Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

• Kairi Umeda,
• Naoaki Kurisawa,
• Ghulam Jeelani,
• Tomoyoshi Nozaki,
• Kiyotake Suenaga and
• Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

• . Polycavernoside E (1) exhibited moderate antitrypanosomal activity against Trypanosoma brucei rhodesiense. Furthermore, the isolation of polycavernoside E (1) from marine cyanobacteria provides additional evidence that marine cyanobacteria, and not red algae, are responsible for the biosynthesis of

• polycavernosides. Keywords: macrolide glycoside; marine cyanobacterium; marine natural products; polycavernosides; terminal alkyne; Introduction In 1991, an outbreak of food poisoning caused by a species of red algae known as ‘Polycavernosa tsudai’ occurred in Guam, which resulted in killing of three people. Two

• novel macrolide glycosides, polycavernosides A (2) and B (3), were reported as the causative compounds for the illness [1]. After that, the second fatal food poisoning incidents occurred in the Philippines caused by the ingestion of polycavernoside A (2)-contaminated red algae [2]. Subsequently

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• viridis [14][15][16]. Only few terpene synthases have been characterised from other organisms, including enzymes from insects [17], octocorals [18][19], red algae [20][21], and amobae [22][23]. Despite these previous efforts, for many known terpenes still no terpene synthases catalysing their formation

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• :1). Additional transformation of compound 230 following an A–AB–ABC synthetic strategy resulted in the desired complex tricyclic skeleton opening the door for the total synthesis of 12-epi-JBIR-23/24 (Scheme 61). The sulfated β-glycoside peyssonnoside A was isolated only recently from the red algae

New sesquiterpenoids from the South China Sea soft corals Clavularia viridis and Lemnalia flava

• Qihao Wu,
• Yuan Gao,
• Meng-Meng Zhang,
• Li Sheng,
• Jia Li,
• Xu-Wen Li,
• Hong Wang and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2019, 15, 695–702, doi:10.3762/bjoc.15.64

• . viridis and L. flava. In fact, to our knowledge, naturally occurring laurane- (1–4) and cuparane-derived (5) sesquiterpenoids, are extremely rare in soft corals. Previously, such sesquiterpenoids have only been isolated from the red algae of the genus Laurencia [14][16][17][21] and some sea hares that

Herpetopanone, a diterpene from Herpetosiphon aurantiacus discovered by isotope labeling

• Xinli Pan,
• Nicole Domin,
• Sebastian Schieferdecker,
• Hirokazu Kage,
• Martin Roth and
• Markus Nett

Beilstein J. Org. Chem. 2017, 13, 2458–2465, doi:10.3762/bjoc.13.242

• , whereas a plant-derived sesquiterpene with this feature was already reported in 1965. Oplopanone (2, Figure 3) was originally isolated from Oplopanax japonicus [18][19], but can also be found in a number of other plants as well as red algae [20][21]. Comparison of the chemical shifts in 1 with published

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

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

• to employ outlying natural variants of RuBisCO that display the best properties, such as those from red algae, in combination with other components of the Calvin cycle carbon assimilation mechanism [39]. Long et al. [78] estimated that incorporation of wild-type enzymes, with higher CO2 specificity

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

• 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