Characterization and anti-inflammatory effects of iodinated acetylenic acids isolated from the marine sponges Suberites mammilaris and Suberites japonicus

Two New Pairs of Enantiomeric Butenolides from the Marine Sponge Suberties sp

Two new pairs of enantiomeric butenolides, (+)- and (-)-suberiteslide A, (+)- and (-)-subertieslide B had been obtained from the marine sponge Suberties sp. The structures with absolute configurations of these compounds were unequivocally determined by spectroscopic analyses and ECD (Electronic Circular Dichroism) method. It was the first separation of butenolides from the marine sponges of genus Suberites. Additionally, the anti-inflammatory, antibacterial and cytotoxic activities of these compounds were evaluated. The result indicated that only (-)-subertieslide B showed weak anti-inflammatory activity with the IC50 value of 40.8 μM.

Naturally Occurring Organohalogen Compounds-A Comprehensive Review

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

3D-printed hydroxyapatite scaffolds for bone tissue engineering: A systematic review in experimental animal studies

The use of 3D-printed hydroxyapatite (HA) scaffolds for stimulating bone healing has been increasing over the years. Although all the promising effects of these scaffolds, there are still few studies and limited understanding of their interaction with bone tissue and their effects on the process of fracture healing. In this context, this study aimed to perform a systematic literature review examining the effects of different 3D-printed HA scaffolds in bone healing. The search was made according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) orientations and Medical Subject Headings (MeSH) descriptors "3D printing," "bone," "HA," "repair," and "in vivo." Thirty-six articles were retrieved from PubMed and Scopus databases. After eligibility analyses, 20 papers were included (covering the period of 2016 and 2021). Results demonstrated that all the studies included in this review showed positive outcomes, indicating the efficacy of scaffolds treated groups in the in vivo experiments for promoting bone healing in different animal models. In conclusion, 3D-printed HA scaffolds are excellent candidates as bone grafts due to their bioactivity and good bone interaction.

Cytotoxic Bromine- and Iodine-Containing Cytochalasins Produced by the Mangrove Endophytic Fungus Phomopsis sp. QYM-13 Using the OSMAC Approach

Twelve new cytochalasins, phomopchalasins D-O (1-3, 5-12, and 14), including one brominated (2) and two iodinated cytochalasins (3 and 6), together with six known analogues (4, 13, and 15-18) were isolated from the mangrove-derived fungus Phomopsis sp. QYM-13 treated with 3% NaBr or 3% KI in potato liquid medium. Their structures and absolute configurations were established by extensive spectroscopic analysis (1D and 2D NMR, HRESIMS), electronic circular dichroism calculations, and a single-crystal X-ray diffraction experiment. Compounds 3 and 6 represent the first iodinated cytochalasins. Compounds 2, 15, 17, and 18 exhibited significant cytotoxicity against human cancer cell line MDA-MB-435 with IC₅₀ values ranging from 0.2 to 8.2 μM.

Synthesis of a novel brominated vinylic fatty acid with antileishmanial activity that effectively inhibits the Leishmania topoisomerase IB enzyme mediated by halogen bond formation

Many marine derived fatty acids, mainly from sponges, possess vinylic halogenated moieties (bromine or iodine) but their assessment as antileishmanial candidates remains elusive. In this work, we undertook the first total synthesis of a novel series of 2-allyl-3-halo-2-nonadecenoic acids, which preferentially inhibit the Leishmania DNA topoisomerase IB enzyme (LTopIB) over the human topoisomerase IB enzyme (hTopIB). The synthesis of 2-allyl-3-bromo-2E-nonadecenoic acid (1a) and 2-allyl-3-chloro-2E-nonadecenoic acid (2a) was achieved through a palladium catalyzed haloallylation of 2-nonadecynoic acid (2-NDA) using either allyl bromide or allyl chloride in the presence of PdCl2(PhCN)2 in 57–83 % overall yields. Among the new halogenated synthetic compounds, 1a was the most inhibitory of LTopIB with an EC50 = 7 μM, while the shorter chain analogs 2-allyl-3-bromo-2E-dodecenoic acid (1b) and 2-allyl-3-chloro-2E-dodecenoic acid (2b), synthesized from 2-dodecynoic acid, were not inhibitory of LTopIB (EC50 > 100 μM) resulting in the overall order of inhibition 1a > 2-NDA > 2a > > 1b ≅ 2b. The acids 1a and 2a inhibit LTopIB by a Gimatecan-independent mechanism. The enhanced LTopIB inhibition of 1a was computationally rationalized in terms of a halogen bond between the bromine in 1a and a DNA phosphate (binding energy = − 4.85 kcal/mol). Acid 1a also displayed preferential cytotoxicity towards Leishmania infantum amastigotes (EC50 = 2.5 μM) over L. infantum promastigotes (EC50 > 25 μM).

In Search of Alternative Antibiotic Drugs: Quorum-Quenching Activity in Sponges and their Bacterial Isolates

Owing to the extensive development of drug resistance in pathogens against the available antibiotic arsenal, antimicrobial resistance is now an emerging major threat to public healthcare. Anti-virulence drugs are a new type of therapeutic agent aiming at virulence factors rather than killing the pathogen, thus providing less selective pressure for evolution of resistance. One promising example of this therapeutic concept targets bacterial quorum sensing (QS), because QS controls many virulence factors responsible for bacterial infections. Marine sponges and their associated bacteria are considered a still untapped source for unique chemical leads with a wide range of biological activities. In the present study, we screened extracts of 14 sponge species collected from the Red and Mediterranean Sea for their quorum-quenching (QQ) potential. Half of the species showed QQ activity in at least 2 out of 3 replicates. Six out of the 14 species were selected for bacteria isolation, to test for QQ activity also in isolates, which, once cultured, represent an unlimited source of compounds. We show that ≈20% of the isolates showed QQ activity based on a Chromobacterium violaceum CV026 screen, and that the presence or absence of QQ activity in a sponge extract did not correlate with the abundance of isolates with the same activity from the same sponge species. This can be explained by the unknown source of QQ compounds in sponge-holobionts (host or symbionts), and further by the possible non-symbiotic nature of bacteria isolated from sponges. The potential symbiotic nature of the isolates showing QQ activity was tested according to the distribution and abundance of taxonomically close bacterial Operational Taxonomic Units (OTUs) in a dataset including 97 sponge species and 178 environmental samples (i.e., seawater, freshwater, and marine sediments). Most isolates were found not to be enriched in sponges and may simply have been trapped in the filtration channels of the sponge at the time of collection. Our results highlight potential for QQ-bioactive lead molecules for anti-virulence therapy both from sponges and the bacteria isolated thereof, independently on the symbiotic nature of the latter.

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.

Biological Activity of Recently Discovered Halogenated Marine Natural Products

This review presents the biological activity-antibacterial, antifungal, anti-parasitic, antiviral, antitumor, antiinflammatory, antioxidant, and enzymatic activity-of halogenated marine natural products discovered in the past five years. Newly discovered examples that do not report biological activity are not included.

Placotylene A, an inhibitor of the receptor activator of nuclear factor-κB ligand-induced osteoclast differentiation, from a Korean sponge Placospongia sp

A new inhibitor, placotylene A (1), of the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation, and a regioisomer of placotylene A, placotylene B (2), were isolated from a Korean marine sponge Placospongia sp. The chemical structures of placotylenes A and B were elucidated on the basis of 1D and 2D NMR, along with MS spectral analysis and revealed as an iodinated polyacetylene class of natural products. Placotylene A (1) displayed inhibitory activity against RANKL-induced osteoclast differentiation at 10 μM while placotylene B (2) did not show any significant activity up to 100 μM, respectively.

Naturally occurring organoiodines

This review, with 290 references, presents the fascinating area of iodinated natural products over the past hundred years for the first time.