Antitumor and antileishmanial activities of limonene-thiosemicarbazones bearing heterocycles nucleous (original) (raw)

Synthesis and comparison of antileishmanial and cytotoxic activities of S-(−)-limonene benzaldehyde thiosemicarbazones with their R-(+)-analogues

Journal of Molecular Structure, 2018

In this study, we explore a series of novel potential antiprotozoal S-(−)-limonene-based benzaldehyde thiosemicarbazones were synthesized and their activity effective against the extracellular promastigote form of Leishmania amazonensis examined. Likewise, in parallel, a series of R-(+)-limonene-based thiosemicarbazones previously synthesized by our research group and thiosemicarbazones lacking the monoterpenic moiety, were also biologically evaluated. Here, we report the combination of theoretical and experimental approaches, as well as statistical analysis, to investigate the effect of the monoterpenic group and its stereochemistry in the biological activity of benzaldehyde thiosemicarbazone derivatives, for the identification of their structure-activity relationship. The terpenic thiosemicarbazones displayed the highest activities, confirming that the monoterpenic moiety is essential for activity. Notably, among the compounds tested, the S-(−)-enantiomer of the 4-nitro-derivative (8d) presented considerably lower cytotoxicity than its R-(+)-analogue, emphasizing the importance of the stereochemistry. The most active derivative (8d) exhibited a potent antiprotozoal activity (IC 50 2.4 µM) and high selectivity (SI >1147). Also, theoretical calculations were carried out at the density functional theory (DFT) level to show that the Gibbs free energy and LUMO orbitals present an excellent correlation with the experimental IC 50 values. Finally, the combination of all these results may in principle be extremely advantageous to a deeper chemical understanding, as well as, allows a rational alternative for the future development of new drugs that act against leishmaniasis.

Novel R-(+)-limonene-based thiosemicarbazones and their antitumor activity against human tumor cell lines

European Journal of Medicinal Chemistry, 2014

In an attempt to develop potent and selective antitumor agents, a series of novel thiosemicarbazones derived from a natural monoterpene R-(þ)-limonene was synthesized and their antitumor activity was evaluated. Overall, the majority of tested compounds exhibited considerable inhibitory effects on the growth of a wide range of cancer cell lines. Almost all of tested thiosemicarbazones were especially sensitive to prostate cells (PC-3). Derivatives 5, 6, 8, 9, 10, 11 and 13 presented the most potent antitumor activity against PC-3 cells. These compounds showed lower value of GI 50 (0.04e0.05 mM) than the reference drug paclitaxel, besides a high selectivity for the same cell line. The 4-fluorobenzaldehyde derivative 10 was the most selective compound for prostate cells, while 2-hydroxybenzaldehyde derivative 8 was the most active compound, with potent antitumor activity against all tested cell lines.

Evaluation of Novel Chalcone-Thiosemicarbazones Derivatives as Potential Anti-Leishmania amazonensis Agents and Its HSA Binding Studies

Biomolecules

A series of seven chalcone-thiosemicarbazones (5a–5g) were synthesized and evaluated as potential new drugs (anti-leishmanial effect). Although four of the chalcone-thiosemicarbazones are already known, none of them or any compound in this class has been previously investigated for their effects on parasites of the Leishmania genus. The compounds were prepared in satisfactory yields (40–75%) and these compounds were evaluated against promastigotes, axenic amastigotes and intracellular amastigotes of L. amazonensis after 48 h of culture. The half maximal inhibitory concentration (IC50) values of the intracellular amastigotes were determined to be in the range of 3.40 to 5.95 µM for all compounds assayed. The selectivity index showed value of 15.05 for 5a, whereas pentamidine (reference drug) was more toxic in our model (SI = 2.32). Furthermore, to understand the preliminary relationship between the anti-leishmanial activity of the chalcone-thiosemicarbazones, their electronic (σ), st...

Arylthiosemicarbazones as antileishmanial agents

European journal of medicinal chemistry, 2016

Based on a screening process, we targeted substituted thiosemicarbazone as potential antileishmanial agents. Our objective was to identify the key structural elements contributing to the anti-parasite activity that might be used for development of effective drugs. A series of 32 compounds was synthesized and their efficacy was evaluated against the clinically relevant intracellular amastigotes of Leishmania donovani. From these, 22 compounds showed EC50 values below 10 μM with the most active derivative (compound 14) showing an EC50 of 0.8 μM with very low toxicity on two different mammalian cell lines. The most relevant structural elements required for higher activity indicate that the presence of a fused bicyclic aromatic ring such as a naphthalene bearing an alkyl or an alkoxy group substituent are prerequisites. Owing to the easy synthesis, high activity and low toxicity, the most active compounds could be considered as a lead for further development.

Novel thiosemicarbazone derivatives as potential antitumor agents: Synthesis, physicochemical and structural properties, DNA interactions and antiproliferative activity

Bioorganic & Medicinal Chemistry, 2008

The paper describes synthesis of several novel thiosemicarbazone derivatives. Furthermore, crystal and molecular structure of 4-diethylamino-salicylaldehyde 4-phenylthiosemicarbazone revealed planarity of conjugated aromatic system, which suggested the possibility of DNA binding by intercalation, especially for here studied naphthalene derivatives. However, here presented DNA binding studies excluded this mode of action. Physicochemical and structural properties of novel derivatives were compared with previously studied analogues, taken as reference compounds, revealing distinctive differences. In addition, novel thiosemicarbazone derivatives (1, 2 and 5-8) clearly display stronger antiproliferative activity on five tumor cell lines than the reference compounds 3 and 4, which supports their further investigation as potential antitumor agents.

Synthesis and chemotherapeutic activities of 5-chloro-1H-indole-2,3-dione-3-thiosemicarbazones

MARMARA PHARMACEUTCAL JOURNAL, 2013

In the light of these findings, 5-chloro-1H-indole-2,3-dione 3-thiosemicarbazone derivatives were synthesized in order to obtain more potent and less toxic compounds. The structures of the ABSTRACT: A series of 5-chloro-1H-indole-2,3-dione 3-thiosemicarbazones 3a-g were synthesized to investigate the chemotherapeutic activities. The structures of 3a-g were confirmed by the spectral data (IR, 1 H NMR, 13 C NMR-APT, 13 C NMR-DEPT, HSQC, HMBC) and elemental analysis. Anticancer activities of the compounds were evaluated using cell kinetic parameters on HeLa cells derived from human cervix carcinoma. The preliminary screening results indicated that alkyl substituted compounds 3a, 3b and 3d were more effective in mitosis phase when compared to the synthesis phase. 3a-g were tested against some DNA and RNA viruses in CRFK, HeLa, HEL, MDCK and Vero cells. None of the compounds was active against any of the RNA or DNA viruses at 100 μM. All compounds were also evaluated for antimicrobial activity against selected strains. Methyl substituted 3a and allyl substituted 3c were found to be active against S. aureus and C. albicans.

Synthesis of limonene β-amino alcohol derivatives in support of new antileishmanial therapies

Memórias do Instituto Oswaldo Cruz, 2008

A series of seven limonene β-amino alcohol derivatives has been regioselectively synthesised in moderate to good yields. Two of these compounds were found to be significantly effective against in vitro cultures of the Leishmania (Viannia) braziliensis promastigote form in the micromolar range. The activities found for 3b and 3f were about 100-fold more potent than the standard drug, Pentamidine, in the same test, while limonene did not display any activity. This is the first report of antileishmanial activity by limonene β-amino alcohol derivatives.

Anti-leishmanial click modifiable thiosemicarbazones: Design, synthesis, biological evaluation and in silico studies

European Journal of Medicinal Chemistry, 2018

Leishmaniasis is a devastating tropical disease with limited therapeutic options. Depending on recently reported active anti-leishmanial compounds, we designed and synthesized a series of click modifiable 1,2,3-triazole and thiosemicarbazone hybrids. Most of the synthesized compounds showed comparable to superior activity to a well-established anti-leishmanial drug miltefosine. Compounds 2 and 10a showed nanomolar IC 50 s against promastigotes of L. major (227.4 nM and 140.3 nM respectively, vs 7.8 µM for miltefosine). Their antiamastigote IC 50 s were 1.4 µM and 1 µM respectively, which are 6 and 8 times the activity of miltefosine (IC 50 8.09 µM). Folic and folinic acids reversed the anti-leishmanial effects of compounds 2 and 10a and hence we anticipate they act via an anti-folate mechanism. They exhibited better safety profiles than that of miltefosine on VERO cell lines. Also they were relatively safe on experimental mice when administered via oral and parenteral routes. Docking experiments on PTR1 identified preferential binding interactions and docking scores. Finally, drug-likeness and ligand efficiency were assessed indicating that both 2 and 10a are promising hits and/or leads as anti-leishmanial chemotherapeutic agents.