New sesterterpene sulfates from the sponge Darwinella australensis

Marine Natural Products from Flora and Fauna of the Western Australian Coast: Taxonomy, Isolation and Biological Activity

Marine natural products occurring along the Western Australian coastline are the focus of this review. Western Australia covers one-third of the Australian coast, from tropical waters in the far north of the state to cooler temperate and Antarctic waters in the south. Over 40 years of research has resulted in the identification of a number of different types of secondary metabolites including terpenoids, alkaloids, polyketides, fatty acid derivatives, peptides and arsenic-containing natural products. Many of these compounds have been reported to display a variety of bioactivities. A description of the compound classes and their associated bioactivities from marine organisms found along the Western Australian coastline is presented.

A Soft Spot for Chemistry-Current Taxonomic and Evolutionary Implications of Sponge Secondary Metabolite Distribution

Marine sponges are the most prolific marine sources for discovery of novel bioactive compounds. Sponge secondary metabolites are sought-after for their potential in pharmaceutical applications, and in the past, they were also used as taxonomic markers alongside the difficult and homoplasy-prone sponge morphology for species delineation (chemotaxonomy). The understanding of phylogenetic distribution and distinctiveness of metabolites to sponge lineages is pivotal to reveal pathways and evolution of compound production in sponges. This benefits the discovery rate and yield of bioprospecting for novel marine natural products by identifying lineages with high potential of being new sources of valuable sponge compounds. In this review, we summarize the current biochemical data on sponges and compare the metabolite distribution against a sponge phylogeny. We assess compound specificity to lineages, potential convergences, and suitability as diagnostic phylogenetic markers. Our study finds compound distribution corroborating current (molecular) phylogenetic hypotheses, which include yet unaccepted polyphyly of several demosponge orders and families. Likewise, several compounds and compound groups display a high degree of lineage specificity, which suggests homologous biosynthetic pathways among their taxa, which identifies yet unstudied species of this lineage as promising bioprospecting targets.

Two novel bioactive sulfated guaiane sesquiterpenoid salt alkaloids from the aerial parts of Scorzonera divaricata

Extracts of the aerial parts of Scorzonera divaricata afforded sulfoscorzonin D (1) and sulfoscorzonin E (2), two novel pyrrolidine inner salt alkaloids with a sulfated guaiane sesquiterpene lactone nucleus, along with 22 known compounds. Especially, sulfoscorzonin D containing a unusual monoterpene moiety is very rare. The structures of new compounds were established using spectroscopic analysis including one- and two-dimensional NMR and HRESIMS. The cytotoxicities of compounds 1-4 and 10 against three tumor cell lines (K562, Hela, and HepG2) were evaluated using the MTT assay. Compounds 2 and 10 exhibited moderate cytotoxic activity. The biological properties of 1-3, 5-8, 10-14, and 16-24, were screened against nine different gram-positive and gram-negative bacteria. Compounds 1, 5-8, 10, and 18, showed potent antibacterial activities.

CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE

Glucozaluzanin C (PubChem CID: 442320); 1β,4α-dihydroxy-5α,6β,7α,11βH-eudermn-12; 6-olide (CID: 11119093); oleanolic acid (CID: 10494); lup-20(29)-ene-3β,28-diol (CID: 72326); (22E)-5α,8α-epidioxyergosta-6,22-dien-3β-ol (CID: 5469431); ergosta-3β,5α, 6β-trialcohol (CID: 44558918); stigma-5-en-3-O-β-glucoside (CID: 5742590); vomifoliol (CID: 12444927); trans-caffeic acid (CID: 689043); trans-p-hydroxy coumaric acid (CID: 637542); 4-hydroxy-3-methoxyphenyl ferulate (CID: 11500646); 7,3',4'-trihydroxyflavonol (CID: 5281614); tricin (ID: 5281702); luteolin (CID: 5280445); diosmetin (CID: 5281612); 5,7-dihydroxy-8-methoxyflavone (CID: 5281703); 5,7-dihydroxy-6-methoxyflavone (CID: 5320315); methyl-3,4-dihydroxy benzoate (CID: 287064); m-hydroxy benzoic acid (CID: 7420); 7-hydroxy-coumarin (CID: 5281426); and scopoletin (CID: 5280460).

Sesquiterpene lactones from Scorzonera austriaca

Six new sesquiterpene lactones, scorzoaustriacoside (1), scorzoaustriacin (2), scorzoaustriacin 3-O-beta-d-glucoside (3), 4-epi-dihydroestafiatol (4), 14-isovaleroxyscorzoaustricin (5), and 14-isovaleroxyscorzoaustricin sulfate (6), along with five known guaianolides, were isolated from an acetone extract of the roots of Scorzonera austriaca. The structures of the new compounds were elucidated mainly by interpretation of their 1D and 2D NMR and HRMS data. Several isolates obtained in this investigation were evaluated against a small panel of cancer cell lines.

Bioactive sulfated sesterterpene alkaloids and sesterterpene sulfates from the marine sponge Fasciospongia sp

Two new sulfated sesterterpene alkaloids, 19-oxofasciospongine A (3) and fasciospongine C (4), and a new sesterterpene sulfate, 25-hydroxyhalisulfate 9 (5), along with two known sesterterpene sulfates, halisulfates 7 (6) and 9 (7), were isolated from an organic extract of the marine sponge Fasciospongia sp. The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectroscopic studies as well as by HRESIMS analysis. Compounds 1-7 exhibited inhibitory activity against Streptomyces 85E in the hyphae-formation inhibition assay. Compounds 1, 2, and 4-7 were not cytotoxic when tested at 20 microg/mL with MCF-7, LNCaP, and LU cell lines. Only compound 3 demonstrated a moderate cytotoxic effect on the MCF-7 (IC(50) 13.4 microM), LNCaP (IC(50) 21.8 microM), and LU-1 cells (IC(50) 5.0 microM), respectively.

Inhibition of Candida albicans isocitrate lyase activity by sesterterpene sulfates from the tropical sponge Dysidea sp

Seven sesterterpene sulfates (1-7) were isolated from the tropical sponge Dysidea sp. and their inhibitory activities against isocitrate lyase (ICL) from Candida albicans were evaluated. Among the isolated natural products compound 6 and 7 were found to be strong ICL inhibitors. The isolated compounds (1-7) also showed potent antibacterial effect against Bacillus subtilis and Proteus vulgaris, but did not display antifungal activity.

Protein phosphatase inhibitors isolated from Spongia irregularis collected in Papua New Guinea

Irregularasulfate (1), a new nitrogen-containing sesterterpenoid, and the known sesterterpenoids hipposulfate C (2), halisulfate-7 (3), and igernellin (4), have been isolated from the marine sponge Spongia irregularis collected in Papua New Guinea. The structure of 1 was elucidated via analysis of its spectroscopic data. Sesterterpenoids 1, 2, and 3 are moderate inhibitors of the catalytic subunits of the mammalian Ser/Thr protein phosphatases calcineurin, PP-1, and PP-2A. The phosphate analogue of 3 and the thiophosphate analogue of 2 have been prepared from the corresponding natural products and evaluated for their ability to inhibit the phosphatase activity of calcineurin.

Novel Sulfated Sesterterpene Alkaloids from the Marine Sponge Fasciospongia sp

Fasciospongines A (1) and B (2), two unusual sulfated sesterterpene alkaloids of an unprecedented structural class, have been isolated from the marine sponge Fasciospongia sp. The structures were elucidated on the basis of spectroscopic analysis. Compounds 1 and 2 displayed potent inhibitory activity to Streptomyces 85E in the hypha formation inhibition (HFI) bioassay.

Status and perspective of sponge chemosystematics

In addition to their pharmaceutical applications, sponges are an important source of compounds that are used to elucidate classification patterns and phylogenetic relationships. Here we present a review and outlook on chemosystematics in sponges in seven sections: Secondary metabolites in sponges; Further applications of bioactive compound research in sponges; Sponge chemotaxonomy; Pitfalls of sponge chemotaxonomy; The chemotaxonomic suitability of sponge compounds; Potential synapomorphic markers in sponges; and The future of sponge chemotaxonomy.

Rhizochalin A, a novel two-headed sphingolipid from the sponge Rhizochalina incrustata

Rhizochalin A (4), the fourth representative of two-headed glycosphingolipids, was isolated as its peracetate from the sponge Rhizochalina incrustata. Its structure has been established as the 2-ethyl carbamoate of rhizochalin on the basis of spectroscopic data and chemical transformations.

Marine natural products

This review covers the literature published in 2003 for marine natural products, with 619 citations (413 for the period January to December 2003) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (656 for 2003), together with their relevant biological activities, source organisms and country or origin. Biosynthetic studies or syntheses that lead to the revision of structures or stereochemistries have been included (78), including any first total syntheses of a marine natural product.