Discovery of nitrogenous sesquiterpene quinone derivatives from sponge Dysidea septosa with anti-inflammatory activity in vivo zebrafish model

Anti-inflammatory and cytotoxicity nitrogenous merosesquiterpenoids from the sponge Pseudoceratina purpurea

Fourteen undescribed nitrogenous merosesquiterpenoids, purpurols A-D (1-4) and puraminones A-J (5-14), along with three known related compounds (15-17) were isolated from the sponge Pseudoceratina purpurea collected in the South China Sea. Their structures and absolute configurations were unambiguously elucidated by a combination of spectroscopic data, X-ray diffraction analysis, electronic circular dichroism calculations, and chemical derivatization. Purpurols A-D (1-4) incorporated nitrogenous heterocycles, compounds 1 and 2 feature an unusual benzothiazole ring, while 3 and 4 feature benzoxazole ring. Puraminones A-J (5-14) represent sesquiterpenoid aminoquinones with different amine and amino acid side chains at C-20. Additionally, twenty unreported sesquiterpenoid aminoquinone analogues were obtained through chemical derivatization. It is worth noting that all compounds are featured with unusual rearranged 4,9-friedodrimane subunit. In the bioassays, purpurols A and B showed weak anti-inflammation in zebrafish, as well as some compounds showed activities against tumor cells, therefore, preliminary structure-cytotoxicity relationships are also discussed.

Potential of natural products in inflammation: biological activities, structure-activity relationships, and mechanistic targets

A balance between the development and suppression of inflammation can always be found in the body. When this balance is disturbed, a strong inflammatory response can damage the body. It sometimes is necessary to use drugs with a significant anti-inflammatory effect, such as nonsteroidal anti-inflammatory drugs and steroid hormones, to control inflammation in the body. However, the existing anti-inflammatory drugs have many adverse effects, which can be deadly in severe cases, making research into new safer and more effective anti-inflammatory drugs necessary. Currently, numerous types of natural products with anti-inflammatory activity and distinct structural features are available, and these natural products have great potential for the development of novel anti-inflammatory drugs. This review summarizes 260 natural products and their derivatives with anti-inflammatory activities in the last two decades, classified by their active ingredients, and focuses on their structure-activity relationships in anti-inflammation to lay the foundation for subsequent new drug development. We also elucidate the mechanisms and pathways of natural products that exert anti-inflammatory effects via network pharmacology predictions, providing direction for identifying subsequent targets of anti-inflammatory natural products.

A new capnosane-type diterpenoid from the South China sea soft coral Lobophytum pauciflorum

A new rare capnosane-type diterpenoid (1) along with two known compounds sarcophyolides D (2) and arbolide C (3), were isolated from the soft coral Lobophytum pauciflorum collected at Xisha Islands in the South China Sea. The structure of 1 was established based on comprehensive spectroscopic data, literature comparison, and quantum chemical calculations. Compound 1 exhibited moderate anti-inflammatory activities in the zebrafish model at a concentration of 20 μM.

Pseudoceranoids A-J, Sesquiterpene-Based Meroterpenoids with Cytotoxicity from the Sponge Pseudoceratina purpurea

Pseudoceranoid A (1), a rare merosesquiterpene featuring a rearranged 4,9-friedodrimane-type core with a crotonolactone moiety, two new rearranged 4,9-friedodrimane-type sesquiterpene cyclopentanones (2 and 3), and three new rearranged 4,9-friedodrimane-type sesquiterpene hydroquinones (4-6), along with two new drimane-type sesquiterpene derivatives (7 and 8), as well as two new 4,9-friedodrimane-type sesquiterpene quinones (9 and 10), were isolated from the South China Sea sponge Pseudoceratina purpurea. The structures of compounds were established by analysis of spectroscopic data, as well as by single-crystal X-ray diffraction, DP4+ probability analyses, and calculated electronic circular dichroism. Compound 4 showed weak cytotoxicity against K562, H69AR, and MDAMB-231 cell lines with IC50 values of 3.01, 7.74, and 9.82 μM, respectively. Compound 5 exhibited cytotoxicity against the H69AR cell line with an IC50 value of 2.85 μM.

Natural sesquiterpene quinone/quinols: chemistry, biological activity, and synthesis

Covering: 2010 to 2021Sesquiterpene quinone/quinols (SQs) are characterized by a C15-sesquiterpenoid unit incorporating a C6-benzoquinone/quinol moiety. Numerous unprecedented carbon skeletons have been constructed with various connection patterns between the two parts. The potent anti-cancer, anti-inflammatory, anti-microbial, anti-viral, and fibrinolytic activities of SQs are associated with their diverse structures. The representative avarol has even entered the stage of clinical phase II research as an anti-HIV agent, and was developed as paramedic medicine against psoriasis. This review provides an overall summary of 558 new natural SQs discovered between 2010 and 2021, including seven groups and sixteen structure-type subgroups, which comprehensively recapitulates their chemical structures, spectral characteristics, source organisms, biological activities, synthesis, and biosynthesis, aiming to expand the application scope of this unique natural product resource.

Preparation and Characterization of Ginger Peel Polysaccharide-Zn (II) Complexes and Evaluation of Anti-Inflammatory Activity

The present study aimed to explore the improvement of the bioactivity of ginger peel polysaccharides (GPs) by the modification of zinc after structural characterization. The obtained GP-Zn (II) complexes consisted dominantly of glucose and galactose in a mass proportion of 95.10:2.10, with a molecular weight of 4.90 × 10⁵ Da and a Zn content of 21.17 mg/g. The chelation of GPs and Zn (II) was mainly involved in the O-H of hydroxyl groups, and this interaction reduced the crystallinity and decreased the asymmetry of GPs, with a slight effect on the thermal stability. The administration of GPs and their Zn (II) complexes effectively alleviated CuSO₄-induced inflammatory response in zebrafish (Tg: zlyz-EGFP) via down-regulating the mRNA expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-12 and TNF-α) and upregulating the expression of anti-inflammatory cytokine (IL-10). Furthermore, the modification of Zn (II) enhanced the inflammation-inhibiting effect of polysaccharides. Therefore, GP-Zn (II) complexes could be applied as a candidate anti-inflammatory agent for the treatment of chronic inflammation-related diseases.

Anti-inflammatory sesquiterpene and triterpene acids from Mesona procumbens Hemsley

Mesonaprocumbens Hemsley is a plant conventionally processed to provide popular food materials and herbal medicines in Asia. In this study, six triterpene acids, including five new ones (mesonaic acids D-H, 1–5), and one proximadiol-type sesquiterpene (7) were isolated from the methanolic extract of the air-dried M. procumbens. Chemical structures of 1‒7 were established by spectroscopic methods, especially 2D NMR techniques (1H–1H COSY, HSQC, HMBC, and NOESY) and HRESIMS. Concerning their biological activities, compounds 1, 2, 6, and 7 were examined manifesting high inhibition toward the pro-inflammatory NO production with EC50 values ranging from 12.88 to 21.21 µM, outrunning the positive control quercetin (24.12 µM). The mesoeudesmol B (7) identified from M. procumbens is the very first example, which exhibited high anti-inflammatory activity diminishing the level of the lipopolysaccharide-induced NO in RAW264.7 macrophage cells, thereby suppressing the secretion of pro-inflammatory cytokines TNF-α and IL-6 and the level of two critical downstream inflammatory mediators iNOS and COX-2.

Anti-Inflammatory Effects of Natural Products on Cerebral Ischemia

Cerebral ischemia with high mortality and morbidity still requires the effectiveness of medical treatments. A growing number of investigations have shown strong links between inflammation and cerebral ischemia. Natural medicine’s treatment methods of cerebral ischemic illness have amassed a wealth of treatment experience and theoretical knowledge. This review summarized recent progress on the disease inflammatory pathways as well as 26 representative natural products that have been routinely utilized to treat cerebral ischemic injury. These natural products have exerted anti-inflammatory effects in cerebral ischemia based on their inflammatory mechanisms, including their inflammatory gene expression patterns and their related different cell types, and the roles of inflammatory mediators in ischemic injury. Overall, the combination of the potential therapeutic interventions of natural products with the inflammatory mechanisms will make them be applicable for cerebral ischemic patients in the future.

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

Four new polyhydroxylated steroids lobophysterols E–H (1–4), together with three known compounds (5–7), were isolated from the soft coral Lobophytum pauciflorum collected at Xisha Island, China. The structures of the new compounds were elucidated by extensive spectroscopic analysis and comparison with NMR data of structurally related compounds reported in the literature. The absolute configuration of 1–3 was determined by X-ray diffraction. All the compounds have assessed the cytotoxicity against HL-60, K562, and Hela cells. Compound 1 showed weak cytotoxicity against K562 cells with an IC50 value of 19.03 μM. In addition, compound 1 also showed a moderate anti-inflammatory effect in zebrafish.

Marine natural products

Covering: 2020This review covers the literature published in 2020 for marine natural products (MNPs), with 757 citations (747 for the period January to December 2020) 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 (1407 in 420 papers for 2020), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. A meta analysis of bioactivity data relating to new MNPs reported over the last five years is also presented.

Characterization and bioactivities of phospholipids from squid viscera and gonads using ultra-performance liquid chromatography-Q-exactive orbitrap/mass spectrometry-based lipidomics and zebrafish models

There has been great interest in phospholipids (PLs) from marine by-products due to their long-chain polyunsaturated fatty acids with unique health and functional properties. Here, marine PLs from squid viscera and gonads were comprehensively characterized and compared by UPLC-Q-Exactive Orbitrap/MS-based lipidomics analysis. A total of thirteen phospholipid classes including 1223 molecular species were identified and quantified in both resources. PC, PE and SM were further isolated from the total PLs of squid viscera and gonads, respectively. All isolated squid PL components were first evaluated for anti-inflammatory, antioxidant and cardiovascular effects using in vivo zebrafish models. Our results showed the diversity, content and physiological functions of PLs from squid by-products, which provided a basis for their future application in the nutritional and pharmaceutical industry.

Marine Alkaloids: Compounds with In Vivo Activity and Chemical Synthesis

Marine alkaloids comprise a class of compounds with several nitrogenated structures that can be explored as potential natural bioactive compounds. The scientific interest in these compounds has been increasing in the last decades, and many studies have been published elucidating their chemical structure and biological effects in vitro. Following this trend, the number of in vivo studies reporting the health-related properties of marine alkaloids has been increasing and providing more information about the effects in complex organisms. Experiments with animals, especially mice and zebrafish, are revealing the potential health benefits against cancer development, cardiovascular diseases, seizures, Alzheimer's disease, mental health disorders, inflammatory diseases, osteoporosis, cystic fibrosis, oxidative stress, human parasites, and microbial infections in vivo. Although major efforts are still necessary to increase the knowledge, especially about the translation value of the information obtained from in vivo experiments to clinical trials, marine alkaloids are promising candidates for further experiments in drug development.

An Integrated Strategy for Rapid Discovery and Identification of Quality Markers in Gardenia Fructus Using an Omics Discrimination-Grey Correlation-Biological Verification Method

Background: Gardenia Fructus (GF), a traditional Chinese medicine of Gardenia Ellis in Rubiaceae family, has the potential to clear heat and purge fire and has been widely used to treat multiple infection-related diseases. However, the quality markers (Q-Markers) of GF have not been revealed comprehensively.

Methods: In this experiment, the transgenic zebrafish lines, Tg (l-fabp:EGFP) and Tg (lyz:EGFP), were used to evaluate two main kinds of traditional efficacies of GF, hepatoprotective and anti-inflammatory effects. All the GF samples from different production areas were tested their anti-liver injury and anti-inflammantory activities. High-performance liquid chromatography-quadrupole time-of-flight mass spectrometry method (HPLC-Q-TOF/MS) was employed for herbal metabonomic analysis of GF samples. Gray correlation analysis (GCA) was utilized to screen out the components closely associated with the activities. Finally, the zebrafish model was applied to verify the bioactivity of the crucial components to determine the Q-Markers of GF.

Results: The zebrafish models were established by inducing with hydrogen peroxide or copper sulfate and applied to quickly evaluate the hepatoprotective effect and inflammation of GF samples. 27 potentially active components for liver protection and 21 potentially active components with anti-inflammatory properties were identified by herbal metabolomic analysis based on HPLC-Q-TOF/MS. The GCA result showed that five of the 27 components were highly correlated with liver protection, 15 of the 21 components were highly correlated with anti-inflammatory activity. Among them, geniposide and crocin-1 were confirmed their bioactivities on zebrafish experiment to be responsible for the protective effects of GF against liver injury, and genipin-1-β-D-gentiobioside, quinic acid, gardenoside, d-glucuronic acid, l-malic acid, mannitol, rutin, and chlorogenic acid were confirmed to be responsible for the anti-inflammatory effects. Finally, according to the screening principles of Q-Markers, genipin-1-β-D-gentiobioside, geniposide, and gardenoside were preliminarily identified to be the Q-Markers of GF.

Conclusion: This study established an effective research strategy of “Omics Discrimination-Grey Correlation-Biological Verification,” which enabled the rapid identification of key pharmacological components of GF. These markers have provided a scientific basis for constructing a modern quality evaluation system for GF.

New Prenylated Indole Homodimeric and Pteridine Alkaloids from the Marine-Derived Fungus Aspergillus austroafricanus Y32-2

Chemical investigation of secondary metabolites from the marine-derived fungus Aspergillus austroafricanus Y32-2 resulted in the isolation of two new prenylated indole alkaloid homodimers, di-6-hydroxydeoxybrevianamide E (1) and dinotoamide J (2), one new pteridine alkaloid asperpteridinate A (3), with eleven known compounds (4-14). Their structures were elucidated by various spectroscopic methods including HRESIMS and NMR, while their absolute configurations were determined by ECD calculations. Each compound was evaluated for pro-angiogenic, anti-inflammatory effects in zebrafish models and cytotoxicity for HepG2 human liver carcinoma cells. As a result, compounds 2, 4, 5, 7, 10 exhibited pro-angiogenic activity in a PTK787-induced vascular injury zebrafish model in a dose-dependent manner, compounds 7, 8, 10, 11 displayed anti-inflammatory activity in a CuSO₄-induced zebrafish inflammation model, and compound 6 showed significant cytotoxicity against HepG2 cells with an IC₅₀ value of 30 µg/mL.

Natural Nitrogenous Sesquiterpenoids and Their Bioactivity: A Review

Nitrogenous sesquiterpenoids fromnatural sourcesare rare, so unsurprisingly neither the potentially valuable bioactivity nor thebroad structural diversity of nitrogenous sesquiterpenoids has been reviewed before. This report covers the progressduring the decade from 2010 to February 2020 on the isolation, identification, and bioactivity of 391 nitrogen-containing natural sesquiterpenes from terrestrial plant, marine organisms, and microorganisms. This complete and in-depth reviewshouldbe helpful for discovering and developing new drugs of medicinal valuerelated to natural nitrogenous sesquiterpenoids.