ABSTRACT
We have synthesized a series of novel coumarin-steroid and triterpenoid hybrids and evaluated their potential anticancer activity through molecular docking calculations and inâ vitro antiproliferative assays. These hybrids, derived from estrone and oleanolic acid, were linked via hydrocarbon spacers of varying lengths. Molecular docking studies against human aromatase revealed strong interactions, particularly for compound 11d, which exhibited significant binding affinity (-12.6308â kcal/mol). In vitro assays demonstrated that compounds 6b and 11d had notable antiproliferative effects, with GI50 values of 5.4 and 7.0â µM against WiDr (colon) and HeLa (cervix) cancer cells, respectively. These findings highlight the potential of these hybrids as novel anticancer agents targeting aromatase, warranting further investigation and optimization.
ABSTRACT
The involvement of carbonic anhydrases (CAs) in a myriad of biological events makes the development of new inhibitors of these metalloenzymes a hot topic in current Medicinal Chemistry. In particular, CA IX and XII are membrane-bound enzymes, responsible for tumour survival and chemoresistance. Herein, a bicyclic carbohydrate-based hydrophilic tail (imidazolidine-2-thione) has been appended to a CA-targeting pharmacophore (arylsulfonamide, coumarin) with the aim of studying the influence of the conformational restriction of the tail on the CA inhibition. For this purpose, the coupling of sulfonamido- or coumarin-based isothiocyanates with reducing 2-aminosugars, followed by the sequential acid-promoted intramolecular cyclization of the corresponding thiourea and dehydration reactions, afforded the corresponding bicyclic imidazoline-2-thiones in good overall yield. The effects of the carbohydrate configuration, the position of the sulfonamido motif on the aryl fragment, and the tether length and substitution pattern on the coumarin were analysed in the in vitro inhibition of human CAs. Regarding sulfonamido-based inhibitors, the best template turned out to be a d-galacto-configured carbohydrate residue, meta-substitution on the aryl moiety (9b), with Ki against CA XII within the low nM range (5.1 nM), and remarkable selectivity indexes (1531 for CA I and 181.9 for CA II); this provided an enhanced profile in terms of potency and selectivity compared to more flexible linear thioureas 1-4 and the drug acetazolamide (AAZ), used herein as a reference compound. For coumarins, the strongest activities were found for substituents devoid of steric hindrance (Me, Cl), and short linkages; derivatives 24h and 24a were found to be the most potent inhibitors against CA IX and XII, respectively (Ki = 6.8, 10.1 nM), and also endowed with outstanding selectivity (Ki > 100 µM against CA I, II, as off-target enzymes). Docking simulations were conducted on 9b and 24h to gain more insight into the key inhibitor-enzyme interactions.
Subject(s)
Carbonic Anhydrases , Neoplasms , Humans , Molecular Structure , Carbonic Anhydrase Inhibitors/pharmacology , Carbonic Anhydrase Inhibitors/chemistry , Structure-Activity Relationship , Carbonic Anhydrase IX/metabolism , Carbonic Anhydrases/metabolism , Antigens, Neoplasm , Coumarins/pharmacology , Coumarins/chemistry , Glycoconjugates , CarbohydratesABSTRACT
Estrogens play a pivotal role in the development of estrogen-dependent breast cancer and other hormone-dependent disorders. A common strategy to overcome the pathological effects of estrogens is the use of aromatase inhibitors (AIs), which bind to the enzyme and prevent the union with the natural substrate, decreasing the amount of estrogens produced. Several AIs have been developed, including inhibitors with a steroidal backbone and a nitrogen heterocycle in their structure. Encouraged by the notable results presented by current and clinical steroidal drugs, herein we present the synthesis of a steroidal spiro morpholinone derivative as a plausible aromatase inhibitor. The morpholinone derivative was synthesized over a six-step methodology starting from estrone. The title compound and its hydroxychloroacetamide derivative precursor were evaluated for their antiproliferative profile against estrogen-dependent and independent solid tumor cell lines: A549, HBL-100, HeLa, SW1573, T-47D and WiDr. Both compounds exhibited a potent antiproliferative activity in the micromolar range against the six cancer cell lines, with the hydroxychloroacetamide derivative precursor being a more potent inhibitor (GI50 = 0.25-2.4 µM) than the morpholinone derivative (GI50 = 2.0-11 µM). Furthermore, both compounds showed, in almost all cases, better GI50 values than the steroidal anticancer drugs abiraterone and galeterone. Docking simulations of the derivatives were performed in order to explain the experimental biological activity. The results showed interactions with the iron heme (derivative 3) and important residues of the steroidal binding-site (Met374) for the inhibition of human aromatase. A correlation was found between in vitro assays and the score obtained from the molecular docking study.
Subject(s)
Antineoplastic Agents , Breast Neoplasms , Female , Humans , Antineoplastic Agents/chemistry , Aromatase Inhibitors/chemistry , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation , Estrogens/pharmacology , Estrone/pharmacology , Molecular Docking Simulation , Molecular Structure , Structure-Activity Relationship , Morpholines/chemical synthesis , Morpholines/pharmacologyABSTRACT
A small and focused library of steroidal non-fused and fused pyrimidines was prepared from pregnenolone acetate and diosgenin, respectively. The key step was the cycloaddition reaction of nitrogen-containing 1,3-binucleophiles with the steroidal α,ß-unsaturated ketone. Urea, thiourea and guanidine reacted in a similar manner and afforded the steroidal pyrimidines in good yields. The antiproliferative tests against human tumor cell lines gave GI50 values in the micromolar range and had no effect on healthy fibroblasts. Additional experiments indicated that the compounds did not act as P-glycoprotein substrates, thus avoiding the rise of drug resistance. The fused steroidal pyrimidinethione was selected as drug lead for further testing due to its strong antiproliferative activities within the low micromolar range.
Subject(s)
Cell Proliferation/drug effects , Neoplasms/drug therapy , Pyrimidines/pharmacology , Steroids/pharmacology , Acetates/chemistry , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Nitrogen/chemistry , Pregnenolone/chemistry , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Steroids/chemical synthesis , Steroids/chemistry , Structure-Activity RelationshipABSTRACT
Herein we report the straightforward preparation of novel conformationally-restricted steroids from trans-androsterone and estrone, decorated with spiranic oxazolidin-2-one or 2-aminooxazoline motifs at C-17 as potential antiproliferative agents. Such unprecedented pharmacophores were accessed using an aminomethylalcohol derivative at C-17 as the key intermediate; reaction of such functionality with triphosgene, or conversion into N-substituted thioureas, followed by an intramolecular cyclodesulfurization reaction promoted by yellow HgO, furnished such spirocycles in excellent yields. Title compounds were tested in vitro against a panel of six human tumor cell lines, named A549 (non-small cell lung), HBL-100 (breast), HeLa (cervix), SW1573 (non-small cell lung), T-47D (breast) and WiDr (colon), and the results were compared with steroidal chemotherapeutic agents (abiraterone and galeterone); the A-ring of the steroidal backbone, the nature of the heterocycle and the N-substituents proved to be essential motifs for establishing structure-activity relationships concerning not only the potency but also the selectivity against tumor cell lines. Estrone derivatives, particularly those bearing a spiranic 2-aminooxazoline scaffold were found to be the most active compounds, with GI50 values ranging from the low micromolar to the submicromolar level (0.34-1.5 µM). Noteworthy, the lead compounds showed a remarkable increase in activity against the resistant cancer cell lines (T-47D and WiDr) compared to the anticancer reference drugs (up to 120-fold).
Subject(s)
Antineoplastic Agents/pharmacology , Heterocyclic Compounds/pharmacology , Spiro Compounds/pharmacology , Steroids/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Heterocyclic Compounds/chemical synthesis , Heterocyclic Compounds/chemistry , Humans , Models, Molecular , Molecular Structure , Spiro Compounds/chemical synthesis , Spiro Compounds/chemistry , Steroids/chemical synthesis , Steroids/chemistry , Structure-Activity RelationshipABSTRACT
Starting from natural steroids (diosgenin, hecogenin, smilagenin, estrone), we have prepared a wide panel of selenoderivatives, including benzoselenazolones, selenosemicarbazones, isoselenocyanates, selenoureas, selenocyanates and diselenides, with the aim of developing new families of potential chemotherapeutic agents. The modification of the organoselenium moieties, and their position on the steroid provided valuable information concerning the antiproliferative activities. Among all the families accessed herein, the best profile was achieved for selenoureas on the A ring of estrone, which exhibited GI50 values in the range 2.0-4.1 µM for all the tested tumor cell lines, with increased potency compared with commonly used chemotherapeutic agents, like 5-fluorouracil and cisplatin. Cell cycle analysis revealed that selenoureas induced accumulation of cells in the G1 phase of the cell cycle in the breast cancer cell lines HBL-100 and T-47D; therefore, a different mechanism than cisplatin, that induces cell cycle accumulation in the S phase as a result of DNA damage, must be involved. In the rest of the tumor cells, a slight increase of the S compartment was observed. Moreover, selenosteoids turned out to be excellent glutathione peroxidase (GPx) mimics for the catalytic removal of deleterious H2O2 (t1/2 8.0-22.5 min) and alkyl peroxides (t1/2 23.0-38.9 min) when used in substoichiometric amounts (1% molar ratio), thus providing a valuable tool for reducing the intrinsic oxidative stress in tumor progression.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Organoselenium Compounds/chemistry , Organoselenium Compounds/pharmacology , Steroids/chemistry , Biphenyl Compounds/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Hydrogen Peroxide/chemistry , Picrates/chemistryABSTRACT
A novel three-step methodology to obtain 6a-aza-B-homo steroidal lactams has been developed starting from the easily available cholesterol and pregnenolone. In addition, a new procedure for the synthesis of a 6a-aza-B-homo steroidal lactam analog of vespertilin, starting from diosgenin has been established. In both synthetic pathways, the key intermediate is a hydroxyimino derivative obtained in a one- or two-step sequence from the starting materials. These methods avoid the use of hazardous oxidant agents in the process. The new steroidal oximes and lactams were examined for their antiproliferative activities against several tumor cell lines. The 6,23-dihydroxyimino derivative exhibited the highest activity with GI50 values of 11-22µM.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Lactams/chemistry , Oximes/chemistry , Steroids/chemical synthesis , Steroids/pharmacology , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Chemistry Techniques, Synthetic , Humans , Models, Molecular , Molecular Conformation , Steroids/chemistryABSTRACT
The synthesis of several monomeric and dimeric steroidal [1,2,4]triazolo[1,5-a]pyrimidines (TPs) derived from steroids are described. These derivatives were prepared from α,ß-unsaturated carbonyl compounds through a Claisen Schmidt condensation and rearrangement of the spiro moiety followed by a cycloaddition with 3-amino-1,2,4-triazole. The antiproliferative activity of compounds 7, 13-15 was tested against human cancer cells; several IG50 values were below 10µM.
Subject(s)
Pyrimidines/chemistry , Steroids/chemical synthesis , Triazoles/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Stereoisomerism , Steroids/chemistry , Steroids/pharmacologyABSTRACT
The stereoselective preparation of diosgenin-derived thio(seleno)ureas and glycomimetics bearing a 1,2,3-triazolyl tether on C-3 has been accomplished. The key steps in the synthetic pathway are the incorporation of an amino moiety and its further transformation into thio- and selenoureas, and also a click chemistry reaction involving a propargyl residue and an azido moiety to afford carbohydrate-derived 1,2,3-triazoles; subsequent BF3-promoted acetolysis of the spiranic moiety afforded the corresponding 22-oxocholestanic structure. The N-phenyl selenourea, an hitherto unknown steroidal derivative, turned out to be a potent ROS scavenger, in particular against free radicals (EC50 = 29.47 ± 2.33 µM, DPPH method), and as a glutathione peroxidase mimic in the elimination of H2O2 (t1/2 = 4.8 min, 1% molar ratio). 22-Oxocholestane structures bearing a C-3 azido, propargyl, thioureido, and particularly selenoureido moiety behaved as strong antiproliferative agents against HeLa cells (IC50 1.87-11.80 µM). N-phenyl selenourea also exhibited IC50 values lower than 6.50 µM for MDA-MB-231, MCF-7 and HepG2 cancer cells; apoptosis was found to be involved in its mode of action. Such compound was also capable of efficiently eliminating ROS endogenously produced by HeLa cells. Antiproliferative properties of thioxo and selenoxo derivatives were stronger than diosgenin.
Subject(s)
Diosgenin/chemistry , Diosgenin/pharmacology , Drug Design , Glycoconjugates/chemistry , Glycoconjugates/pharmacology , Organoselenium Compounds/chemistry , Triazoles/chemistry , Urea/analogs & derivatives , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Biomimetic Materials/chemistry , Biomimetic Materials/metabolism , Biomimetic Materials/pharmacology , Biphenyl Compounds/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Diosgenin/metabolism , Drug Screening Assays, Antitumor , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Glutathione Peroxidase/metabolism , Glycoconjugates/metabolism , Humans , Mice , Picrates/metabolism , Reactive Oxygen Species/metabolism , Urea/chemistryABSTRACT
Most of the naturally occurring steroidal sapogenins (C-23 non-substituted frameworks), possess an R configuration at the spiro C-22 center. Their C-22 epimers have become important targets in biological research. This paper describes a procedure to obtain 22S-spirostans from 22R-sapogenins and pseudosapogenin skeletons, without affecting the chirality at either C-25 or C-20. An optimal way to synthesize the pair of C-22 stereoisomers of 23-acetyldiosgenin is also reported. The latter was obtained from a 22,26-epoxycholestane or from 23-acetylfurostene compounds.
Subject(s)
Sapogenins/chemistry , Magnetic Resonance Spectroscopy , Molecular Conformation , StereoisomerismABSTRACT
An efficient and facile synthesis of fused, substituted and spiro pyrazoline steroid derivatives through a cycloaddition reaction of different α,ß-unsaturated ketones with hydrazine acetate in acetic acid is reported. Depending on the starting material, the ring closure reaction provided a mixture of two steroidal pyrazoline epimers that were separated and studied by NMR techniques. In one case it was possible to isolate and characterize the hydrazone derivative as the reaction intermediate, which confirms the mechanism proposed in the literature [11,25,26].