Coumaro-chalcones synthesized under solvent-free conditions as potential agents against malaria, leishmania and trypanosomiasis

Identification of a New Pentafluorosulfanyl-Substituted Chalcone with Activity Against Hepatoma and Human Parasites

BACKGROUND/OBJECTIVES

New drugs are required for the treatment of liver cancers and protozoal parasite infections. Analogs of the known anticancer active and antileishmanial 2',4',6'-trimethoxychalcone SU086 were prepared and investigated.

METHODS

The chalcones were prepared according to the Claisen-Schmidt condensation protocol and analyzed. They were tested for activity against two liver cancer cell lines (HepG2 and HuH-7) and protozoal parasites (Toxoplasma gondii and Leishmania major). Unspecific toxicity and expression of Hsp90 and Hsp70 upon treatment were analyzed in liver cancer cells.

RESULTS

A new chalcone, 2',4',6'-trimethoxy-3-pentafluorosulfanylchalcone (246TMP-3SF5), with a pentafluorosulfanyl (SF5) substituent showed pronounced activities against liver cancer cells and T. gondii parasites which were superior to the activities of the parent chalcone SU086 in these models. In contrast, SU086 and its anthracene analog 2',4',6'-trimethoxy-9-anthracenylchalcone (246TMP-Anth) were most active against L. major promastigotes. The new SF5-substituted chalcone behaved like the known Hsp90 inhibitor 17-AAG and upregulated Hsp70 expression in liver cancer cells.

CONCLUSIONS

The SF5-substituted SU086 analog has potential to become a new drug for the therapy of hepatoma and toxoplasmosis.

Antiparasitic Activity of Coumarin-Chalcone (3-Cinnamoyl-2H-Chromen-2-Ones) Hybrids

Coumarin-chalcone hybrids are promising compounds that could be used as lead structures in the fight against parasitic diseases. In this work, 16 hybrids of coumarin-chalcone (3-cinnamoyl-2H-chromen-2-ones) were synthesized, and their in vitro biological activity was evaluated against intracellular amastigotes of Leishmania braziliensis and Trypanosoma cruzi, as well as their cytotoxicity in the U-937 cell line. Compounds (E)-3-(3-(3-ethoxy-4-hydroxyphenyl)acryloyl)-7-methoxy-2H-chromen-2-one (H25) and (E)-7-(diethylamino)-3-(4-(methoxyphenyl)acryloyl)-2H-chromen-2-one (H12) showed the highest antileishmanial activity with EC50 values of 18.6 ± 3.5 and 25.6 ± 0.4 µM, respectively. In general, all 16 compounds exhibited moderate-to-high antitrypanosomal activity. The H25 hybrid also demonstrated the greatest antitrypanosomal activity, with an EC50 value of 13.2 ± 0.4 µM. Notably, the H25 hybrid displayed activity similar to that of benznidazole, which is known for its antiparasitic effects against T. cruzi. The results indicated that all compounds met the drug-like properties criteria. Taking into account the high antiparasitic activity of H25, a molecular docking study with the enzyme trypanothione reductase was performed. The substituent at C7 in the coumarinyl system is an important structural requirement for the antileishmanial and antitrypanosomal activities.

Exploring the Recent Pioneering Developments of Small Molecules in Antimalarial Drug Armamentarium: A Chemistry Prospective Appraisal

Malaria is a very destructive and lethal parasitic disease that causes significant mortality worldwide, resulting in the loss of millions of lives annually. It is an infectious disease transmitted by mosquitoes, which is caused by different species of the parasite protozoan belonging to the genus Plasmodium. The uncontrolled intake of antimalarial drugs often employed in clinical settings has resulted in the emergence of numerous strains of plasmodium that are resistant to these drugs, including multidrug-resistant strains. This resistance significantly diminishes the effectiveness of many primary drugs used in the treatment of malaria. Hence, there is an urgent need for developing unique classes of antimalarial drugs that function with distinct mechanisms of action. In this context, the design and development of hybrid compounds that combine pharmacophoric properties from different lead molecules into a single unit gives a unique perspective towards further development of malaria drugs in the next generation. In recent years, the field of medicinal chemistry has made significant efforts resulting in the discovery and synthesis of numerous small novel compounds that exhibit potent antimalarial properties, while also demonstrating reduced toxicity and desirable efficacy. In light of this, we have reviewed the progress of hybrid antimalarial agents from 2021 up to the present. This manuscript presents a comprehensive overview of the latest advancements in the medicinal chemistry pertaining to small molecules, with a specific focus on their potential as antimalarial agents. As possible antimalarial drugs that might target both the dual stage and multi-stage stages of the parasite life cycle, these small hybrid molecules have been studied. This review explores a variety of physiologically active compounds that have been described in the literature in order to lay a strong foundation for the logical design and eventual identification of antimalarial drugs based on lead frameworks.

Cocrystals of a coumarin derivative: an efficient approach towards anti-leishmanial cocrystals against MIL-resistant Leishmania tropica

Leishmaniasis is a neglected parasitic tropical disease with numerous clinical manifestations. One of the causative agents of cutaneous leishmaniasis (CL) is Leishmania tropica (L. tropica) known for causing ulcerative lesions on the skin. The adverse effects of the recommended available drugs, such as amphotericin B and pentavalent antimonial, and the emergence of drug resistance in parasites, mean the search for new safe and effective anti-leishmanial agents is crucial. Miltefosine (MIL) was the first recommended oral medication, but its use is now limited because of the rapid emergence of resistance. Pharmaceutical cocrystallization is an effective method to improve the physicochemical and biological properties of active pharmaceutical ingredients (APIs). Herein, we describe the cocrystallization of coumarin-3-carboxylic acid (CU, 1a; 2-oxobenzopyrane-3-carboxylic acid, C10H6O4) with five coformers [2-amino-3-bromopyridine (1b), 2-amino-5-(trifluoromethyl)-pyridine (1c), 2-amino-6-methylpyridine (1d), p-aminobenzoic acid (1e) and amitrole (1f)] in a 1:1 stoichiometric ratio via the neat grinding method. The cocrystals 2-6 obtained were characterized via single-crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis, as well as Fourier transform infrared spectroscopy. Non-covalent interactions, such as van der Waals, hydrogen bonding, C-H...π and π...π interactions contribute significantly towards the packing of a crystal structure and alter the physicochemical and biological activity of CU. In this research, newly synthesized cocrystals were evaluated for their anti-leishmanial activity against the MIL-resistant L. tropica and cytotoxicity against the 3T3 (normal fibroblast) cell line. Among the non-cytotoxic cocrystals synthesized (2-6), CU:1b (2, IC50 = 61.83 ± 0.59 µM), CU:1c (3, 125.7 ± 1.15 µM) and CU:1d (4, 48.71 ± 0.75 µM) appeared to be potent anti-leishmanial agents and showed several-fold more anti-leishmanial potential than the tested standard drug (MIL, IC50 = 169.55 ± 0.078 µM). The results indicate that cocrystals 2-4 are promising anti-leishmanial agents which require further exploration.

The green chemistry of chalcones: Valuable sources of privileged core structures for drug discovery

The sustainable use of resources is essential in all production areas, including pharmaceuticals. However, the aspect of sustainability needs to be taken into consideration not only in the production phase, but during the whole medicinal chemistry drug discovery trajectory. The continuous progress in the fields of green chemistry and the use of artificial intelligence are contributing to the speed and effectiveness of a more sustainable drug discovery pipeline. In this light, here we review the most recent sustainable and green synthetic approaches used for the preparation and derivatization of chalcones, an important class of privileged structures and building blocks used for the preparation of new biologically active compounds with a broad spectrum of potential therapeutic applications. The literature here reported has been retrieved from the SciFinder database using the term "chalcone" as a keyword and filtering the results applying the concept: "green chemistry", and from the Reaxys database using the keywords "chalcone" and "green". For both databases the time-frame was 2017-2022. References were manually selected based on relevance.