Algal pheromone biosynthesis: stereochemical analysis and mechanistic implications in gametes of Ectocarpus siliculosus

Nitrogen-Containing Volatiles from Marine Salinispora pacifica and Roseobacter-Group Bacteria

Bacteria can produce a wide variety of volatile compounds. Many of these volatiles carry oxygen, while nitrogen-containing volatiles are less frequently observed. We report here on the identification and synthesis of new nitrogen-containing volatiles from Salinispora pacifica CNS863 and explore the occurrence in another bacterial lineage, exemplified by Roseobacter-group bacteria. Several compound classes not reported before from bacteria were identified, such as dialkyl ureas and oxalamides. Sulfinamides have not been reported before as natural products. The actinomycete S. pacifica CNS863 produces, for example, sulfinamides N-isobutyl- and N-isopentylmethanesulfinamide (5, 6), urea N,N'-diisobutylurea (16), and oxalamide N,N'-diisobutyloxalamide (17). In addition, new imines such as (E)-1-(furan-2-yl)-N-(2-methylbutyl)methanimine (8) and (E)-2-((isobutylimino)methyl)phenol (13) were identified together with several other imines, acetamides, and formamides. Some of these compounds including the sulfinamides were also released by the Roseobacter-group bacteria Roseovarius pelophilus G5II, Pseudoruegeria sp. SK021, and Phaeobacter gallaeciensis BS107, although generally fewer compounds were detected. These nitrogen-containing volatiles seem to originate from biogenic amines derived from the amino acids valine, leucine, and isoleucine.

Pheromone signaling during sexual reproduction in algae

Algae are found in all aquatic and many terrestrial habitats. They are dominant in phytoplankton and biofilms thereby contributing massively to global primary production. Since algae comprise photosynthetic representatives of the various protoctist groups their physiology and appearance is highly diverse. This diversity is also mirrored in their characteristic life cycles that exhibit various facets of ploidy and duration of the asexual phase as well as gamete morphology. Nevertheless, sexual reproduction in unicellular and colonial algae usually has as common motive that two specialized, sexually compatible haploid gametes establish physical contact and fuse. To guarantee mating success, processes during sexual reproduction are highly synchronized and regulated. This review focuses on sex pheromones of algae that play a key role in these processes. Especially, the diversity of sexual strategies as well as of the compounds involved are the focus of this contribution. Discoveries connected to algal pheromone chemistry shed light on the role of key evolutionary processes, including endosymbiotic events and lateral gene transfer, speciation and adaptation at all phylogenetic levels. But progress in this field might also in the future provide valid tools for the manipulation of aquaculture and environmental processes.

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.

Bioresolution of benzyl glycidyl ether using whole cells of Bacillus alcalophilus

The incubation of whole Bacillus alcalophilus cells grown on a mineral supplemented medium (MSM) containing 1% (w/v) sucrose as carbon source, 1.2% (w/v) tryptone as nitrogen source at pH 6.5 and temperature 30 °C in 24 h kinetically resolved benzyl glycidyl ether (1 mg/ml) to provide (S)-benzyl glycidyl ether with 30% ee and (R)-3-benzyloxypropane-1,2-diol with 40% ee.