The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• oxide (79) in a further few steps. Teurilene Teurilene (82) is a squalene-derived cytotoxic polyether which was originally extracted from the red algae Laurencia obtusa by Suzuki et al. [138][139]. Though it is CS-symmetric, it is structurally closely related to pentacyclic C2-symmetric glabrescol [140

• with 8% of its diastereoisomer 92b and a minor amount of the double cyclized product 92c. Both synthesized THF fragments were consistent with those reported by Kodama [156] (Scheme 19). Venustatriol The tetracyclic oxasqualenoid venustatriol (96) was isolated in 1986 by Sakemi et al. from the red algae

Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

• Frederick J. Seidl and
• Noah Z. Burns

Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129

• regio- and enantioselectivity. Disclosed herein, this discovery has enabled the first total synthesis of (−)-anverene (1) (Scheme 1, bottom), a secondary metabolite from the algae Plocamium cartilagineum with selective antibiotic activity against vancomycin-resistant Enterococcus faecium (VREF) [10

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• generation biofuel production processes. In this way, the carbon fixed by plants (biomass) is further transformed into a wide array of products through microbial processing [16]. Genetically engineered plants and algae have been employed to divert carbon flux in planta towards other metabolic products of

• C3 carbon fixation was thought to be the only important biological process for CO2 assimilation, as a result of its prevalence in our immediate environment. It is found in photosynthetic organisms, predominantly in plants on land and algae in water, and photosynthetic prokaryotes (cyanobacteria

• received much attention for application in biotechnology for CO2-fixation, particularly using engineered photosynthetic hosts, such as plants and algae. The inefficiency of RuBisCO and promiscuity towards oxygen have directed efforts in protein engineering towards the generation of optimised mutants that

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• different dienophiles followed by aromatization which gave the crownophanes (e.g., 148 and 151) (Scheme 22). Cross metathesis: In 1992, (−)-cylindrocyclophane A (156) and (−)-cylindrocyclophane F (155) were isolated by Moore and co-workers [143] from a blue-green algae belonging to Cylindrospermum

Synthesis and biological evaluation of novel N-α-haloacylated homoserine lactones as quorum sensing modulators

• Michail Syrpas,
• Ewout Ruysbergh,
• Christian V. Stevens,
• Norbert De Kimpe and
• Sven Mangelinckx

Beilstein J. Org. Chem. 2014, 10, 2539–2549, doi:10.3762/bjoc.10.265

• components of microorganisms, algae, marine invertebrates, and some plants and animals [20][21]. Interest in these naturally occurring products is high as they often exhibit fascinating biological activities [22][23][24]. Furthermore, due to the reactivity of halogen substituents, this novel class of

Relay cross metathesis reactions of vinylphosphonates

• Raj K. Malla,
• Jeremy N. Ridenour and
• Christopher D. Spilling

Beilstein J. Org. Chem. 2014, 10, 1933–1941, doi:10.3762/bjoc.10.201

• turmerone [4] and enterolactone [5], the phosphonate derivatives of the natural product cyclophostin [6], the C18–C34 fragment of amphidinolide C [7], and the oxylipids from Australian brown algae [8]. The potential of vinylphosphonates as intermediates in organic synthesis is limited by their chemistry

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• 16. Biosynthetic applications The DVCPR has been shown to be part of the biosynthesis of ectocarpene (21, see Scheme 4) [29], an inactivated algae pheromone [30][31]. Starting from all-cis-pentaenic acid (18) peroxidation is supposed to take place to give 19, followed by formation of the active algae

• measured half-life for the conversion from 20 to 21 was longer than the necessary time for sexual encounter of the algae cycloheptadiene 21 was ruled out as a time-dependent sexual pheromone [32]. A divinyloxirane rearrangement has been proposed as the key step in the biosynthesis of several natural

• sexual pheromone of brown algae (20). Proposed biosynthesis of occidenol (25) and related natural compounds. Gaich’s bioinspired system using the DVCPR to mimick the dimethylallyltryptophan synthase. DMAPP = dimethylallyl pyrophosphate. Iguchi’s total synthesis of clavubicyclone, part 1. Iguchi’s total

SF002-96-1, a new drimane sesquiterpene lactone from an Aspergillus species, inhibits survivin expression

• Silke Felix,
• Louis P. Sandjo,
• Till Opatz and
• Gerhard Erkel

Beilstein J. Org. Chem. 2013, 9, 2866–2876, doi:10.3762/bjoc.9.323

• promoter and subsequently triggering apoptosis in Colo 320 cells. Drimane sesquiterpenes are widespread in plants, fungi and marine organisms such as algae, sponges and corals and have attracted some attention for their potent antibacterial, antifungal, cytotoxic, antifeedant, phytotoxic, piscicidal and

Halogenated volatiles from the fungus Geniculosporium and the actinomycete Streptomyces chartreusis

• Tao Wang,
• Patrick Rabe,
• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2767–2777, doi:10.3762/bjoc.9.311

• [6], marinopyrrols [7][8], armeniaspirols [9], and salinosporamide [10]. Also a few volatile halogenated compounds are known, e.g., from algae as summarised in a recent review [11]. Particularly interesting is the production of chloroform by termites that was estimated to account for 15% of the

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

• Nelson L. Brock,
• Christian A. Citron,
• Claudia Zell,
• Martine Berger,
• Irene Wagner-Döbler,
• Jörn Petersen,
• Thorsten Brinkhoff,
• Meinhard Simon and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 942–950, doi:10.3762/bjoc.9.108

• clade within the class of alphaproteobacteria is found both in seawater and marine sediments and occurs often in association with marine algae [1]. Genome data from sequenced clade members revealed that pathways for the degradation of aromatic compounds and sulfur metabolic pathways are widespread [2

Algicidal lactones from the marine Roseobacter clade bacterium Ruegeria pomeroyi

• Ramona Riclea,
• Julia Gleitzmann,
• Hilke Bruns,
• Corina Junker,
• Barbara Schulz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2012, 8, 941–950, doi:10.3762/bjoc.8.106

• investigate their activity against several bacteria, fungi, and algae. A specific algicidal activity was observed that may be important in the interaction between the bacteria and their algal hosts in fading algal blooms. Keywords: bacteria-algae symbiosis; lactones; Roseobacter; synthesis; volatiles

• symbionts [3][4] or associated with molluscs [5]; and can form biofilms [6]. Particularly interesting from an ecological point of view is their association with marine algae, such as dinoflagellates and coccolithophores, which produce large amounts of the sulfur metabolite dimethylsulfoniopropionate (1

• an attractant for Ruegeria sp. TM1040 and causes flagella-mediated chemotactic behaviour [9], suggesting an important role of DMSP in the symbiosis between the algae and bacteria. Upon lysis of ageing blooms by viruses, or cell disruption by grazing, the intracellular DMSP is released, making the

Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

• Martin Rempt,
• Florian Weinberger,
• Katharina Grosser and
• Georg Pohnert

Beilstein J. Org. Chem. 2012, 8, 283–289, doi:10.3762/bjoc.8.30

• the herbivorous sea snail Echinolittorina peruviana. The chemical stress response of both species was monitored by LC–ESIMS-based metabolic profiling and revealed commonalities and differences. Both algae rely on a rapid lipoxygenase mediated transformation of arachidonic acid to known and novel

• artificial food containing the respective oxylipins. Both algae species are defended against this general herbivore by 7,8-dihydroxyeicosatetraenoic acid, whereas the prostaglandins and the novel oxylipins were inactive at naturally occurring concentrations. The role of different oxylipins in the invasive

• potential of Gracilaria spp. is discussed. Keywords: activated chemical defense; invasive species; oxylipins; prostaglandins; red algae; regulation; Introduction The red alga Gracilaria chilensis is native along the Chilean coast and is commercially farmed for the production of agar hydrocolloids [1

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

• Jan-Christoph Kehr,
• Douglas Gatte Picchi and
• Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

• sporulation. Beside microsporines that consist of a single amino acid linked to cyclohexenone, cyanobacteria and other algae produce mycosporine-like amino acids (MAAs, 20), which contain two substituents linked to the central ring by imine linkages. Four enzymes are involved in the synthesis of the specific

Toward an integrated route to the vernonia allenes and related sesquiterpenoids

• Da Xu,
• Michael A. Drahl and
• Lawrence J. Williams

Beilstein J. Org. Chem. 2011, 7, 937–943, doi:10.3762/bjoc.7.104

• terrestrial plants, algae, and insect pheromones that purportedly have anticancer, antifungal, and antibiotic activity, among others. For example, parthenolide (6) has anti-inflammatory and anti-hyperalgesic effects and induces apoptosis of human acute myelogenous leukemia stem and progenitor cells [24