3,4-Dimethoxychalcone

A discovery platform for the identification of caloric restriction mimetics with broad health-improving effects.[Pubmed:31690168]

Autophagy. 2020 Jan;16(1):188-189.

The age-related decline in organismal fitness results in vulnerability to pathologies and eventual lethal decay. One way to counteract cellular aging and to delay and/or prevent the onset of age-related maladies is the reduction of calorie intake or the institution of fasting regimens. Caloric restriction mimetics (CRMs) have the ability to imitate the health-promoting and lifespan-extending effects of caloric restriction without the need for dietary restriction. CRMs induce an increase in autophagic flux in response to the deacetylation of cellular proteins in the absence of cytotoxicity. Here we report the development of a high-throughput discovery platform for novel CRMs that uses systems biology approaches, in vitro validation and functional tests employing in vivo disease models. This workflow led to the identification of 3,4-Dimethoxychalcone (3,4-DC) as a novel CRM that stimulated TFEB (transcription factor EB)- and TFE3 (transcription factor E3)-dependent macroautophagy/autophagy. 3,4-DC showed cardioprotective effects and stimulated anticancer immunosurveillance in the context of immunogenic chemotherapy.

3,4-Dimethoxychalcone induces autophagy through activation of the transcription factors TFE3 and TFEB.[Pubmed:31609086]

EMBO Mol Med. 2019 Nov 7;11(11):e10469.

Caloric restriction mimetics (CRMs) are natural or synthetic compounds that mimic the health-promoting and longevity-extending effects of caloric restriction. CRMs provoke the deacetylation of cellular proteins coupled to an increase in autophagic flux in the absence of toxicity. Here, we report the identification of a novel candidate CRM, namely 3,4-Dimethoxychalcone (3,4-DC), among a library of polyphenols. When added to several different human cell lines, 3,4-DC induced the deacetylation of cytoplasmic proteins and stimulated autophagic flux. At difference with other well-characterized CRMs, 3,4-DC, however, required transcription factor EB (TFEB)- and E3 (TFE3)-dependent gene transcription and mRNA translation to trigger autophagy. 3,4-DC stimulated the translocation of TFEB and TFE3 into nuclei both in vitro and in vivo, in hepatocytes and cardiomyocytes. 3,4-DC induced autophagy in vitro and in mouse organs, mediated autophagy-dependent cardioprotective effects, and improved the efficacy of anticancer chemotherapy in vivo. Altogether, our results suggest that 3,4-DC is a novel CRM with a previously unrecognized mode of action.

Identification of heme oxygenase-1 stimulators by a convenient ELISA-based bilirubin quantification assay.[Pubmed:25462643]

Free Radic Biol Med. 2015 Jan;78:135-46.

The upregulation of heme oxygenase-1 (HO-1) has proven to be a useful tool for fighting inflammation. In order to identify new HO-1 inducers, an efficient screening method was developed which can provide new lead structures for drug research. We designed a simple ELISA-based HO-1 enzyme activity assay, which allows for the screening of 12 compounds in parallel in the setting of a 96-well plate. The well-established murine macrophage cell line RAW264.7 is used and only about 26microg of protein from whole cell lysates is needed for the analysis of HO-1 activity. The quantification of HO-1 activity is based on an indirect ELISA using the specific anti-bilirubin antibody 24G7 to quantify directly bilirubin in the whole cell lysate, applying a horseradish peroxidase-tagged antibody together with ortho-phenylenediamine and H2O2 for detection. The bilirubin is produced on the action of HO enzymes by converting their substrate heme to biliverdin and additional recombinant biliverdin reductase together with NADPH at pH 7.4 in buffer. This sensitive assay allows for the detection of 0.57-82pmol bilirubin per sample in whole cell lysates. Twenty-three small molecules, mainly natural products with an alpha,beta-unsaturated carbonyl unit such as polyphenols, including flavonoids and chalcones, terpenes, an isothiocyanate, and the drug oltipraz were tested at typically 6 or 24h incubation with RAW264.7 cells. The activity of known HO-1 inducers was confirmed, while the chalcones cardamonin, flavokawain A, calythropsin, 2',3,4'-trihydroxy-4-methoxychalcone (THMC), and 2',4'-dihydroxy-3,4-Dimethoxychalcone (DHDMC) were identified as new potent HO-1 inducers. The highest inductive power after 6h incubation was found at 10microM for DHDMC (6.1-fold), carnosol (3.9-fold), butein (3.1-fold), THMC (2.9-fold), and zerumbone (2.5-fold). Moreover, the time dependence of HO-1 protein production for DHDMC was compared to its enzyme activity, which was further evaluated in the presence of lipopolysaccharide and the specific HO-1 inhibitor tin protoporphyrin IX. Taken together, we developed a convenient and highly sensitive ELISA-based HO-1 enzyme activity assay, allowing the identification and characterization of molecules potentially useful for the treatment of inflammatory and autoimmune diseases.

A new O-prenylated flavonol from the roots of Sophora interrupta.[Pubmed:23406166]

Nat Prod Res. 2013 Oct;27(20):1823-6.

A new O-prenylated flavonol, 3',4'-dimethoxy-7-(gamma,gamma-dimethylallyloxy)flavonol (1), together with three known compounds, 2'-hydroxy-3,4-Dimethoxychalcone (2), biochanin A (3) and kaempferol-3-O-beta-D-glucopyranoside (4), were isolated from the roots of Sophora interrupta Bedd. The structure of compound 1 was elucidated by extensive 1D and 2D NMR spectral studies.

Synthesis and evaluation of 2',4',6'-trihydroxychalcones as a new class of tyrosinase inhibitors.[Pubmed:17267225]

Bioorg Med Chem. 2007 Mar 15;15(6):2396-402.

In this study, we synthesized a series of hydroxychalcones and examined their tyrosinase inhibitory activity. The results showed that 2',4',6'-trihydroxychalcone (1), 2,2',3,4',6'-pentahydroxychalcone (4), 2',3,4,4',5,6'-hexahydroxychalcone (5), 2',4',6'-trihydroxy- 3,4-Dimethoxychalcone (9) and 2,2',4,4',6'-pentahydroxychalcone (15) exhibited high inhibitory effects on tyrosinase with respect to l-tyrosine as a substrate. By the structure-activity relationship study, it was suggested that the 2',4',6'-trihydroxyl substructure in the chalcone skeleton were efficacious for the inhibition of tyrosinase activity. And also, the catechol structure on B-ring of chalcones was not advantageous for the inhibitory potency. Furthermore, 15 (IC(50)=1microM) was found to show the highest activity out of a set of 15 hydroxychalcones, even better than both 2,2',4,4'-tetrahydroxychalcone (13, IC(50)=5microM) and kojic acid (16, IC(50)=12microM), which were known as potent tyrosinase inhibitors. Kinetic study revealed that 15 acts as a competitive inhibitor of tyrosinase with K(i) value of 3.1microM.

In vitro leishmanicidal activity of naturally occurring chalcones.[Pubmed:11268116]

Phytother Res. 2001 Mar;15(2):148-52.

A variety of chalcones have been shown to exhibit activity against Leishmania parasites. In contrast to synthetic or semisynthetic chalcones, only a few plant-derived compounds have been investigated. To provide a scientific rational for the antiprotozoal potency of plants used in ethnomedicine and containing chalcones, and in the search for new antiprotozoal drugs, we have carried out a primary screening for in vitro leishmanicidal activity of 20 chalcones isolated from plants. The compounds were tested against extracellular promastigotes of Leishmania donovani, L. infantum, L. enrietii and L. major, and against intracellular amastigote L. donovani residing within murine macrophages. Against the extracellular Leishmania (L. donovani), most compounds were active with EC(50) values between 0.07 and 2.01 microg/mL. Some of these chalcones, 2',4'-dihydroxy-4-methoxychalcone, 2'-hydroxy-3,4-Dimethoxychalcone and 2-hydroxy-4,4'-dimethoxychalcone also significantly inhibited the intracellular survival of L. donovani parasites with EC(50) values between 0.39 and 0.41 microg/mL. When tested against murine bone marrow-derived macrophages as a mammalian host cell control, all compounds with antileishmanial activities also proved to be cytotoxic to varying extents (EC(50) 0.19-2.06 microg/mL). Correlations between molecular structures and antileishmanial activity are discussed in detail. Specific compounds are illustrated with emphasis on their mode of action and potential for the development of selective antiprotozoal agents.