Anti-AIDS agents 86. Synthesis and anti-HIV evaluation of 2',3'-seco-3'-nor DCP and DCK analogues

Hybrid Heterocycles: Ag(I)-Catalyzed C-C/C-N/C-O Coupled Cascade Dual Cyclization to Valuable Indolo-4H-indolones and Indolo-4H-chromenes

Herein, we report a highly efficient Ag(I)-catalyzed indolyzation with Friedel-Crafts alkylation through a cascade cyclization strategy for accessing valuable hybrid heterocycles for the first time. This general strategy consists of forming four C-C/C-N/C-O bonds toward dual annulation reactions of 2-alkynylanilines with methyl benzoate-2-carboxaldehydes and aromatic amines, as well as with salicylaldehydes and malononitrile. Variably substituted new indolo-4H-phthalimidines and indolo-4H-chromenes were synthesized with excellent yields (85-93%) under mild reaction conditions.

Emerging computational approaches for the study of regio- and stereoselectivity in organic synthesis

Computational chemistry has become important in organic synthesis as it provides a detailed understanding of molecular structures and properties and detailed reaction mechanisms.

Antiviral efficiency of a coumarin derivative on spring viremia of carp virus in vivo

Spring viraemia of carp (SVC) in aquaculture is challenging because there are few preventative measures and/or treatments. The previous study demonstrated that an antiviral coumarin derivative, 7-(4-(4-methyl-imidazole))-coumarin (C2), inhibits spring viremia of carp virus (SVCV) infection by targeting Nrf2-ARE signaling pathway in fish cells. Thus, we hypothesized whether C2 may be used as a potential therapeutic agent for controlling SVCV infection in aquaculture. In this study, SVCV infectivity was significantly inhibited in vitro in a dose-dependent manner by preincubation with C2. C2 was verified against SVCV in zebrafish, in which the mortality and viral titer in fish body were decreased. Like other coumarins, C2 was stable with a prolonged inhibitory half-life (3.5 days) at 15 °C in the early stage of SVCV infection. The results show that horizontal transmission of SVCV was reduced by C2 in a static cohabitation challenge model, especially for recipient fish in injection treatment, which suggested that C2 may be suitable as a possible therapeutic agent for SVCV in aquaculture. Overall, this study provides the new insight that a small molecule antiviral drug can be used to control rhabdovirus infection in fish aquacultures.

Synthesis of 3-(Imidazo[2,1-b]thiazol-6-yl)-2H-chromen-2-one Derivatives and Study of Their Antiviral Activity against Parvovirus B19

Parvovirus B19 (B19V) is a human pathogenic virus associated with a wide range of clinical conditions. Currently, there are no recognized antiviral drugs for B19V treatment; therefore, efforts in the search for compounds inhibiting B19V replication are now being pursued. Coumarins (chromen-2-ones) are considered a privileged structure for designing novel orally bioavailable and non-peptidic antiviral agents. To further contribute to the development of new drugs against B19V, our research was focused on the synthesis, characterization and evaluation of antiviral activity of some new 3-(imidazo[2,1-b]thiazol-6-yl)-2H-chromen-2-one derivatives. The effects of the synthesized compounds on cell viability and viral replication were investigated by employing two relevant cellular systems, the myeloblastoid cell line UT7/EpoS1 and primary erythroid progenitor cells (EPCs). Some of the tested compounds showed inhibitory activity both on cell viability and on viral replication, depending on the cellular system. These results suggest that the mechanism involved in biological activity is sensitive to small structural changes and that it is possible to direct the activity of the 3-(imidazo[2,1-b]thiazol-6-yl)-2H-chromen-2-one core.

A new synthetic derivative of cryptotanshinone KYZ3 as STAT3 inhibitor for triple-negative breast cancer therapy

Silencing STAT3 is confirmed as a promising therapeutic strategy for triple-negative breast cancer (TNBC) therapy to address the issue of its poor prognosis. In this study, the natural product cryptotanshinone was firstly remodeled and modified as a more effective STAT3 inhibitor by structure-based strategy. The synthetic derivative KYZ3 had 22-24-fold increase in antitumor activity than cryptotanshinone on two TNBC cell lines but had little effect on normal breast epithelial MCF-10A cells. Further investigation showed that KYZ3 inhibited persistent STAT3 phosphorylation. It also prevented the STAT3 protein nuclear translocation to regulate the expressions of the target oncogenes including Bax and Bcl-2. Furthermore, KYZ3 inhibited TNBC cell metastasis by decreasing the levels of MMP-9 which were directly regulated by activated STAT3. A STAT3 plasmid transfecting assay suggested that KYZ3 induced tumor cell apoptosis mainly by targeting STAT3. Finally, KYZ3 suppressed the growth of tumors resulting from subcutaneous implantation of MDA-MB-231 cells in vivo. Taken together, KYZ3 may be a promising cancer therapeutic agent for TNBC.

One-pot three-component protocol for the synthesis of indolyl-4H-chromene-3-carboxamides as antioxidant and antibacterial agents

A series of newly synthesized 4-(1H-indol-3-yl)-2-methyl-N-phenyl-4H-chromene-3-carboxamide derivatives catalyzed by 1,4-Diazabicyclo [2.2.2]octane (DABCO) (30 mol%) at room temperature.

Therapeutic potential of coumarins as antiviral agents

Coumarins have received a considerable attention in the last three decades as a lead structures for the discovery of orally bioavailable non-peptidic antiviral agents. A lot of structurally diverse coumarins analogues were found to display remarkable array of affinity with the different molecular targets for antiviral agents and slight modifications around the central motif result in pronounced changes in its antiviral spectrum. This manuscript thoroughly reviews the design, discovery and structure-activity relationship studies of the coumarin analogues as antiviral agents focusing mainly on lead optimization and its development into clinical candidates.

A theoretical study of the Duff reaction: insights into its selectivity

The selectivity-determining step of the Duff ortho-formylation was studied using DFT calculations; a hydrogen bond establishes the position where the formylation will take place.

Application of Mannich bases to the synthesis of hydroxymethylated isoflavonoids as potential antineoplastic agents

The regiospecific Mannich aminomethylation of 7-hydroxyisoflavonoids using bis(N,N-dimethylamino)methane afforded C-8 substituted N,N-dimethylaminomethyl adducts, and the regioselective aminomethylation of 5-hydroxy-7-methoxyisoflavonoids afforded predominantly the C-6 substituted N,N-dimethylaminomethyl adducts. Acetylation of these C-6 or C-8 Mannich bases with potassium acetate in acetic anhydride provided access to the corresponding acetoxymethyl derivatives that were subsequently converted to hydroxymethyl- and methoxymethyl-substituted 5-hydroxy- or 7-hydroxyisoflavonoids related to naturally occurring flavonoids. The C-8 acetoxymethyl, hydroxymethyl or methoxymethyl-substituted isoflavonoids possessed promising inhibitory potency in the low micromolar range in a prostate cancer PC-3 cell proliferation assay.

Synthesis and tautomerization of hydroxylated isoflavones bearing heterocyclic hemi-aminals

The aminomethylation of hydroxylated isoflavones with 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol in the presence of excess formaldehyde led principally to 9-(2-hydroalkyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]-oxazin-4-ones 4 and/or the tautomeric 7-hydroxy-8-(1,3-oxazepan-3-ylmethyl)-4H-chromen-4-ones 5. The ratio of these tautomers was dependent on solvent polarity, electronic effects of aryl substituents in the isoflavone and the structure of the amino alcohol. NMR studies confirmed the interconversion of tautomeric forms.

3(2H)-Furanone as a promising scaffold for the synthesis of novel fluorescent organic dyes: an experimental and theoretical investigation

Novel 3(2H)-furanone compounds have been synthesised and characterized. Experimental and theoretical studies indicated that these compounds exhibit interesting solvatochromic effects.

Advances in chemistry of chromone aminomethyl derivatives

Chromones play an important role in the design and discovery of new pharmacologically active compounds. A large volume of reports dedicated to synthesis and study of properties of nitrogen-containing chromone derivatives show important role of chromone alkaloid-like compounds. The present review covers achievements in the field of synthesis of chromone aminomethyl derivatives as one of perspective scaffolds.

Antitumor agents 292. Design, synthesis and pharmacological study of S- and O-substituted 7-mercapto- or hydroxy-coumarins and chromones as potent cytotoxic agents

Thirty-five S- and O-substituted 7-mercaptocoumarin (9-23) and 7-hydroxy- or 7-mercapto-chromone (24-43) analogs were designed, synthesized and evaluated in vitro against four human tumor cell lines [KB (nasopharyngeal), KB-vin (vincristine-resistant subline), A549 (lung) and DU145 (prostate)] with paclitaxel as the positive control. Many of the synthesized compounds exhibited potent cytotoxic activity. Among them, compounds 10 and 18 showed broad spectrum activity with GI(50) values ranging from 0.92 to 2.11 μM and 2.06-14.07 μM, respectively. However, 33, a 3-brominated compound, displayed significant and selective inhibition against MDR KB-vin with a GI(50) of 5.84 μM. Regardless of the size of the 7-alkoxy group, 2-α-bromoethyl-8-bromomethyl compounds (40-43) exhibited increased cytotoxicity compared with 2-ethyl-8-bromomethyl compounds (36-39). Moreover, in a preliminary pharmacological study, 10 not only remarkably increased cellular apoptosis in a concentration-dependent manner, but also clearly induced A549 cell cycle arrest at the G2/M phase. Thus, these coumarin derivatives merit investigation as novel potential antitumor agents with further structural modification to produce an optimal lead compound and elucidate the detailed pharmacological mechanism(s).