Antiproliferative and Antiprostate Cancer Activities of Heterocyclic Compounds Derived from Cyclohexane-1,4-dione

2-Amino-6-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (3) was prepared from the reaction of cyclohexane-1,4-dione with elemental sulfur and malononitrile in 1,4-dioxane and triethylamine as catalyst. The latter compound reacted with triethyl orthoformate and either malononitrile or ethyl cyanoacetate in 1,4-dioxane in the presence of triethylamine to produce 4H-thieno[2,3-f]chromene derivatives 10a,b. In addition, fused pyran and pyridine derivatives were synthesized starting from compound 3. The cytotoxicity of the synthesized compounds was studied on six cancer cell lines together with c-Met kinase and PC-3 cell line. The most active compounds were tested against five tyrosine kinases and Pim-1 kinase, most of which showed strong inhibition, encouraging further work.

Anti-proliferative, c-Met inhibitions and PAINS Evaluations of new Thiophene, Thiazole, Coumarin, Pyran and pyridine Derivatives

BACKGROUND

1,3-Diones are versatile reagents used for many heterocyclic transformations. Among such groups of compounds, cyclohexane-1,3-dione is widely used in organic synthesis to produce biologically active compounds.

OBJECTIVE

In this work, target molecules were synthesized from tetrahydrobenzo[b]thiophen-3- carboxamide derivative with different substituents, and their structure-activity relationships were discussed in detail.

METHOD

Cyclohexane-1,3-dione underwent different multi-component reactions to produce fused thiophene, thiazole, coumarin, pyran, and pyridine derivatives. The anti-proliferative activity of the newly synthesized compounds toward the six cancer cell lines, namely A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721 was studied. In addition, inhibitions of the most active compounds toward cancer cell lines classified according to the disease were also studied. Furthermore, Pan Assay Interference compounds (PAINS) of the selected compounds were analyzed, along with the c-Met inhibitions.

RESULTS

Anti-proliferative evaluations were performed for all of the synthesized compounds, in which the varieties of substituents through the aryl ring and the heterocyclic ring afforded compounds with high activities. Inhibition activity against the cancer cell lines classified according to the disease, c-Met, and PAINS of the synthesized compounds were measured.

CONCLUSION

Compounds 3, 13a, 13b, 14a, 16f, 17a, 28, 30a, and 31were the most cytotoxic compounds toward the six cancer cell lines. Inhibition toward cancer cell lines classified according to the disease showed that, in most cases, the presence of the electronegative CN and or Cl groups within the molecule was responsible for its high activity.

Uses of cyclohexane-1,3-dione for the synthesis of 1,2,4-triazine derivatives as anti-proliferative agents and tyrosine kinases inhibitors

Tetrahydrobenzo[b]thiophene derivatives were well known to be biologically active compounds and many of them occupy a wide range as anticancer agent drugs. One of our main aim of this work was to synthesize target molecules not only possess anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of novel 1,2,4-triazines as efficient anticancer drugs with low cytotoxicity and good bioavailability properties using cyclohexane-1,3-dione and 3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-2-diazonium chloride to give the 2-(2-(2,6-dioxocyclohexylidene)hydrazinyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (3) as the key starting material for many heterocyclization reactions. Compound 3 was reacted with phenylisothiocyanate to give the tetrahydrobenzo[e][1,2,4]triazine derivative 5 which reacted with hydrazines to give dihydrazone derivatives. In addition, it underwent multi-component reactions with aromatic aldehydes and either malononitrile or ethyl cyanoacetate in the presence of triethylamine or ammonium acetate to produce fused pyran and fused pyridine derivatives, respectively. Compounds obtained in this work were evaluated for their c-Met kinase inhibitory potency as well as in-vitro cytotoxic activity against the six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721). Molecular modeling studies were carried out for the most active compounds 5, 7a, 7b, 10c, 10e, 11c and 11f using Molecular Operating Environment (MOE) software. It was found that all the tested compounds displayed potent c-Met enzymatic activity with IC₅₀ values ranging from 0.24 to 9.36 nM. Ten of them (5, 7a, 7b, 10c, 10e, 10f, 11b, 11c, 11d and 11f) exhibited higher potency with IC₅₀ values less than 1.00 nM compared with foretinib (IC₅₀ = 1.16 nM). Also those compounds possessed moderate to strong cytotoxicity against the six tested cancer cell lines in the single-digit µM range. The synthesized compounds 5, 7a, 7b, 10c, 10e, 11c and 11f were fit on the active site of c-Met kinase, with almost the same binding pattern as foretinib and higher binding energy scores (from -16.38 to -18.21 kcal/mol) compared to foretinib (-16.37 kcal/mol). A series of novel 1,2,4-triazines were synthesized and displayed potent bioactivities, indicating that these compounds could be considered as a new lead for more investigation in the future.

Heterocyclization of 2-Arylidenecyclohexan-1,3-dione: Synthesis of Thiophene, Thiazole, and Isoxazole Derivatives with Potential Antitumor Activities

BACKGROUND

Thiophene, thiazole, and isoxazole derivatives are present in a wide range of natural and synthetic compounds with heterogeneous pharmacological activity. Due to their structural diversity, they are some of the most versatile classes of compounds for anticancer drug design and discovery.

OBJECTIVE

Thiophene, thiazole, and isoxazole derivatives were herein designed with a dual purpose: as antiproliferative agents and kinase inhibitors.

METHODS

The test compounds were synthesized in moderate to high yields through a simple methodology. Tetrahydrobenzo[b]thiophen-5-one derivatives 5a-f were prepared from the reaction of 2-arylidencyclohexan- 1,3-dione 3a-c with elemental sulfur and either of malononitrile (4a) or ethyl cyanoacetate (4b) in 1,4-dioxan in the presence of triethylamine. Compounds 5a,b were used for the synthesis of thiophene, thiazole, and isoxazole derivatives through their reactions with different chemical reagents.

RESULTS

Antiproliferative evaluations, c-Met kinase, and Pim-1 kinase inhibitions were performed where some compounds revealed high activities. In all cases, antiproliferative activity and the kinase inhibitions were performed against six cancer cell lines and five tyrosine kinases, respectively. Where the most cytotoxic compounds were 3c, 5d, and 16c with IC50's 0.29, 0.68, and 0.42μM, respectively, against the A549 cell line.

CONCLUSION

The anti-proliferative activities of the newly synthesized compounds were evaluated against the six cancer cell lines (A549, HT-29, MKN-45, U87MG, SMMC-7721, and H460). The most potent compounds toward the cancer cell lines (3a, 3c, 5d, 7c, 11c, 16a, and 16c) were further investigated towards the five tyrosine kinases (c-kit, FIT-3, VEGFR-2, EGFR, and PDGFR). Compounds 3c, 5d, and 16c were selected for testing of their inhibition for the Pim-1 kinase due to their anti-proliferation activities against the cancer cell lines and their high activities against the tyrosine kinases.

New Approaches for the Uses of Cyclohexan-1,4-dione for the Synthesis of 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-b]pyridine Derivatives used as Potential Anti-prostate Cancer Agents and Pim-1 Kinase Inhibitors

BACKGROUND

Among the wide range of heterocycles, tetrahydrobenzothienopyridine derivatives acquired a special attention due to their wide range of pharmacological activities especially the therapeutic activities. Many pharmacological drugs containing the thiophene nucleus were known in the market.

METHOD

A series of tetrahydrobenzothienopyridine derivatives were synthesized from the reaction of 2-amino- 3-benzoyl-4,5-dihydrobenzo[b]thiophen-6(7H)-one, synthesized and used for further heterocyclization reactions through reaction with different reagents.

RESULTS

Antiproliferative evaluations and c-Met kinase, Pim-1 kinase inhibitions were performed where some compounds revealed high activities.

CONCLUSION

The inhibition of the newly synthesized compounds towards c-Met kinase, the five c-Metdependent cancer cell lines (A549, HT-29, MKN-45, U87MG, and SMMC-7721) and one c-Met-independent cancer cell line (H460) were investigated using foretinib as a standard drug. The results showed that compounds 6b, 7e, 9b, 9e, 16c and 20d were more active than foretinib. Furthermore, compounds 6b, 13b, 16b and 16c were selected to examine their Pim-1 kinase inhibition activity, where compounds 16b and 16c were of high potencies with IC50 values of 0.28 and 0.32 µM, while compounds 6b and 13b were less effective (IC50 > 10 µM).

Cytotoxicity and Anti-proliferative Properties of Heterocyclic Compounds Derived from Progesterone

The following study explored the cytotoxic effect on human cancer cells of a series of novel progesterone derivatives through the synthesis of heterocyclic compounds incorporating progesterone moiety. The reaction of progesterone (1) with cyanoacetanilide derivatives gave the condensation products 3a,b. Either of compound 3a or 3b reacted with elemental sulfur affording the thiophene derivatives 4a and 4b, respectively. In addition, progesterone (1) underwent some multi-component reactions with aromatic aldehydes and cyanomethylene reagents in triethylamine to give the pyran derivatives 10a-f. Carrying the same reactions but using ammonium acetate afforded the pyridine derivatives 11a-f. The anti-tumor evaluations of the newly synthesized products were tested against six human cancer and normal cell lines. The results showed that nine compounds (3b, 7c, 10b, 10d, 10f, 11d, 13a, 13b and 14b) revealed optimal cytotoxic effect against cancer cell lines with IC50 ˂ 550 nM and their cytotoxicity's were higher than that of progesterone. Moreover, the toxicity of the most active compounds was measured against shrimp larvae. In addition, the anti-proliferative evaluations of these potent compounds were measured.

Synthesis and antitumor evaluation of novel dihydropyrimidine, thiazolo[3,2-a]pyrimidine and pyrano[2,3-d]pyrimidine derivatives

A simple and efficient method has been developed for the synthesis of 4,5-dihydro-2-mercapto-4-oxo-6-substituted arylpyrimidine derivatives (2a-e) and their fused rings (3b, 4b, 5b & 6b) and also 1,4-dihydro-2-mercaptopyrimidine derivatives (7a-e) & (9a-e) using triethylamine as a catalyst. The structure of the newly synthesized compounds was confirmed on the basis of their spectral data and elemental analysis. All the synthesized compounds were evaluated for their in vitro anticancer activity against six human cancer cell lines and normal fibroblasts. Thirteen of the tested compounds: 2a-e, 3b, 4b, 5b, 7d, 8, 9a, 9c and 9d exhibited significant cytotoxicity against most cell lines. Among these derivatives compounds 2a, 3b and 9c are the most potent, they exhibited cytotoxic effect against the six cancer cell lines with IC(50) values < 330 nM compared to the standard CHS 828. Normal fibroblast cells (WI38) were affected to a much lesser extent (IC(50) >10,000 nM).