chroman 1

IC50: <1 nM for ROCK-II

Chroman 1 is a highly potent ROCK-II inhibitor. ROCK is a member of the AGC kinase family of serine/threonine kinases that is comprised of two highly homologous isoforms, which are ROCK-I and ROCK-II.. As one of the downstream effectors of RhoA, ROCK regulates stress fiber formation and actin cytoskeletal organization via phosphorylation of myosin light chain. Currently, there is plenty of interest in the inhibition of Rho kinase (ROCK) to treat various diseases.

In vitro: Chroman 1 was found to be a sub-nanomolar ROCK-II inhibitor with excellent to moderate selectivity over related kinases studied as a preliminary assessment, such as AKT1, protein kinase A (PKA), and the highly homologous Cdc42-binding kinase. In addition, Chroman 1 also showed good in-vitro activity in the functional cell-based myosin light chain bis-phosphorylation assay [1].

In vivo: Pharmacokinetic evaluation in rats showed that Chroman 1 had moderately improved oral bioavailability (27–35%) relative to its lead compounds, which were benzodioxane and chroman. In addition, Chroman 1 also displayed an unique intriguing pharmacokinetic profile, which was with high systemic exposure through oral delivery [1].

Clinical trial: So far, there is no clinical study reported.

References:
[1] Chen YT,Bannister TD,Weiser A,Griffin E,Lin L,Ruiz C,Cameron MD,Schürer S,Duckett D,Schrter T,LoGrasso P,Feng Y.  Chroman-3-amides as potent Rho kinase inhibitors. Bioorg Med Chem Lett.2008 Dec 15;18(24):6406-9.

Chroman-4-One Derivatives Targeting Pteridine Reductase 1 and Showing Anti-Parasitic Activity.[Pubmed:28282886]

Molecules. 2017 Mar 8;22(3). pii: molecules22030426.

Flavonoids have previously been identified as antiparasitic agents and pteridine reductase 1 (PTR1) inhibitors. Herein, we focus our attention on the chroman-4-one scaffold. Three chroman-4-one analogues (1-3) of previously published chromen-4-one derivatives were synthesized and biologically evaluated against parasitic enzymes (Trypanosoma brucei PTR1-TbPTR1 and Leishmania major-LmPTR1) and parasites (Trypanosoma brucei and Leishmania infantum). A crystal structure of TbPTR1 in complex with compound 1 and the first crystal structures of LmPTR1-flavanone complexes (compounds 1 and 3) were solved. The inhibitory activity of the chroman-4-one and chromen-4-one derivatives was explained by comparison of observed and predicted binding modes of the compounds. Compound 1 showed activity both against the targeted enzymes and the parasites with a selectivity index greater than 7 and a low toxicity. Our results provide a basis for further scaffold optimization and structure-based drug design aimed at the identification of potent anti-trypanosomatidic compounds targeting multiple PTR1 variants.

Crystal structure of 1'-ethyl-spiro[chroman-4,4'-imidazolidine]-2',5'-dione: a hydantoine derivative.[Pubmed:26594433]

Acta Crystallogr E Crystallogr Commun. 2015 Sep 12;71(Pt 10):o705-6.

The title compound, C13H13N2O3, a hydantoin derivative, crystallized with two mol-ecules (A and B) in an asymmetric unit. In mol-ecule A, the imidazolidine ring is twisted about the C-N bond involving the spiro C atom, while in mol-ecule B this ring is flat (r.m.s. deviation = 0.010 A). The pyran rings in both mol-ecules have distorted half-chair conformations. The mean plane of the imidazolidine ring is inclined to the aromatic ring of the chroman unit by 79.71 (11) degrees in mol-ecule A and 82.83 (12) degrees in mol-ecule B. In the crystal, pairs of N-Hcdots, three dots, centeredO hydrogen bonds link the individual mol-ecules to form A-A and B-B inversion dimers. The dimers are linked via N-Hcdots, three dots, centeredO and C-Hcdots, three dots, centeredO hydrogen bonds, forming sheets lying parallel to the bc plane, viz. (011). Within the sheets, the A and B mol-ecules are linked by C-Hcdots, three dots, centeredpi inter-actions.

Crystal structure determination as part of an undergraduate laboratory experiment: 1',3',3'-tri-methyl-spiro-[chromene-2,2'-indoline] and 1',3',3'-trimethyl-4-[(E)-(1,3,3-tri-methyl-indolin-2-yl-idene)meth-yl]spiro-[chr oman-2,2'-indoline].[Pubmed:27840731]

Acta Crystallogr E Crystallogr Commun. 2016 Oct 28;72(Pt 11):1659-1662.

The crystal structures of the title compounds, C19H19NO and C31H34N2O, were determined as part of an experiment in an undergraduate teaching laboratory that demonstrates the relationship between mol-ecular structure and function. 1',3',3'-Tri-methyl-spiro-[chromene-2,2'-indoline] is both a photoswitch and thermochromic mol-ecule. Students synthesized it and a bis-indoline adduct and compared the crystallographically determined structures to computed gas-phase models.

Discovery of (R)-1-(7-chloro-2,2-bis(fluoromethyl)chroman-4-yl)-3-(3-methylisoquinolin-5-yl)ur ea (A-1165442): a temperature-neutral transient receptor potential vanilloid-1 (TRPV1) antagonist with analgesic efficacy.[Pubmed:25100568]

J Med Chem. 2014 Sep 11;57(17):7412-24.

The synthesis and characterization of a series of selective, orally bioavailable 1-(chroman-4-yl)urea TRPV1 antagonists is described. Whereas first-generation antagonists that inhibit all modes of TRPV1 activation can elicit hyperthermia, the compounds disclosed herein do not elevate core body temperature in preclinical models and only partially block acid activation of TRPV1. Advancing the SAR of this series led to the eventual identification of (R)-1-(7-chloro-2,2-bis(fluoromethyl)chroman-4-yl)-3-(3-methylisoquinolin-5-yl)ur ea (A-1165442, 52), an analogue that possesses excellent pharmacological selectivity, has a favorable pharmacokinetic profile, and demonstrates good efficacy against osteoarthritis pain in rodents.