https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Covering: 2010. Previous review: Nat. Prod. Rep., 2011, 28, 196. This review covers the literature published in 2010 for marine natural products, with 895 citations (590 for the period January to December 2010) 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 (1003 for 2010), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

Review: Marine natural products

The potential of mangrove-derived endophytic fungi as a promising source of diverse and structurally unprecedented bioactive natural products is unquestionable and continues to attract considerable attention. This review highlights new bioactive mangrove fungal metabolites and known compounds with hitherto unreported biological activities described during the last 10 years. The compounds are categorized according to their reported biological activities, including cytotoxic, anti-infective, in addition to a wide range of miscellaneous activities such as protein kinase, α-glucosidase, acetylcholinesterase and tyrosinase inhibitory activities, as well as antiangiogenic and neovascularisation effects, radical scavenging, DNA-binding affinity, and calcium and potassium channel blocking activity.

Mangrove derived fungal endophytes – a chemical and biological perception

This review summarizes new findings concerning the sources and characteristics of various natural products that can be extracted from mangrove-associated microbes over the past three years (January 2011–December 2013). The natural products are discussed with a focus on bioactivity, highlighting the unique chemical diversity of these metabolic products.

Bioactive natural products derived from mangrove-associated microbes

The skin is chronically exposed to endogenous and environmental pro-oxidant agents, leading to the harmful generation of reactive oxygen species. Antioxidant is vital substances which possess the ability to protect the body from damage cause by free radicals induce oxidative stress. Alpinia zerumbet, a traditionally important economic plant in Okinawa, contains several interesting bioactive constituents and possesses health promoting properties. In this regard, we carried out to test the inhibitory effect of crude extracts and isolated compounds from A. zerumbet on antioxidant and skin diseases-related enzymes. The antioxidant activities were examined by DPPH, ABTS and PMS-NADH radical scavenging. Collagenase, elastase, hyaluronidase and tyrosinase were designed for enzymatic activities to investigate the inhibitory properties of test samples using a continuous spectrophotometric assay. The inhibitory capacity of test samples was presented at half maximal inhibitory concentration (IC50). The results showed that aqueous extract of the rhizome was found to have greater inhibitory effects than the others on both of antioxidant and skin diseases-related enzymes. Furthermore, 5,6-dehydrokawain (DK), dihydro-5,6-dehydrokawain (DDK) and 8(17),12-labdadiene-15,16-dial (labdadiene), isolated from rhizome, were tested for antioxidant and enzyme inhibitions. We found that DK showed higher inhibitory activities on DPPH, ABTS and PMS-NADH scavenging (IC50 = 122.14 ± 1.40, 110.08 ± 3.34 and 127.78 ± 4.75 μg/ml, respectively). It also had stronger inhibitory activities against collagenase, elastase, hyaluronidase and tyrosinase (IC50 = 24.93 ± 0.97, 19.41 ± 0.61, 19.48 ± 0.24 and 76.67 ± 0.50 μg/ml, respectively) than DDK and labdadiene. Our results indicate that the rhizome aqueous extract proved to be the source of bioactive compounds against enzymes responsible for causing skin diseases. Moreover, DK could be used as a potent inhibitor and be further exploited to be used in anti-skin disease formulations.

/pdf/effect-of-alpinia-zerumbet-components-on-antioxidant-and-54gc8pa4t4.pdf

Effect of Alpinia zerumbet components on antioxidant and skin diseases-related enzymes

Bioactive steroidal alkaloids from the fruits of Solanum nigrum.

Three new dimeric naphtho- γ-pyrones, named rubasperone A ( 1), rubasperone B ( 2), and rubasperone C ( 3), together with two known compounds, rubrofusarin ( 4) and rubrofusarin B ( 5), were isolated from the mangrove endophytic fungus ASPERGILLUS TUBINGENSIS (GX1-5E). Their structures were determined by spectroscopic methods, including IR, MS, and 1D and 2D NMR. The structures of 1 and 2 were further confirmed by X-ray crystallography. In the bioactivity assays against tyrosinase and α-glucosidase, rubrofusarin ( 4) exhibited moderate tyrosinase inhibitory activity, with an IC 50 value of 65.6 μM, and rubasperone C ( 3) showed mild α-glucosidase inhibitory activity, with an IC 50 value of 97.3 μM.

Three dimeric naphtho-γ-pyrones from the mangrove endophytic fungus Aspergillus tubingensis isolated from Pongamia pinnata.

Chemical investigation of the aerial parts of Xanthium sibiricum led to the isolation of four new xanthanolide-type sesquiterpene lactones, including two xanthanolide dimers, pungiolide D (1) and pungiolide E (2), and two xanthanolide monomers, 8-epi-xanthatin-1α,5α-epoxide (3) and 1β-hydroxyl-5α-chloro-8-epi-xanthatin (4), together with four known compounds, pungiolide A (5), 8-epi-xanthatin-1β,5β-epoxide (6), xanthatin (7), and 11α,13-dihydro-8-epi-xanthatin (8). The structures of these compounds were elucidated on the basis of spectroscopic data analysis. Pungiolide D (1) displayed an unusual structure featuring a 5/5/6-fused tricyclic system in the unit B. Compound 4 was shown to be a rare sesquiterpene lactone containing halogen, and its absolute configuration was determined by X-ray crystallographic analysis. The evaluation of the cytotoxic activities of the isolated new compounds against the SNU387 liver and A-549 lung human cancer cell lines showed that compound 4 possessed significant in vitro cytotoxicity with an IC50 value of 5.1 µM against SNU387 liver cells.

Cytotoxic Sesquiterpene Lactones from Aerial Parts of Xanthium sibiricum

Flavonoid glycosides and alkaloids from the embryos of Nelumbo nucifera seeds and their antioxidant activity.

Four new meroterpenoids, arnebinols A–D (1–4), and one new prenylated naphthoquinone, 5,8-O-dimethyl-11-deoxyalkannin (5), together with seven known meroterpenoids (6–12) were isolated from the roots of Arnebia euchroma. The structures of the isolated compounds were elucidated unambiguously by spectroscopic data analysis, as well as X-ray-single crystal diffraction analysis. Arnebinol A (1) and B (2) are rare meroterpenoids possessing a 6/10/5 tricyclic ring system. Compounds 1–12 were evaluated for their cytotoxicities against MG-63 and SNU387 human cancer cell lines. Compound 5 exhibited the most potent activity with IC50 values of 2.69 µM and 6.08 µM, respectively.

Bin Chen

Papers

Bioactive steroidal alkaloids from the fruits of Solanum nigrum.

Three dimeric naphtho-γ-pyrones from the mangrove endophytic fungus Aspergillus tubingensis isolated from Pongamia pinnata.

Cytotoxic Sesquiterpene Lactones from Aerial Parts of Xanthium sibiricum

Flavonoid glycosides and alkaloids from the embryos of Nelumbo nucifera seeds and their antioxidant activity.

Meroterpenoids and a naphthoquinone from Arnebia euchroma and their cytotoxic activity.