Browse
Submit Data
Databases
API
Help

Dataset Information

31 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cryptocaryols A and B: total syntheses, stereochemical revision, structure elucidation, and structure-activity relationship.

ABSTRACT: The first total syntheses and structural elucidation of cryptocaryol A and cryptocaryol B were achieved in 23 and 25 linear steps, respectively. The synthesis relied on the use of a key pseudo-Cs symmetric pentaol intermediate, which in a stereochemically divergent manner was converted into either enantiomer as well as diastereomers. This synthetic effort enabled the first structure-activity relationships of this class of PDCD4 stabilizing natural products.

SUBMITTER: Wang Y

PROVIDER: S-EPMC3772640 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Cryptocaryols A and B: total syntheses, stereochemical revision, structure elucidation, and structure-activity relationship.

Wang Yanping Y O'Doherty George A GA

Journal of the American Chemical Society 20130614 25

The first total syntheses and structural elucidation of cryptocaryol A and cryptocaryol B were achieved in 23 and 25 linear steps, respectively. The synthesis relied on the use of a key pseudo-Cs symmetric pentaol intermediate, which in a stereochemically divergent manner was converted into either enantiomer as well as diastereomers. This synthetic effort enabled the first structure-activity relationships of this class of PDCD4 stabilizing natural products. ...[more]

PMID: 23750754

Similar Datasets

Enantioselective total syntheses of citrinadins A and B. Stereochemical revision of their assigned structures.

Project description:The concise, enantioselective total syntheses of (-)-citrinadin A and (+)-citrinadin B in a total of only 20 and 21 steps, respectively, from commercially available starting materials are described. Our strategy, which minimizes refunctionalization and protection/deprotection operations, features the highly diastereoselective, vinylogous Mannich addition of a dienolate to a chiral pyridinium salt to set the first chiral center. The absolute stereochemistry of this key center was then relayed by a sequence of substrate-controlled reactions, including a highly stereoselective epoxidation/ring opening sequence and an oxidative rearrangement of an indole to furnish a spirooxindole to establish the remaining stereocenters in the pentacyclic core of the citrinadins. An early stage intermediate in the synthesis of (-)-citrinadin A was deoxygenated to generate a dehydroxy compound that was elaborated into (+)-citrinadin B by a sequence of reaction identical to those used to prepare (-)-citrinadin A. These concise syntheses of (-)-citrinadin A and (+)-citrinadin B led to a revision of their stereochemical structures.

| S-EPMC4195386 | biostudies-literature

Enantioselective total synthesis of (-)-citrinadin A and revision of its stereochemical structure.

Project description:The first enantioselective total synthesis of (-)-citrinadin A has been accomplished in 20 steps from commercially available materials via an approach that minimizes refunctionalization and protection/deprotection operations. The cornerstone of this synthesis features an asymmetric vinylogous Mannich addition of a dienolate to a chiral pyridinium salt to set the initial chiral center. A sequence of substrate-controlled reactions, including a highly stereoselective epoxidation/ring-opening sequence and an oxidative rearrangement of an indole to furnish a spirooxindole, are then used to establish the remaining stereocenters in the pentacyclic core of (-)-citrinadin A. The successful synthesis of citrinadin A led to a revision of the stereochemical structure of the core substructure of the citrinadins.

| S-EPMC3748604 | biostudies-literature

Coibacins A and B: total synthesis and stereochemical revision.

Project description:The interface between synthetic organic chemistry and natural products was explored in order to unravel the structure of coibacin A, a metabolite isolated from the marine cyanobacterium cf. Oscillatoria sp. that exhibits selective antileishmanial activity and potent anti-inflammatory properties. Our synthetic plan focused on a convergent strategy that allows rapid access to the desired target by coupling of three key fragments involving E-selective Wittig and modified Julia olefinations. CD measurements and comparative HPLC analyses of the natural product and four synthetic stereoisomers led to determination of its absolute configuration, thus correcting the original assignment at C-5 and unambiguously establishing those at C-16 and C-18. Additionally, we synthesized coibacin B on the basis of the assignment of configuration for coibacin A.

| S-EPMC3962765 | biostudies-literature

Stereochemical Structure Activity Relationship Studies (S-SAR) of Tetrahydrolipstatin.

Project description:Tetrahydrolipstatin (THL), its enantiomer, and an additional six diastereomers were evaluated as inhibitors of the hydrolysis of p-nitrophenyl butyrate by porcine pancreatic lipase. IC50s were found for all eight stereoisomers ranging from a low of 4.0 nM for THL to a high of 930 nM for the diastereomer with the inverted stereocenters at the 2,3,2'-positions. While the enantiomer of THL was also significantly less active (77 nM) the remaining five stereoisomers retained significant inhibitory activities (IC50s = 8.0 to 20 nM). All eight compounds were also evaluated against three human cancer cell lines (human breast cancers MCF-7 and MDA-MB-231, human large-cell lung carcinoma H460). No appreciable cytotoxicity was observed for THL and its seven diastereomers, as their IC50s in a MTT cytotoxicity assay were all greater than 3 orders of magnitude of camptothecin.

| S-EPMC5846039 | biostudies-literature

An enantioselective total synthesis and stereochemical revision of (+)-citrinadin B.

Project description:This manuscript describes an enantioselective synthesis of the naturally occurring alkaloid citrinadin B. The synthetic effort revealed an anomaly in the original structural assignment that has led to the proposal of a stereochemical revision. This revision is consistent with the structures previously reported for a closely related family of alkaloids, PF1270A-C. The synthesis is convergent and employs a stereoselective intermolecular nitrone cyloaddition reaction as a key step.

| S-EPMC6775640 | biostudies-literature

10-Step Asymmetric Total Synthesis and Stereochemical Elucidation of (+)-Dragmacidin D.

Project description:The asymmetric synthesis of dragmacidin D (1) was completed in 10 steps. Its sole stereocenter was set by using direct asymmetric alkylation enabled by a C2-symmetric tetramine and lithium N-(trimethylsilyl)-tert-butylamide as the enolization reagent. A central Larock indole synthesis was employed in a convergent assembly of the heterocyclic subunits. The stereochemical evidence from this work strongly supports the predicted S configuration at the 6''' position, which is consistent with other members of the dragmacidin family of natural products.

| S-EPMC4532559 | biostudies-literature

Studies toward the unique pederin family member psymberin: full structure elucidation, two alternative total syntheses, and analogs.

Project description:Two synthetic approaches to psymberin have been accomplished. A highly convergent first generation synthesis led to the complete stereochemical assignment and demonstrated that psymberin and irciniastatin A are identical compounds. This synthesis featured a diastereoselective aldol coupling between the aryl fragment and a central tetrahydropyran core and a novel one-pot procedure to convert an amide, via intermediacy of a sensitive methyl imidate, to the N-acyl aminal reminiscent of psymberin. The highlights of the second generation synthesis include an efficient iridium-catalyzed enantioselective bisallylation of neopentyl glycol and a stepwise Sonogashira coupling/cycloisomerization/reduction sequence to construct the dihydroisocoumarin unit. The two synthetic avenues were achieved in 17-18 steps (longest linear sequence, ~14-15 isolations) from 3 fragments prepared in 7-8 (first generation) and 3-8 (second generation) steps each. This convergent approach allowed for the preparation of sufficient amounts of psymberin (~ 0.5 g) for follow-up biological studies. Meanwhile, our highly flexible strategy enabled the design and synthesis of multiple analogs, including a psymberin-pederin hybrid, termed psympederin, that proved crucial to a comprehensive understanding of the chemical biology of psymberin and related compounds that will be described in a subsequent manuscript.

| S-EPMC3482988 | 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

Antitumor agents 259. Design, syntheses, and structure-activity relationship study of desmosdumotin C analogs.

Project description:Desmosdumotin C (1) and its analogs previously showed potent, selective in vitro anticancer activity. To explore structure-activity relationships of 1 and further increase potency and selectivity, 15 novel analogs (7-15 and 21-26) were synthesized and evaluated for cytotoxity against several human tumor cell lines, as well as inhibition of human endothelial (HUVEC) replication. 4-Bromo-3',3',5'-tripropyl analog 26 showed significant cytotoxity against A549, A431, 1A9, and HCT-8 with ED50 values of 1.0, 1.2, 0.9, and 1.3 mug/mL, respectively. Compound 26 also strongly inhibited the growth of matched tumor cells, KB-VIN and its parent cell KB. Furthermore, analogs 13 and 21 were over 5-fold more potent against KB-VIN than KB. Bromination of ring-B and tripropyl functionalization of ring-A enhanced activity, while alkylation of ring-B promoted KB-VIN/KB selectivity. 2-Furyl analog 16 showed selective activity against HUVEC, suggesting that it may have potential as a new prototype for angiogenesis inhibition.

| S-EPMC2526252 | biostudies-literature

Total synthesis of Ciliatamides A-C: stereochemical revision and the natural product-guided synthesis of unnatural analogs.

Project description:The first total synthesis of Ciliatamides A-C was completed, leading to a revision of the reported stereochemistry from (S,S) to the (R,R) enantiomers. Due to the expedited route, a library of over 50 unnatural ciliatamide analogs was also prepared.

| S-EPMC3177603 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

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