Inflammatory Response

Inflammation is a critical defense mechanism that is utilized by the body to protect itself against pathogens and other noxious invaders. However, if the inflammatory response becomes exaggerated or uncontrollable, its original protective role is not only demolished but it also becomes detrimental to the affected tissues or even to the entire body. Thus, regulating the inflammatory process is crucial to ensure that it is resolved promptly to prevent any subsequent damage. The role of neutrophils in inflammation has been highlighted in recent decades by a plethora of studies focusing on neutrophilic inflammatory diseases as well as the mechanisms to regulate the activity of neutrophils during the overwhelmed inflammatory process. As natural products have demonstrated promising effects in a wide range of pharmacological activities, they have been investigated for the discovery of new anti-inflammatory therapeutics to overcome the drawbacks of current synthetic agents. Octocorals have attracted scientists as a plentiful source of novel and intriguing marine scaffolds that exhibit many pharmacological activities, including anti-inflammatory effects. In this review, we aim to provide a summary of the neutrophilic anti-inflammatory properties of these marine organisms that were demonstrated in 46 studies from 1995 to the present (April 2023). We hope the present work offers a comprehensive overview of the anti-inflammatory potential of octocorals and encourages researchers to identify promising leads among numerous compounds isolated from octocorals over the past few decades to be further developed into anti-inflammatory therapeutic agents.

Sinulasterols D-G, four new antibacterial steroids from the South China sea soft coral Sinularia depressa

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).

Enzyme Inhibitors from Gorgonians and Soft Corals

For decades, gorgonians and soft corals have been considered promising sources of bioactive compounds, attracting the interest of scientists from different fields. As the most abundant bioactive compounds within these organisms, terpenoids, steroids, and alkaloids have received the highest coverage in the scientific literature. However, enzyme inhibitors, a functional class of bioactive compounds with high potential for industry and biomedicine, have received much less notoriety. Thus, we revised scientific literature (1974-2022) on the field of marine natural products searching for enzyme inhibitors isolated from these taxonomic groups. In this review, we present representative enzyme inhibitors from an enzymological perspective, highlighting, when available, data on specific targets, structures, potencies, mechanisms of inhibition, and physiological roles for these molecules. As most of the characterization studies for the new inhibitors remain incomplete, we also included a methodological section presenting a general strategy to face this goal by accomplishing STRENDA (Standards for Reporting Enzymology Data) project guidelines.

Chemistry and bioactivity of secondary metabolites from South China Sea marine fauna and flora: recent research advances and perspective

Marine organisms often produce a variety of metabolites with unique structures and diverse biological activities that enable them to survive and struggle in the extremely challenging environment. During the last two decades, our group devoted great effort to the discovery of pharmaceutically interesting lead compounds from South China Sea marine plants and invertebrates. We discovered numerous marine secondary metabolites spanning a wide range of structural classes, various biosynthetic origins and various aspects of biological activities. In a series of reviews, we have summarized the bioactive natural products isolated from Chinese marine flora and fauna found during 2000-2012. The present review provides an updated summary covering our latest research progress and development in the last decade (2012-2022) highlighting the discovery of over 400 novel marine secondary metabolites with promising bioactivities from South China Sea marine organisms.

Sinuhirtone A, An Uncommon 17,19-Dinorxeniaphyllanoid, and Nine Related New Terpenoids from the Hainan Soft Coral Sinularia hirta

Chemical investigation of the Hainan soft coral Sinularia hirta resulted in the isolation and identification of a library of sixteen structurally diverse terpenoids, including a dinorditerpenoid with an uncommon 17,19-dinorxeniaphyllane skeleton, namely sinuhirtone A (7), six new xeniaphyllane-type diterpenoids (1–6), one new norxeniaphyllanoid (8), two new norcaryophyllene-type sesquiterpenoids (9 and 10), together with six known related compounds (11–16). Compounds 1–3 are three new furanone-containing xeniaphyllane-type diterpenoids. The structures of the new compounds, including their absolute configurations, were determined by extensive spectroscopic analysis and a series of quantum chemical calculations, including quantum mechanical-nuclear magnetic resonance (QM–NMR), time-dependent density functional theory–electronic circular dichroism (TDDFT–ECD), and optical rotatory dispersion (ORD) methods. A plausible biosynthetic connection between new compounds 1–9 was also proposed. New compounds 2–4, 7, and 8 were evaluated for in vitro cytotoxicity against four cancer cell lines.

Chemical Evaluation, Antioxidant, Antiproliferative, Anti-Inflammatory and Antibacterial Activities of Organic Extract and Semi-Purified Fractions of the Adriatic Sea Fan, Eunicella cavolini

Due to sedentary lifestyle and harsh environmental conditions, gorgonian coral extracts are recognized as a rich source of novel compounds with various biological activities, of interest to the pharmaceutical and cosmetic industries. The presented study aimed to perform chemical screening of organic extracts and semi-purified fractions obtained from the common Adriatic gorgonian, sea fan, Eunicella cavolini (Koch, 1887) and explore its abilities to exert different biological effects in vitro. Qualitative chemical evaluation revealed the presence of several classes of secondary metabolites extended with mass spectrometry analysis and tentative dereplication by using Global Natural Product Social Molecular Networking online platform (GNPS). Furthermore, fractions F4 and F3 showed the highest phenolic (3.28 ± 0.04 mg GAE/g sample) and carotene (23.11 ± 2.48 mg β-CA/g sample) content, respectively. The fraction F3 inhibited 50% of DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and ABTS (2,2′-azino-bis (3-ethylbenzthiazolin-6-yl) sulfonic acid) radicals at the concentrations of 767.09 ± 11.57 and 157.16 ± 10.83 µg/mL, respectively. The highest anti-inflammatory potential was exhibited by F2 (IC₅₀ = 198.70 ± 28.77 µg/mL) regarding the inhibition of albumin denaturation and F1 (IC₅₀ = 254.49 ± 49.17 µg/mL) in terms of soybean lipoxygenase inhibition. In addition, the most pronounced antiproliferative effects were observed for all samples (IC₅₀ ranging from 0.82 ± 0.14–231.18 ± 46.13 µg/mL) against several carcinoma cell lines, but also towards non-transformed human fibroblasts pointing to a generally cytotoxic effect. In addition, the antibacterial activity was tested by broth microdilution assay against three human pathogenic bacteria: Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The latter was the most affected by fractions F2 and F3. Finally, further purification, isolation and characterization of pure compounds from the most active fractions are under investigation.

New lobane-type diterpenoids from the Xisha soft coral Sinularia polydactyla

Lobane-type diterpenoids are not frequently discovered from marine soft corals. In this paper, three new lobane type diterpenes, 13-methoxyloba-8,10,15(16),17(18)-tetraene (1), 8,10,13(15)Z,16E-lobatetraene (2) and 19-hydroxy-lobatetraene (3), and a new natural compound, 17,18-epoxyloba-16-acetoxy-8,10,13(15)-trien (4), co-occurring with a known related diterpenoid, 18-methoxyloba-8,10,13(15),16(17)-tetraene (5), were isolated from the South China Sea soft coral Sinularia polydactyla. The structures of new compounds were determined by extensive spectroscopic analysis and by comparison with those reported in the literature. In bioassay, all the isolates were inactive on antibacterial, PTP1B inhibitory, and immunological activities. This study increased the chemical diversity of marine diterpenoids.

Chemical Diversity and Biological Activity of Secondary Metabolites from Soft Coral Genus Sinularia since 2013

Sinularia is one of the conspicuous soft coral species widely distributed in the world’s oceans at a depth of about 12 m. Secondary metabolites from the genus Sinularia show great chemical diversity. More than 700 secondary metabolites have been reported to date, including terpenoids, norterpenoids, steroids/steroidal glycosides, and other types. They showed a broad range of potent biological activities. There were detailed reviews on the terpenoids from Sinularia in 2013, and now, it still plays a vital role in the innovation of lead compounds for drug development. The structures, names, and pharmacological activities of compounds isolated from the genus Sinularia from 2013 to March 2021 are summarized in this review.

Sinulasterols A-C, three new bioactive oxygenated steroids from the South China Sea soft coral Sinularia depressa

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 (IC₅₀ = 12.1 μM), which was analogous to the positive control dexamethasone (IC₅₀ = 8.7 μM), metabolites 1 and 2 displayed a moderate inhibitory activity (IC₅₀ 51.1 μM and 22.7 μM respectively).

Two new hydroperoxy steroids from the South China Sea gorgonian Rumphella sp

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.

Secondary Metabolites from Gorgonian Corals of the Genus Eunicella: Structural Characterizations, Biological Activities, and Synthetic Approaches

Gorgonian corals, which belong to the genus Eunicella, are known as natural sources of diverse compounds with unique structural characteristics and interesting bioactivities both in vitro and in vivo. This review is focused primarily on the secondary metabolites isolated from various Eunicella species. The chemical structures of 64 compounds were divided into three main groups and comprehensively presented: a) terpenoids, b) sterols, and c) alkaloids and nucleosides. The observed biological activities of depicted metabolites with an impact on cytotoxic, anti-inflammatory, and antimicrobial activities were reviewed. The most promising biological activities of certain metabolites point to potential candidates for further development in pharmaceutical, cosmetic, and other industries, and are highlighted. Total synthesis or the synthetic approaches towards the desired skeletons or natural products are also summarized.

New cytotoxic ergostane-type sterols from the Chinese soft coral Sinularia sp

Two new highly oxygenated ergostane-type sterols (1, 2) together with one known related compound sinugrandisterol A (3) were isolated from the soft coral Sinularia sp. collected from the water area near the Xisha Islands, South China Sea. Their structures were elucidated on the basis of detailed spectroscopic analysis, chemical transformations, and by comparison with those reported in literature. In bioassays, compounds 1 and 2 showed in vitro antiproliferative activity against a panel of cancer cell lines, including MDA-MB-436, A549, Hep3B, HT-29 and H157. Morphological observation and Hoechst 33,258 staining assays showed that compound 1-treated H157 cells displayed apoptosis characteristics. Moreover, western blot assays suggested that 1 could increase the expression of Bax and down-regulate expression of Bcl-2.

A new 5α,8α-epidioxysterol with immunosuppressive activity from the South China Sea soft coral Sinularia sp

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].

Cytotoxic polyhydroxylated steroids from the South China Sea soft coral Lobophytum sp

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.

Protein tyrosine phosphatase 1B inhibitors from natural sources

Since PTP1B enzyme was discovered in 1988, it has captured the research community's attention. This landmark discovery has stimulated numerous research studies on a variety of human diseases, including cancer, inflammation, and diabetes. Tremendous progress has been made in finding PTP1B inhibitors and exploring PTP1B regulatory mechanisms. This review investigates for the natural PTP1B inhibitors, and focuses on the common characteristics of the discovered structures and structure-activity relationships. To facilitate understanding, all the natural compounds are here divided into five different classes (fatty acids, phenolics, terpenoids, steroids, and alkaloids), according to their skeletons. These PTP1B inhibitors of scaffold structures could serve as a theoretical basis for new concept drug discovery and design.

Further brominated polyacetylenes with pancreatic lipase inhibitory activity from Chinese marine sponge Xestospongia testudinaria

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).

Inhibitors of Protein Tyrosine Phosphatase 1B from Marine Natural Products

The ocean is a capacious area with the most abundant biological resources on the earth. The particularity of the marine ecological environment (high pressure, high salt, and hypoxia) makes the marine species survival competition fiercely, forcing many marine organisms in the process of life to produce a great deal of secondary metabolites with special structures and biological activities. In this article, 118 natural products which were isolated from four kinds of marine organisms, sponges, algae, soft corals and fungus, showing PTP1B inhibitory activity were summarized from 2010 to 2016, which may become the leading compounds towards treating Diabetes mellitus (DM). What's more, we briefly summarized the structure-activity relationship of PTP1B inhibitors.

Soft coral Cespitularia stolonifera: New cytotoxic ceramides and gastroprotective activity

In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol (1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol (2), 24-methylcholesta-5, 24(28)-diene-3β-acetate (3), 4-methyl-24-methylcholesta-22-ene-3-ol (4), and cholesterol, was isolated and characterized from CH₂Cl₂/MeOH extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate (1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NMR, HRESI-MS, and GC-MS, in addition of chemical methods. (-)-Alloaromadendren, ledane, (1)-alloaromadendren oxide, isoaromadendrene epoxide and (-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides (1) and (1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids (2) and (3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The CH₂Cl₂/MeOH extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.

Bioactive Steroids from the Formosan Soft Coral Umbellulifera petasites

Three new steroids, petasitosterones A and B (1 and 2) and a spirosteroid petasitosterone C (3), along with eight known steroids (4–11), were isolated from a Formosan marine soft coral Umbellulifera petasites. The structures of these compounds were elucidated by extensive spectroscopic analysis and comparison of spectroscopic data with those reported. Compound 3 is a marine steroid with a rarely found A/B spiro[4,5]decane ring system. Compounds 1–3 and 5 displayed inhibitory activity against the proliferation of a limited panel of cancer cell lines, whereas 2 and 5 exhibited significant anti-inflammatory activity to inhibit nitric oxide (NO) production. The inhibitory activities for superoxide anion generation and elastase release of compounds 1–11 were also examined to evaluate the anti-inflammatory potential, and 2–4 were shown to exhibit significant activities.

Recent advances in the development of protein tyrosine phosphatase 1B inhibitors for Type 2 diabetes

Diabetes mellitus is the most serious and prevalent metabolic disorders worldwide, complications of which can decrease significantly the quality of life and contribute to premature death. Resistance to insulin is a predominant pathophysiological factor of Type 2 diabetes (T2D). Protein tyrosine phosphatase 1B (PTP1B) is an important negative factor of insulin signal and a potent therapeutic target in T2D patients. This review highlights recent advances (2012-2015) in research related to the role of PTP1B in signal transduction processes implicated in pathophysiology of T2D, and novel PTP1B inhibitors with an emphasis on their chemical structures and modes of action.

Oxysterols from an octocoral of the genus Gorgonia from the eastern Pacific of Panama

Eighteen new oxysterols were isolated from a previously undescribed octocoral of the genusGorgonia. Antimicrobial and antileishmanial properties of these compounds have been evaluated.

Marine natural products

This review covers the literature published in 2013 for marine natural products (MNPs), with 982 citations (644 for the period January to December 2013) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1163 for 2013), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

Structural diversity of terpenoids in the soft coral Sinularia flexibilis, evidenced by a collection from the South China Sea

Eight new terpenoids, including a rare biscembranoid and a 15-membered macrocyclic diterpenoid, were isolated from South China Sea soft coral Sinularia flexibilis.

Thunberol, a new sterol from the Chinese brown alga Sargassum thunbergii

A new sterol, named thunberol (1), along with four known analogs, 24-ethylcholesta-4,24(28)-dien-3-one (2), stigmasta-5,28-dien-3β-ol (3), cholesta-5,14-dien-3β-ol (4), and cholesta-5,23-dien-3β,25-diol (5), were isolated from the brown alga Sargassum thunbergii collected from East China Sea. The structures of these metabolites were elucidated on the basis of detailed spectroscopic analysis and by comparison with the literature data. Thunberol (1) exhibited significant inhibitory activity against protein tyrosine phosphatase 1B, a potential drug target for the treatment of Type-II diabetes and obesity, with an IC50 value of 2.24 μg/ml.

Bioactive marine drugs and marine biomaterials for brain diseases

Marine invertebrates produce a plethora of bioactive compounds, which serve as inspiration for marine biotechnology, particularly in drug discovery programs and biomaterials development. This review aims to summarize the potential of drugs derived from marine invertebrates in the field of neuroscience. Therefore, some examples of neuroprotective drugs and neurotoxins will be discussed. Their role in neuroscience research and development of new therapies targeting the central nervous system will be addressed, with particular focus on neuroinflammation and neurodegeneration. In addition, the neuronal growth promoted by marine drugs, as well as the recent advances in neural tissue engineering, will be highlighted.

Synthesis of 24(28)-Methylene-1α-Hydroxyvitamin D3, a Novel Vitamin D3 Analogue

24(28)-Methylene-1α-hydroxyvitamin D3 was synthesised in 13 steps from vitamin D2. The key step of the synthesis involved the Wittig–Horner olefination of a nor-vitamin D2 aldehyde with diethylphosphono-3-methyl-2-butanone. The resulting enone was followed by reduced methylenation, photoisomerisation and deprotection then gave the target compound.