Synthesis, structure, and estrogenic activity of 2- and 3-substituted 2,3-dihydro-4H-1-benzopyran-4-ones

Synthesis and evaluation of a new class of MIF-inhibitors in activated macrophage cells and in experimental septic shock in mice

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with enzymatic activities. Anti-inflammatory effects of MIF enzyme inhibitors indicate a link between its cytokine- and catalytic activities. Herein the synthesis, docking, and bioactivity of substituted benzylidene-1-indanone and -1-tetralone derivatives as MIF-tautomerase inhibitors is reported. Many of these substituted benzylidene-1-tetralones and -indan-1-ones were potent MIF-tautomerase inhibitors (IC₅₀ < 10 μmol/L), and the most potent inhibitors were the 1-indanone derivatives 16 and 20. Some of these compounds acted as selective enolase or ketonase inhibitors. In addition, compounds 16, 20, 26, 37 and 61 efficiently inhibited NO, TNFα and IL-6 production in lipopolysaccharide-induced macrophages. Compound 20, 37 and 61 also inhibited ROS generation, and compound 26 and 37 abolished activation of NF-κB. Compound 37 significantly augmented hypothermia induced by high dose of lipopolysaccharide in mice. The possible mechanisms of action were explored using molecular modelling and docking, as well as molecular dynamics simulations.

Design, synthesis and structure-activity relationship studies of novel spirochromanone hydrochloride analogs as anticancer agents

Aim: Literature reports suggest spirochromanone derivatives exhibit anticancer activity. Methodology: The authors designed and synthesized 18 spirochromanone derivatives (Csp 1-18). The compounds were characterized and evaluated for anticancer activity against human breast cancer (MCF-7) and murine melanoma (B16F10) cell lines. Results: The anticancer activity ranged from 4.34 to 29.31 μm. The most potent compounds, Csp 12 and Csp 18, were less toxic against the human embryonic kidney (HEK-293) cell line and ∼ two/∼four fold selective toward MCF-7 than B16F10 in comparison to the reference, BG-45. Csp 12 caused 28.6% total apoptosis, leading to significant cytotoxicity, and arrested the G2 phase of the cell cycle in B16F10 cells. A molecular docking study of Csp 12 exhibited effective binding at the active site of the epidermal growth factor receptor kinase domain. Conclusion: This study highlights the importance of spirochromanones as anticancer agents.

ERE-dependent transcription and cell proliferation: Independency of these two processes mediated by the introduction of a sulfone function into the weak estrogen estrothiazine

The synthetic coumestrol derivative 6,12-dihydro-3-methoxy-1-benzopyrano[3,4-b][1,4]benzothiazin-6-one (estrothiazine, ESTZ) has been identified as a weak estrogen receptor α (ERα) ligand unable to compete with tritiated estradiol. The biological activity of this compound, supported by a methoxy group in position 3, seems mainly to result from its capacity to activate ERα dimerization without any participation of coactivators. In support of this view and referring to conventional estrogens, an ESTZ metabolism study conducted with hepatic human microsomes failed to provide any argument in favour of an estrogenic activity dependent on a metabolic conversion of the compound into hydroxylated metabolites with strong receptor activation ability. Interestingly, we failed to detect any oxidation of the sulfur atom of the compound. In the light of pharmacological literature data concerning sulfonylation, we assessed ERα-mediated activities generated by two sulfonylated ESTZ derivatives in which the methoxy group that plays a key role in its mechanism of action was maintained or removed. Sulfonylated ESTZ, even in its demethoxylated form, induced ERE-mediated transcriptions in MCF-7 breast cancer cells, without affecting the ERα turnover rate. In contrast to ESTZ, this compound failed to enhance the proliferation of ERα-positive breast cancer cells, suggesting that its sulfone function confers upon the receptor a capacity to elicit some of the known characteristics associated with estrogenic responses. Moreover, we demonstrated that this sulfone may contribute to ERα dimerization without any requirement of the methoxy group. Nevertheless, it seems to cooperate with this group, as reflected by a weak ability of the sulfonylated form of ESTZ to compete with tritiated estradiol for ERα-binding. Assessment of the docking of this compound within the ligand-binding domain of the receptor by molecular dynamics provided an explanation for this observation since the sulfone is engulfed in a small hydrophobic pocket involving the residues Leu-346, Leu-349, Ala-350 and Leu-384, also known to recruit coactivators. This work not only reports the sulfone functional group as a pharmacophore for estrogenic activity, but also opens new perspectives for the development of estrogenic molecules with therapeutic purpose and devoid of proliferative side effects.

Synthesis and Biological Evaluation of 3-Benzylidene-4-chromanone Derivatives as Free Radical Scavengers and α-Glucosidase Inhibitors

A series of 3-benzylidene-4-chromanone derivatives (3-20) were synthesized and the structure-activity relationships for antioxidant and α-glucosidase inhibitory activities were evaluated. Among synthesized compounds, compounds 5, 13, 18, which contain catechol moiety, showed the potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (5: EC50 13 µM; 13: EC50 14 µM; 18: EC50 13 µM). The compounds 12, 14, 18 showed higher α-glucosidase inhibitory activity (12: IC50 15 µM; 14: IC50 25 µM; 18: IC50 28 µM). The compound 18 showed both of potent DPPH radical scavenging and α-glucosidase inhibitory activities. These data suggest that 3-benzylidene-4-chromanone derivatives, such as compound 18, may serve as the lead compound for the development of novel α-glucosidase inhibitors with antioxidant activity.

A short synthesis of 7-amino alkoxy homoisoflavonoides

The synthesis of novel derivatives of homoisoflavonoids as potentially interesting medicinally important heterocycles in an efficient catalytic alternative two-step route has been introduced.

ERα dimerization: a key factor for the weak estrogenic activity of an ERα modulator unable to compete with estradiol in binding assays

Estrothiazine (ESTZ) is a weak estrogen sharing structural similarities with coumestrol. ESTZ failed to compete with [³H]17β-estradiol ([³H]17β-E₂) for binding to the estrogen receptor α (ERα), questioning its ability to interact with the receptor. However, detection by atomic force spectroscopy (AFS) of an ESTZ-induced ERα dimerization has eliminated any remaining doubts. The effect of the compound on the proliferation of ERα-positive and negative breast cancer cells confirmed the requirement of the receptor. The efficiency of ESTZ in MCF-7 cells was weak without any potency to modify the proliferation profile of estradiol and coumestrol. Growth enhancement was associated with a proteasomal degradation of ERα without substantial recruitment of LxxLL coactivators. This may be related to an unusual delay between the acquisition by the receptor of an ERE-binding capacity and the subsequent estrogen-dependent transcription. A complementary ability to enhance TPA-induced AP-1 transcription was observed, even at concentrations insufficient to activate the ERα, suggesting a partly independent mechanism. ESTZ also rapidly and transiently activated ERK1/2 likely through membrane estrogenic pathways provoking a reorganization of the actin network. Finally, the systematic absence of biological responses with an ESTZ derivative unable to induce ERα dimerization stresses the importance of this step in the action of the compound, as reported for conventional estrogens. In view of the existence of many other ERα modulators (endocrine disruptors such as, for example, pesticides, environmental contaminants or phytoestrogens) with extremely weak or similar apparent lack of binding ability, our work may appear as pilot investigation for assessing their mechanism of action.

Construction of heterocyclic structures by trivalent cerium salts promoted bond forming reactions

Cerium(III) salts have recently gained increasing attention in the synthetic community, owing to the powerful features that are reviewed in detail in this tutorial. This review reports significant examples of cerium(III) promoted synthesis of heterocyclic structures, initially dealing with the synthesis of five- and six-membered ring nitrogen containing heterocycles, then describing the preparation of their oxygenated analogues and finally discussing the achievement of seven-membered rings and mixed heterocyclic motifs.