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

Marine sponges belonging to the phylum Porifera (Metazoa), evolutionarily the oldest animals are the single best source of marine natural products. The present review presents a comprehensive overview of the source, taxonomy, country of origin or geographical position, chemical class, and biological activity of sponge-derived new natural products discovered between 2001 and 2010. The data has been analyzed with a view to gaining an outlook on the future trends and opportunities in the search for new compounds and their sources from marine sponges.

https://www.mdpi.com/1660-3397/12/8/4539/pdf

Marine sponge derived natural products between 2001 and 2010: trends and opportunities for discovery of bioactives.

Lignin, a phenolic polymer in the secondary wall, is the major cause of lignocellulosic biomass recalcitrance to efficient industrial processing. From an applications perspective, it is desirable that second-generation bioenergy crops have lignin that is readily degraded by chemical pretreatments but still fulfill its biological role in plants. Because plants can tolerate large variations in lignin composition, often without apparent adverse effects, substitution of some fraction of the traditional monolignols by alternative monomers through genetic engineering is a promising strategy to tailor lignin in bioenergy crops. However, successful engineering of lignin incorporating alternative monomers requires knowledge about phenolic metabolism in plants and about the coupling properties of these alternative monomers. Here, we review the current knowledge about lignin biosynthesis and the pathways towards the main phenolic classes. In addition, the minimal requirements are defined for molecules that, upon incorporation into the lignin polymer, make the latter more susceptible to biomass pretreatment. Numerous metabolites made by plants meet these requirements, and several have already been tested as monolignol substitutes in biomimetic systems. Finally, the status of detection and identification of compounds by phenolic profiling is discussed, as phenolic profiling serves in pathway elucidation and for the detection of incorporation of alternative lignin monomers.

/pdf/metabolic-engineering-of-novel-lignin-in-biomass-crops-4emnnx1bxv.pdf

Metabolic engineering of novel lignin in biomass crops

Natural products as a source of Alzheimer's drug leads

Sebestenoids A-D, BACE1 inhibitors from Cordia sebestena.

Eight pentacyclic compounds, xestosaprols F-M (1-8), were isolated from a marine sponge belonging to the genus Xestospongia. The structures of these new compounds were determined on the basis of extensive analyses of NMR experiments and mass spectrometric measurements. These compounds inhibited the aspartic protease BACE1 at moderate levels in a dose-dependent manner.

/pdf/xestosaprols-from-the-indonesian-marine-sponge-xestospongia-39ka19qgow.pdf

Xestosaprols from the Indonesian Marine Sponge Xestospongia sp.

Three isopropyl steroids, topsentinols K, L, and K trisulfate (1-3), were isolated from an undescribed species of Topsentia. The structures of the new compounds were determined by extensive 1D and 2D NMR experiments and mass spectrometry measurements. Topsentinol K trisulfate (3) inhibited the aspartic protease BACE1, although in a detergent-dependent manner suggestive of nonspecific aggregation.

Topsentinols, 24-Isopropyl Steroids from the Marine Sponge Topsentia sp.

Despite the long history of drug discovery from natural sources, the marine environment, which covers 70% of the Earths surface, is still relatively unexplored. Intense competition for limited resources drives the evolution of specific and potent chemical defenses distinct from their terrestrial counterparts. Based on this rationale, we recently began screening extracts derived from marine invertebrate and cyanobacterial samples for BACE-1 inhibitors in a chemiluminescent enzyme-fragment complementation (EFC) assay. The results of this broad screening are presented here, along with our progress towards the development of a secondary LC-MS homogeneous affinity assay. Incubation of the extracts active in the EFC assay with BACE1, subsequent isolation of the enzyme-inhibitor complex and then analysis of the small molecule inhibitor by LC-MS rapidly links a chemical structure to biological activity. This approach enables the rapid targetorientated discovery of BACE-1 inhibitors from marine sources.

/pdf/new-methods-to-explore-marine-resources-for-alzheimer-s-oycnb57efc.pdf

Analia Sorribas

Papers

Natural products as a source of Alzheimer's drug leads

Sebestenoids A-D, BACE1 inhibitors from Cordia sebestena.

Xestosaprols from the Indonesian Marine Sponge Xestospongia sp.

Topsentinols, 24-Isopropyl Steroids from the Marine Sponge Topsentia sp.

New methods to explore marine resources for Alzheimer's therapeutics.