315203-99-7Relevant academic research and scientific papers
Synthesis of the KLMN fragment of gymnocin-A using oxiranyl anion convergent methodology
Sakai, Takeo,Asano, Haruka,Furukawa, Kyoko,Oshima, Rie,Mori, Yuji
supporting information, p. 2268 - 2271 (2014/05/06)
Synthesis of the KLMN fragment of gymnocin-A has been achieved by a [X + 2 + Y]-type convergent strategy involving the coupling of a K-ring triflate and an N-ring epoxy sulfone. Fusions of the L ring and the M ring were carried out by intramolecular Ssub
Stereoselective 6-exo radical cyclization using cis-Vinyl sulfoxide: Practical total synthesis of CTX3C
Yamashita, Shuji,Ishihara, Yuuki,Morita, Hiroyuki,Uchiyama, Junichi,Takeuchi, Katsutoshi,Inoue, Masayuki,Hirama, Masahiro
, p. 357 - 364 (2011/05/13)
Ciguatoxins, the principal causative toxins of ciguatera seafood poisoning, are large ladder-like polycyclic ethers. We report a highly stereoselective 6-exo radical cyclization/ring-closing olefin metathesis sequence to construct the syn/trans-fused poly
Design and synthesis of ladder-shaped tetracyclic, heptacyclic, and decacyclic ethers and evaluation of the interaction with transmembrane proteins
Torikai, Kohei,Oishi, Tohru,Ujihara, Satoru,Matsumori, Nobuaki,Konoki, Keiichi,Murata, Michio,Aimoto, Saburo
supporting information; experimental part, p. 10217 - 10226 (2009/02/04)
Ladder-shaped polyether (LSP) toxins represented by brevetoxins and Ciguatoxins are thought to bind to transmembrane (TM) proteins. To elucidate the interactions of LSPs with TM proteins, we have synthesized artificial ladder-shaped polyethers (ALPs) containing 6/7/6/6 tetracyclic, 6/7/6/6/7/6/6 heptacyclic, and 6/7/6/6/7/6/6/7/6/6 decacyclic systems, based on the convergent method via α-cyano ethers. The ALPs possessing the simple iterative structure with different numbers of rings would be useful for structure-activity relationship studies on the molecular length, which is supposed to be important when naturally occurring LSPs elicit their toxicity. Two series of ALPs were prepared to evaluate the hydrophilic or hydrophobic effects of the side chains: (i) both sides were functionalized as diols (A series), and (ii) one side remained as diol and the other side was protected as benzyl ethers (B series). To examine the interaction of these ALPs with TM proteins, dissociation of glycophorin A (GpA) dimers into monomers was evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The heptacyclic ether (ALP7B) elicited the most potent activity in the presence of 2% SDS buffer, whereas the decacyclic ether (ALP10A) exhibited an intriguing phenomenon to induce precipitation of GpA in a dose-dependent manner, under the low concentration of SDS (0.03%). ALP10A also induced precipitation of integrin α 1β1, a TM protein known to form heterodimers in the lipid bilayer membranes. The different activities among the ALPs can be accounted for by the concept of hydrophobic matching that is, lengths of the hydrophobic region including the side chains of ALP7B and ALP10A are ca. 25 A, which match the lengths of the hydrophobic region of α-helical TM proteins, as well as the hydrophobic thickness of lipid bilayer membranes. The concept of the hydrophobic matching would be a clue to understanding the interaction between LSPs and TM proteins, and also a guiding principle to design ALPs possessing potent affinities with TM proteins.
Convergent Synthesis of the ABCDEF-Ring System of Yessotoxin and Adriatoxin
Suzuki, Keisuke,Nakata, Tadashi
, p. 3943 - 3946 (2007/10/03)
(Matrix Presented) The convergent synthesis of the ABCDEF-ring system of yessotoxin and adriatoxin was accomplished. This efficient convergent strategy was performed on the basis of the coupling of the acetylide of the A-ring and the triflate of the DEF-r
Synthetic studies on a marine polyether toxin, gambierol: Stereoselective synthesis of the EFGH ring system via B-alkyl Suzuki coupling
Fuwa, Haruhiko,Sasaki, Makoto,Tachibana, Kazuo
, p. 3019 - 3033 (2007/10/03)
A synthetic route to the EFGH ring system (3) of gambierol (1), a marine polyether toxin isolated from the dinoflagellate Gambierdiscus toxicus, has been developed. The present synthesis features convergent coupling of the F and H rings followed by ring-closure of the G ring based on the B-alkyl Suzuki reaction of lactone-derived enol phosphates. An angular methyl group at C23 was stereoselectively introduced by treatment of sulfone 32 with trimethylaluminum. Installation of a tertiary alcohol at C21 was accomplished through stereoselcetive dihydroxylation of exo-methylene 36 followed by selective formation of the primary p-toluensulfonate and treatment of the resultant monotosylate 40 with lithium aluminum hydride. Finally, formation of the E ring as a lactone form completed the synthesis of 3.
Synthetic studies on a marine polyether toxin, gambierol: Stereoselective synthesis of the FGH ring system via B-alkyl Suzuki coupling
Fuwa,Sasaki,Tachibana
, p. 8371 - 8375 (2007/10/03)
A synthetic route to the FGH ring system of gambierol, a marine polyether toxin isolated from the dinoflagellate Gambierdiscus toxicus, has been developed. The present synthesis features B-alkyl Suzuki coupling of the F and H rings, followed by ring-closure of the G ring and stereoselective installation of 1,3-diaxial methyl groups at C21 and C23. (C) 2000 Elsevier Science Ltd.
