Browse
Submit Data
Databases
API
Help

Dataset Information

14 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Total synthesis of the proposed structure of astakolactin.

ABSTRACT: The first total synthesis of the proposed structure of astakolactin, a sesterterpene metabolite isolated from the marine sponge Cacospongia scalaris, has been achieved, mainly featuring Johnson-Claisen rearrangement, asymmetric Mukaiyama aldol reaction and MNBA-mediated lactonization.

SUBMITTER: Tonoi T

PROVIDER: S-EPMC4222296 | biostudies-other | 2014

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Total synthesis of the proposed structure of astakolactin.

Tonoi Takayuki T Mameda Keisuke K Fujishiro Moe M Yoshinaga Yutaka Y Shiina Isamu I

Beilstein journal of organic chemistry 20141017

The first total synthesis of the proposed structure of astakolactin, a sesterterpene metabolite isolated from the marine sponge Cacospongia scalaris, has been achieved, mainly featuring Johnson-Claisen rearrangement, asymmetric Mukaiyama aldol reaction and MNBA-mediated lactonization. ...[more]

PMID: 25383112

Similar Datasets

Total synthesis of the proposed structure of briarellin J.

Project description:The total synthesis of the originally proposed structure of briarellin J is reported in 15 steps from a known compound and in 23 steps from readily available materials. Key reactions include an exo-selective intramolecular Diels-Alder and a substrate-controlled hydroboration. Discrepancies in the spectroscopic data of the synthetic and natural material led to a revision of the assigned structure.

| S-EPMC2966518 | biostudies-literature

Total Synthesis of the Proposed Structure of Paraphaeosphaeride C.

Project description:Paraphaeosphaeride C is a demethoxy derivative of phaeosphaeride A and exhibits STAT3 inhibitory activity. Our previous papers reported the total synthesis of phaeosphaeride A using a diastereoselective vinyl anion aldol reaction as the key step to construct the dihydropyran ring. In this work, the first total synthesis of the proposed structure of paraphaeosphaeride C was achieved via a similar synthetic strategy. The synthetic compound was characterized through extensive nuclear magnetic resonance (NMR) analysis but the 1H and 13C-NMR data for this compound did not correspond to those reported in the literature for paraphaeosphaeride C.

| S-EPMC6930451 | biostudies-literature

Total Synthesis Confirms the Molecular Structure Proposed for Oxidized Levuglandin D2.

Project description:Levuglandins (LG)D2 and LGE2 are ?-ketoaldehyde levulinaldehyde derivatives with prostanoid side chains produced by spontaneous rearrangement of the endoperoxide intermediate PGH2 in the biosynthesis of prostaglandins. Covalent adduction of LGs with the amyloid peptide A?1-42 promotes formation of the type of oligomers that have been associated with neurotoxicity and are a pathologic hallmark of Alzheimer's disease. Within 1 min of their generation during the production of PGH2 by cyclooxygenation of arachidonic acid, LGs are sequestered by covalent adduction to proteins. In view of this high proclivity for covalent adduction, it is understandable that free LGs have never been detected in vivo. Recently a catabolite, believed to be an oxidized derivative of LGD2 (ox-LGD2), a levulinic acid hydroxylactone with prostanoid side chains, was isolated from the red alga Gracilaria edulis and detected in mouse tissues and in the lysate of phorbol-12-myristate-13-acetate-treated THP-1 cells incubated with arachidonic acid. Such oxidative catabolism of LGD2 is remarkable because it must be outstandingly efficient to prevail over adduction with proteins and because it requires a unique dehydrogenation. We now report a concise total synthesis that confirms the molecular structure proposed for ox-LGD2. The synthesis also produces ox-LGE2, which readily undergoes allylic rearrangement to ?6-ox-LGE2.

| S-EPMC6013286 | biostudies-literature

Total synthesis of the putative structure of the proposed Banyasin A.

Project description:The first total synthesis of four possible isomers of a molecule possessing the configuration proposed for Banyasin A is described. The structure synthesized appears to be different from that of the natural product.

| S-EPMC4362330 | biostudies-literature

Evolution of a strategy for the synthesis of structurally complex batzelladine alkaloids. Enantioselective total synthesis of the proposed structure of batzelladine F and structural revision.

Project description:Stereoselective synthesis of octahydro-5,6,6a-triazaacenaphthalenes 29 and 34 having the anti-relationship of the angular hydrogens flanking the pyrrolidine nitrogen confirmed suspicions that the relative configuration of the left-hand tricyclic guanidine fragment of batzelladine F should be revised to have the syn relationship of these hydrogens. Several strategies were examined for coupling tricyclic guanidine fragments to prepare potential structures for batzelladine F. Eventually, a convergent synthesis strategy was devised, whose central step was a fragment-coupling tethered-Biginelli reaction (Scheme 17). Using this approach we synthesized four potential structures of batzelladine F, 35-38. None of these compounds, nor their enantiomers, were identical to natural batzelladine F. Reinvestigation of mass spectra of natural batzelladine F, and fragments 88 and 89 obtained upon saponification of batzelladine F, demonstrated that the originally proposed connectivity of this alkaloid was also incorrect. The revised connectivity, 90, of natural batzelladine F depicted in Scheme 21 is proposed.

| S-EPMC2535801 | biostudies-literature

Asymmetric catalytic synthesis of the proposed structure of trocheliophorolide B.

Project description:A concise catalytic asymmetric synthesis of the proposed structure of trocheliophorolide B is reported. The synthetic sequence notably features an asymmetric acetaldehyde alkynylation, a Ru-catalyzed alder-ene reaction, and a Zn-ProPhenol ynone aldol condensation. Comparison with the reported data suggests a misassignment of the natural product structure.

| S-EPMC3439167 | biostudies-literature

Total Synthesis and Structure Revision of Halioxepine.

Project description:The first total synthesis of halioxepine is accomplished using a 1,4-addition for constructing the quaternary center at C10 and a halo etherification for the generation of the tertiary ether at C7. The correct structure of halioxepine was determined by assembling different enantiomeric building blocks and by changing the relative configuration between C10 and C15.

| S-EPMC7898713 | biostudies-literature

The Formosalides: Structure Determination by Total Synthesis.

Project description:Total synthesis allowed the constitution of the cytotoxic marine macrolides of the formosalide family to be confirmed and their previously unknown stereostructure to be assigned with confidence. The underlying blueprint was inherently modular to ensure that each conceivable isomer could be reached. This flexibility derived from the use of strictly catalyst controlled transformations to set the stereocenters, except for the anomeric position, which is under thermodynamic control; as an extra safety measure, all stereogenic centers were set prior to ring closure to preclude any interference of the conformation adopted by the macrolactone rings of the different diastereomers. Late-stage macrocyclization by ring-closing alkyne metathesis was followed by a platinum-catalyzed transannular 6-exo-dig hydroalkoxylation/ketalization to craft the polycyclic frame. The side chain featuring a very labile unsaturation pattern was finally attached to the core by Stille coupling.

| S-EPMC7821135 | biostudies-literature

A convergent synthesis of the proposed structure of antitumor depsipeptide stereocalpin A.

Project description:The total synthesis of the proposed structure of anticancer agent stereocalpin A is described. The synthesis features a diastereoselective synthesis of a 5-hydroxy-2,4-dimethyl-3-oxooctanoic acid unit with asymmetric anti- and syn-aldol reactions as the key steps. Initial cycloamidation led to complete epimerization at the C-11 stereocenter due to unique steric constraints in the 12-membered depsipeptide ring. A late-stage methylation strategy led to the synthesis of the proposed structure of stereocalpin A.

| S-EPMC3179852 | biostudies-literature

Structure of FD-895 revealed through total synthesis.

Project description:The total synthesis of FD-895 was completed through a strategy that featured the use of a tandem esterification ring-closing metathesis (RCM) process to construct the 12-membered macrolide and a modified Stille coupling to append the side chain. These studies combined with detailed analysis of all four possible C16-C17 stereoisomers were used to confirm the structure of FD-895 and identify an analog with an enhanced subnanomolar bioactivity.

| S-EPMC3518397 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data