RESUMO
Succinate dehydrogenase (SDH) and fumarate hydratase (FH) are components of the tricarboxylic acid (TCA) cycle and tumor suppressors. Loss of SDH or FH induces pseudohypoxia, a major tumor-supporting event, which is the activation of hypoxia-inducible factor (HIF) under normoxia. In SDH- or FH-deficient cells, HIF activation is due to HIF1alpha stabilization by succinate or fumarate, respectively, either of which, when in excess, inhibits HIFalpha prolyl hydroxylase (PHD). To reactivate PHD, we focused on its substrate, alpha-ketoglutarate. We designed and synthesized cell-permeating alpha-ketoglutarate derivatives, which build up rapidly and preferentially in cells with a dysfunctional TCA cycle. This study shows that succinate- or fumarate-mediated inhibition of PHD is competitive and is reversed by pharmacologically elevating intracellular alpha-ketoglutarate. Introduction of alpha-ketoglutarate derivatives restores normal PHD activity and HIF1alpha levels to SDH-suppressed cells, indicating new therapy possibilities for the cancers associated with TCA cycle dysfunction.
Assuntos
Hipóxia Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular , Ácidos Cetoglutáricos/química , Ácidos Cetoglutáricos/farmacologia , Succinato Desidrogenase/deficiência , Succinato Desidrogenase/metabolismo , Linhagem Celular , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ácidos Cetoglutáricos/metabolismo , Estrutura Molecular , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Succinato Desidrogenase/genética , Ubiquitina/metabolismoRESUMO
We report the design, synthesis, and biological evaluation of some potent small-molecule neuropilin-1 (NRP1) antagonists. NRP1 is implicated in the immune response to tumors, particularly in Treg cell fragility, required for PD1 checkpoint blockade. The design of these compounds was based on a previously identified compound EG00229. The design of these molecules was informed and supported by X-ray crystal structures. Compound 1 (EG01377) was identified as having properties suitable for further investigation. Compound 1 was then tested in several in vitro assays and was shown to have antiangiogenic, antimigratory, and antitumor effects. Remarkably, 1 was shown to be selective for NRP1 over the closely related protein NRP2. In purified Nrp1+, FoxP3+, and CD25+ populations of Tregs from mice, 1 was able to block a glioma-conditioned medium-induced increase in TGFß production. This comprehensive characterization of a small-molecule NRP1 antagonist provides the basis for future in vivo studies.
Assuntos
Imunomodulação/efeitos dos fármacos , Neuropilina-1/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/biossíntese , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Desenho de Fármacos , Humanos , Camundongos , Modelos Moleculares , Conformação Molecular , Ácidos Pentanoicos/química , Ácidos Pentanoicos/farmacologia , Bibliotecas de Moléculas Pequenas/química , Linfócitos T Reguladores/imunologia , Fator A de Crescimento do Endotélio Vascular/farmacologiaRESUMO
The first syntheses of two natural products, catechols 1 and 2, isolated from Plectranthus sylvestris (labiatae), are reported. Oxygen-18 labeling studies support the proposed intermediacy of a stabilized benzylic cation in the acid-promoted cyclization of an aldehyde and benzylic homoallylic alcohol possessing an electron-rich aromatic ring. In contrast, with an electron-deficient aromatic ring the pathway via a benzylic cation is only minor. [reaction: see text]
Assuntos
Fatores Biológicos/síntese química , Catecóis/síntese química , Ciclização , Anti-Inflamatórios/síntese química , Antioxidantes/síntese química , Lamiaceae/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , EstereoisomerismoRESUMO
[reaction: see text] Evidence is presented here for the mechanism of the Prins cyclization of benzylic homoallylic alcohols, which shows that the outcome of the reaction is dependent upon the substituents on the aromatic ring. The presence of an electron-rich aromatic ring favors an oxonia-Cope rearrangement yielding a symmetrical tetrahydropyran as the major product formed via a side-chain exchange process. In contrast, with electron-deficient aromatic rings the expected 2,4,6-trisubstituted tetrahydropyran is formed.
RESUMO
[reaction: see text] Reaction of homoallylic alcohols with aldehydes in the presence of TFA gives, after hydrolysis of the ester, 4-hydroxy-2,3,6-trisubstituted tetrahydropyrans with the creation of three new stereocenters in a single-pot process. By varying the aldehyde component, a variety of functionalized side chains are installed at C-2. The utility of this approach is extended to the enantioselective synthesis of tetrahydropyrans with >99% ee.