Design and synthesis of novel D-ring fused steroidal heterocycles

Synthesis, biological activities, and future perspectives of steroidal monocyclic pyridines

Steroidal pyridines are a class of compounds that have been the subject of extensive research in recent years due to their potential biological activities. The introduction of a pyridine ring into the steroid skeleton can significantly alter the chemical and biological properties of the compound, making it more potent and/or selective for a particular target. Different synthetic methods have been developed for the preparation of steroidal pyridines. This review provides an overview of the synthesis, biological activities, and future perspectives of steroidal monocyclic dihydropyridines, tetrahydropyridines, and pyridines from 2005 to the present. The different synthetic methods that have been developed for the preparation of these steroids are discussed, as well as the proposed mechanisms and the biological activities that have been reported. Finally, the potential of steroidal monocyclic pyridines for the development of new drugs is discussed. This review is intended to provide a comprehensive overview of the field of steroidal monocyclic pyridines for researchers and scientists who are interested in this area of research. It is also hoped that this review will stimulate further research into the synthesis and biological activities of steroidal pyridines to develop new and improved drugs for the treatment of diseases.

Synthesis, antifungal evaluation, and molecular docking studies of steroidal thiazolopyrimidines

A series of steroidal thiazolopyrimidine derivatives were developed and evaluated for their antifungal properties against Candida species using steroid as the basic skeletonand a thiazolopyrimidine heterocycle as a pharmacophore in the D-ring. Dehydroepiandrosterone, aromatic aldehydes, and 2-aminothiazole were used in a one-pot multicomponent reaction with silica sulphuric acid to generate the target molecules. Additionally, molecular docking studies were conducted to determine how synthesized steroidal derivatives interacted with the amino acid residues of CYP51 ofCandida albicans.

Synthesis and biological evaluation of 17-cyanopyridine derivatives of pregnenolone as potential anti-prostate cancer agents

A series of new 17-cyanopyridine derivatives of pregnenolone have been synthesized, and their anti-proliferative activities against different human cancer cell lines were tested. The extensive structure-activity relationship (SAR) data suggested that the introduction of 2-amino-4-aryl-3-cyanopyridine to the D ring of pregnenolone may increase the anti-cancer activity. Among the products, the most potent compound 4j exhibited good growth inhibition against all the tested cells especially for PC- 3 cells with an IC50 value of 2.0 μM. Further mechanistic studies showed that 4j inhibited the formation of cell colonies and migration, increased the level of reactive oxygen species (ROS) in PC-3 cells in a concentration-dependent manner, and induced necroptosis through the phosphorylation of receptor interacting protein 1/3 (P-RIP1/3) and phosphorylation of mixed lineage kinase domain-like protein (P-MLKL) pathway. The 17-pregnenolone cyanopyridine derivatives hold promising potential as anti-proliferative agents, and the most potent compound could be used as a starting point for the development of new steroidal heterocycles with improved anticancer potency and selectivity.

Design, Synthesis and Biological Evaluation of Steroidal Glycoconjugates as Potential Antiproliferative Agents

To systematically evaluate the impact of neoglycosylation upon the anticancer activities and selectivity of steroids, four series of neoglycosides of diosgenin, pregnenolone, dehydroepiandrosterone and estrone were designed and synthesized according to the neoglycosylation approach. The structures of all the products were elucidated by NMR analysis, and the stereochemistry of C20-MeON-pregnenolone was confirmed by crystal X-ray diffraction. The compounds' cytotoxicity on five human cancer cell lines was evaluated using a Cell Counting Kit-8 assay, and structure-activity relationships (SAR) are discussed. 2-deoxy-d-glucoside 5 k displayed the most potent antiproliferative activities against HepG2 cells with an IC₅₀ value of 1.5 μM. Further pharmacological experiments on compound 5 k on HepG2 cells revealed that it could cause morphological changes and cell-cycle arrest at the G0/G1 phase and then induced the apoptosis, which might be associated with the enhanced expression of high-mobility group Box 1 (HMGB1). Taken together, these findings prove that the neoglycosylation of steroids could be a promising strategy for the discovery of potential antiproliferative agents.

Multi-Component One-Pot Assisted Synthesis, Anti-bacterial Capabilities, and Scanning Electron Microscopy of Novel Corticosteroid Thiopyran

BACKGROUND

Corticosteroids are an important group of polycyclic compounds having a wide range of pharmacological and physiological properties. Thiopyran derivatives are important building blocks of many biologically active compounds.

OBJECTIVE

Keeping in mind the wide range of applications of corticosteroids and thiopyran, herein we intend to develop a simple and efficient strategy to synthesize steroidal thiopyran derivatives starting with different commercially available corticosteroids and study their biological properties.

MATERIALS AND METHODS

To achieve our aim, we employed a one-pot multi-component synthesis of steroidal thiopyran derivatives by the reaction of corticosteroids, malononitrile, and carbon disulphide in the presence of triethylamine as a catalyst.

RESULTS AND DISCUSSION

An array of novel thiopyran compounds was obtained with the highest product yield using Et₃N. Scanning electron microscopy analysis manifested agglomeration pertaining to brick-shaped crystals of corticosteroid thiopyran. Synthesized compounds were also found to be active as anti-bacterial agents.

CONCLUSION

We describe a facile one-pot multi-component synthesis of corticosteroid thiopyran derivatives, which are found to possess anti-bacterial activity. Excellent yields of the products, simple work-up, easily available starting materials, and non-chromatographic purification are some of the main advantages of this protocol.

Multistep Synthesis and In Vitro Anticancer Evaluation of 2-Pyrazolyl-Estradiol Derivatives, Pyrazolocoumarin-Estradiol Hybrids and Analogous Compounds

Although the hormone independent cytotoxic activity of several estradiol derivatives endowed with a simple substituent at C-2 has been reported so far, 2-heterocyclic and 2,3-condensed analogs are less investigated from both synthetic and pharmacological points of view. Therefore, novel A-ring-connected 2-pyrazoles of estradiol and, for comparison, their structurally simplified non-steroidal pairs were synthesized from estradiol 3-methyl ether and 6-methoxy-1,2,3,4-tetrahydronaphthalene. Friedel-Crafts acetylation of the protected phenolic compounds and subsequent O-demethylation led to ortho-substituted derivatives regioselectively, which were converted to arylhydrazones with phenylhydrazine, 4-tolylhydrazine and 4-chloro-phenylhydrazine, respectively, under microwave conditions. The hydrazones were subjected to cyclization with the Vilsmeier-Haack reagent immediately after preparation and the ring closure/formylation sequence resulted in steroidal and non-steroidal 4'-formylpyrazoles in moderate to good yields. During reductive transformations, 4-hydroxymethyl-pyrazoles were obtained, while oxidative lactonization of the 4-formylpyrazole moiety with the phenolic OH in the presence of the Jones reagent afforded A-ring-integrated pyrazolocoumarin hybrids and related analogs. Steroidal pyrazoles, which were produced as C-17 acetates due to acetylation of C-17 OH during the primary Friedel-Crafts reaction, underwent deacetylation in alkaline methanol to furnish 2-heterocyclic estradiol derivatives. Pharmacological studies revealed the overall and cancer cell-specific cytotoxicity of the derivatives and the half maximal inhibitory concentrations were obtained for the most promising compounds.

Microwave-Induced Ugi-Four Component Reactions: Synthesis of New Hetero- Steroid-Amino Acid Conjugates

BACKGROUND

Aza-steroids are an important class of compounds because of their numerous biological activities. The hetero steroids have different hydrogen bonding ability and hydrophobicity in comparison to steroids.

MATERIALS AND METHODS

Microwave-induced synthesis of a novel type of hybrid hetero-steroid amine conjugates, following Ugi-four component reactions of steroidal amines with alanine and valine methyl esters as amino acid residues is described. Specifically, hetero-steroid-amino acid conjugate based on D-ring fused hetero steroidal amine, hetero-steroid-amino acid conjugate based on A-ring hetero steroidal amine, and hetero-steroidamino acid conjugate based on B-ring hetero steroidal amine are synthesized.

RESULTS AND DISCUSSION

The yield of the products under microwave-induced process was considerably higher than that obtained by the conventional method. In contrast to the conventional method for the synthesis of these molecules, microwave-induced method has several advantages.

CONCLUSION

These include rapid reaction, a superior yield of the product, minimum side reaction, and economical microwave-induced process.

Synthesis and antiproliferative activity of novel 4-azasteroidal-17-hydrazone derivatives

A new series of 4-azasteroidal-17-hydrazone derivatives have been synthesized from androstenedione. Their structures were characterized by analysis and spectroscopic data. The antiproliferative activity of synthesized compounds against three cancer cells (human lung adenocarcinoma, human oesophageal cervical cancer, human gastric adenocarcinoma) and a normal cell line (human gastric mucosal) was investigated. The studies show that the compound bearing a naphthyl group displayed the same antiproliferative activity in vitro against tested cells as cis-platin did (a positive control). Most of the compounds show very weak toxicity towards normal human gastric mucosal cell line.

Steroidal dimer by001 inhibits proliferation and migration of esophageal cancer cells via multiple mechanisms

OBJECTIVE

To investigate the potential inhibitory effects of structurally novel steroidal dimer by001 in esophageal cancer in vitro.

METHODS

The cytotoxicity of by001 on esophageal, gastric, neuroblastoma and prostate cancer cells was examined MTT assay and colony formation assay. By001 induced apoptosis and production of intracellular reactive oxygen species on esophageal cancer cells Ec109, TE-1 and human normal gastric epithelial cells GES-1 was detected by flow cytometry. The effect of by001 on mitochondrial membrane potential was detected by fluorescence microscope through JC-1 staining. The level of intracellular reactive oxygen species was measured by fluorescence microscope and flow cytometry via DCFH-DA staining. The effect of by001 on members of Bcl-2 family, Fas, LC3, PARP and caspases was determined by Western blot. The effect of by001 on migration was measured by transwell assay.

RESULTS

By001 effectively inhibited proliferation of esophageal, gastric, neuroblastoma and prostate cancer cells in a time- and concentration-dependent manner in vitro. By001 reduced the number and the size of colonies at low micromolar concentrations, elevated cellular ROS levels and caused mitochondrial dysfunction in esophageal cancer cells. Molecular mechanistic studies showed that by001 triggered apoptosis through regulating members of Bcl-2 family and Fas.

CONCLUSIONS

These findings suggested that by001 may inhibited proliferation of esophageal cancer cells through mitochondria and death receptor-mediated apoptotic pathways, autophagy induction, as well as suppressed migration of esophageal cancer cells.

Facile one-pot multicomponent synthesis and molecular docking studies of steroidal oxazole/thiazole derivatives with effective antimicrobial, antibiofilm and hemolytic properties

A series of steroidal oxazole and thiazole derivatives have been synthesized employing thiosemicarbazide/semicarbazide hydrochloride and ethyl 2-chloroacetoacetate with a simple and facile one-pot multicomponent reaction pathway. The antimicrobial activity of newly synthesized compounds were evaluated against four bacterial strains namely Gram-negative (Escherichia coliand Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) in addition to pathogenic fungi (Candida albicans and Cryptococcus neoformans). Bioactivity assay manifested that most of the compounds exhibited good antimicrobial activity. To provide additional insight into antimicrobial activity, the compounds were also tested for their antibiofilm activity against S. aureus biofilm. Moreover, molecular docking study shows binding of compounds with amino acid residues of DNA gyrase and glucosamine-6-phosphate synthase (promising antimicrobial target) through hydrogen bonding interactions. Hemolytic activity have been also investigated to ascertain the effect of compounds over RBC lysis and results indicate good prospects for biocompatibility. The expedient synthesis of steroidal heterocycles, effective antibacterial and antifungal behavior against various clinically relevant human pathogens, promising biocompatibility offer opportunities for further modification and potential applications as therapeutic agents.

Microwave-assisted MgO NP catalyzed one-pot multicomponent synthesis of polysubstituted steroidal pyridines

MgO NPs were proved to be a highly efficient catalyst for mild and clean conversion of steroids to steroidal heterocycles.

Amphiphilic derivatives of (3β,17β)-3-hydroxyandrost-5-ene-17-carboxylic acid

A series of amphiphilic derivatives of (3β,17β)-3-hydroxyandrost-5-ene-17-carboxylic acid (1) with the polyamine spermine and three other diamines, 1,2-diaminoethane, piperazine and cadaverine, were synthesized and their antimicrobial activity and cytotoxicity were investigated. Among the target compounds, several ones showed antimicrobial activity on Gram positive and Gram negative microorganisms. The most active compounds were 20 (Streptococcus mutans CCM 7409, 3.125 µM), 16 (Streptococcus mutans CCM 7409, 12.5 µM) and 10d (Escherichia coli CCM 3954, 12.5 µM). In addition, compounds 5d, 10d, 13 and 20 displayed cytotoxicity on CEM (12.1 ± 2.1 µM, 7.6 ± 1.0 µM, 19.0 ± 0.4 µM and 5.9 ± 0.7 µM, respectively). Two additional compounds displayed medium cytotoxicity on CEM, 5a (34.6 ± 5.2 µM) and 5c (37.7 ± 5.9 µM). The compound 13 and 20 displayed high toxicity also on normal fibroblasts.

Synthesis, Characterization, and Evaluation of Cytotoxic Effects of Novel Hybrid Steroidal Heterocycles as PEG Based Nanoparticles

Anticancer agents featuring hybrid molecules can improve effectiveness and diminish drug resistance. The current study aimed to introduce newly synthesized heterocyclic steroids of promising anticancer effects loaded in polyethylene glycol (PEG)•based nanoparticles form. Several heterocyclic steroids (1-9) were synthesized via multicomponent reactions (MCRs) and confirmed via the analytical and spectral data. Compounds 1, 2, 3, 4, 5, 6, 7 and 9, were investigated individually in their free and PEG based nano-size hybrid forms as anticancer agents against three human cell lines: hepatocellular carcinoma cells (HepG2); breast cancer cells (MCF-7); and colon cancer cells (HCT116). The neutral red supravital dye uptake assay was employed. Compound 6 in its PEG based nano-size form exhibited the best cytotoxic effects against HepG2 and HCT116 cell lines, with IC50 values of 2.44 μmol/l and 2.59 μmol/l, respectively. In addition, it demonstrated a low IC50 value against MCF-7 (3.46μmol/l) cells. This study introduced promising anticancer agents acting through conversion into PEG-based nanoparticles.

Synthesis and biological evaluation of novel steroidal 5α,8α-epidioxyandrost-6-ene-3β-ol-17-(O-phenylacetamide)oxime derivatives as potential anticancer agents

Inspired by the significant anti-cancer activity of our previously screened natural ergosterol peroxide (EP, 1), we synthesized and characterized a series of novel 5α,8α-epidioxyandrost-3β-ol-17-(O-phenylacetamide)oxime derivatives (9a-o). The anti-proliferative activity of the synthesized compounds against human hepatocellular carcinoma cells (HepG2, Sk-Hep1) and human breast cancer cells (MCF-7, MDA-MB231) were investigated. Compounds 9d, 9f, 9h, 9j and 9m displayed good anti-proliferative activity (most IC₅₀<20μM) in vitro. Furthermore, fluorescence imaging showed that the designed coumarin-9d conjugate (12) localized mainly in mitochondria, leading to enhanced anticancer activities over the parent structure.

Synthesis of 5α,8α-Ergosterol Peroxide 3-Carbamate Derivatives and a Fluorescent Mitochondria-Targeting Conjugate for Enhanced Anticancer Activities

Inspired by the significant anticancer activity of our previously screened natural ergosterol peroxide (1), we synthesized and characterized a series of novel ergosterol peroxide 3-carbamate derivatives. The antiproliferative activities of the synthesized compounds against human hepatocellular carcinoma cells (HepG2, SK-Hep1) and human breast cancer cells (MCF-7, MDA-MB231) were investigated. 5α,8α-Epidioxyergosta-3-yl-(piperazine-1)carbamate (3 d) and 5α,8α-epidioxyergosta-3-yl-(piperidin-4-methylamine)carbamate (3 f) and their hydrochloride salts exhibited significant in vitro antiproliferative activities against the tested tumor cell lines, with IC₅₀ values ranging from 0.85 to 4.62 μm. Furthermore, fluorescent imaging showed that the designed coumarin-3 d conjugate (5) localized mainly in mitochondria, leading to enhanced anticancer activities over the parent structure 1. As a whole, it appeared that substituent changes at the C3 position could serve as a promising launch point for further design of this type of steroidal anticancer agent.

Synthesis and Cytotoxic Activity of Triterpenoid Thiazoles Derived from Allobetulin, Methyl Betulonate, Methyl Oleanonate, and Oleanonic Acid

A total of 41 new triterpenoids were prepared from allobetulone, methyl betulonate, methyl oleanonate, and oleanonic acid to study their influence on cancer cells. Each 3-oxotriterpene was brominated at C2 and substituted with thiocyanate; subsequent cyclization with the appropriate ammonium salts gave N-substituted thiazoles. All compounds were tested for their in vitro cytotoxic activity on eight cancer cell lines and two non-cancer fibroblasts. 2-Bromoallobetulone (2 b) methyl 2-bromobetulonate (3 b), 2-bromooleanonic acid (5 b), and 2-thiocyanooleanonic acid (5 c) were best, with IC₅₀ values less than 10 μm against CCRF-CEM cells (e.g., 3 b: IC₅₀ =2.9 μm) as well as 2'-(diethylamino)olean-12(13)-eno[2,3-d]thiazole-28-oic acid (5 f, IC₅₀ =9.7 μm) and 2'-(N-methylpiperazino)olean-12(13)-eno[2,3-d]thiazole-28-oic acid (5 k, IC₅₀ =11.4 μm). Compound 5 c leads to the accumulation of cells in the G₂ phase of the cell cycle and inhibits RNA and DNA synthesis significantly at 1×IC₅₀ . The G₂ /M cell-cycle arrest probably corresponds to the inhibition of DNA/RNA synthesis, similar to the mechanism of action of actinomycin D. Compound 5 c is new, active, and nontoxic; it is therefore the most promising compound in this series for future drug development. Methyl 2-bromobetulonate (3 b) and methyl 2-thiocyanometulonate (3 c) were found to inhibit nucleic acid synthesis only at 5×IC₅₀ . We assume that in 3 b and 3 c (unlike in 5 c), DNA/RNA inhibition is a nonspecific event, and an unknown primary cytotoxic target is activated at 1×IC₅₀ or lower concentration.

Structurally novel steroidal spirooxindole by241 potently inhibits tumor growth mainly through ROS-mediated mechanisms

Cancer cells always have increased ROS levels, thus making them more vulnerable to persistent endogenous oxidative stress. The biochemical difference between cancer and normal cells could be exploited to achieve selective cancer cell killing by exogenous ROS-producing agents. Herein we described a structurally novel steroidal spirooxindole by241 and its anticancer efficacy. By241 exhibited potent inhibition against human cancer cells and less toxic to normal cells. By241 concentration-dependently induced apoptosis of MGC-803 and EC9706 cells, accompanied with the mitochondrial dysfunction and increased ROS levels. NAC can completely restore the decreased cell viability of MGC-803 cells caused by by241, suggesting ROS-mediated mechanisms. The expression levels of proteins involved in the mitochondrion-related pathways were detected, showing increased expression of proapoptotic proteins and decreased expression of anti-apoptotic proteins, and activation of caspases-9/-3, but without activating caspase-8 expression. Pretreatment with Z-VAD-FMK partially rescued by241-induced apoptosis of MGC-803 cells. Additionally, by241 inhibited mTOR, activated p53 and its downstream proteins, cleaved MDM2 and PI3K/AKT as well as NF-κB signaling pathway. In vivo experiments showed that by241 did not have significant acute oral toxicity and exerted good anticancer efficacy against MGC-803 bearing mice models. Therefore, by241 may serve as a lead for further development for cancer therapy.

Synthesis and antiproliferative activity of D-ring substituted steroidal benzamidothiazoles

Using progesterone as the starting material, we synthesized a series of steroidal derivatives possessing a D-ring substituted benzamidothiazole. All of the final structures were reported and identified by NMR and HRMS spectrometry for the first time. The antiproliferative activity of the synthesized compounds against PC-3 (human prostate cancer cell line) and SKOV-3 (ovarian cancer cells) were investigated. The preliminary results showed that compounds 8b, 8d and 8g possessed moderate antiproliferative activities.

Synthesis and biological evaluation of 3β-androsta-5,8(14),15-trien-17-one derivatives as potential anticancer agents

A novel and operationally simple method for highly efficient synthesis of promising anti-cancer 3β-hydroxy-16-arylandrosta-5,8(14),15-trien-17-ones was reported. Compounds were tested for their cytotoxic activities against A549, SKOV3, MKN-45 and MDA-MB-435 cancer cell lines. The preliminary results showed that compounds 5e, g were the most active especially against cancer cell lines tested.

Green Suzuki Coupling Reaction for Synthesis of Abiraterone Acetate and its Analogues

An eco-friendly efficient method was developed for the synthesis of abiraterone acetate and analogues in water-PEG-400 (6:1; v/v) at 75°C from various arylboronic acids and 17-(trifluoromethanesulfonyl)oxy-3β-acetoxylandrosta-5,16-diene obtained from the 3-acetate of dehydroepiandrosterone.

Multicomponent assembly of novel antiproliferative steroidal dihydropyridinyl spirooxindoles

Multicomponent assembly of steroidal dihydropyridinyl spirooxindoles from pregnenolone, isatins, malononitrile, and ammonium acetate is described, which involves the formation of two C-C bonds, two C-N bonds, and an all-carbon quaternary stereogenic center in a single operation. MTT assays showed that some of these compounds had moderate to excellent cytotoxicity against the tested cancer cell lines and were more potent than 5-FU. Particularly, compound 5o represented excellent inhibitory effect toward EC-109 (IC50=0.3 μM), being about 33-fold more potent than 5-FU.

Microwave-assisted one-pot synthesis of steroid–quinoline hybrids and an evaluation of their antiproliferative activities on gynecological cancer cell lines

Steroidal and nonsteroidal ring-fused quinolines were efficiently synthesized under microwave conditions and their antiproliferative activities were investigated.

Efficient three-component one-pot synthesis of steroidal polysubstituted anilines

An efficient and practical base-promoted cascade reaction has been developed to access steroidal polysubstituted anilines from simple precursors. The protocol reported herein achieved the formation of a benzene ring as well as three continuous C-C bonds in a single operation. The reaction mechanism was proposed on the basis of the key intermediate obtained. Besides, this method could be potentially employed for the synthesis of biphenyl compounds. The adjacent amine and nitrile groups existed in the final products have the potential for late stage functionalization, which would provide efficient access to steroidal compound collections with structural diversity and complexity.

Efficient synthesis of novel antiproliferative steroidal spirooxindoles via the [3+2] cycloaddition reactions of azomethine ylides

A series of novel steroidal spirooxindoles 3a-h were synthesized from pregnenolone in a high regioselective manner using the 1,3-dipolar cycloaddition as the key step. This protocol resulted in the formation of two C-C bonds, one C-N bond and the creation of one pyrrolidine ring and three contiguous stereocenters in a single operation. Biological evaluation showed that these synthesized steroidal spirooxindoles exhibited moderate to good antiproliferative activity against the tested cell lines and some of them were more potent than 5-FU. Among them, compounds 3e and 3f displayed the best antiproliferative activity against MCF-7 cells with the IC50 values of 4.0 and 3.9μM, respectively. Flow cytometry analysis demonstrated that compound 3d caused the cellular apoptosis and cell cycle arrest at G2/M phase in a concentration-dependent manner. Docking results indicated that compound 3d fitted well into the MDM2 active site 1RV1 by interacting with Lys94 and Thr101 residues.

A Straightforward Approach toward Multifunctionalized Pyridazines via Imination/Electrocyclization

A facile synthesis of functionalized 3-carbamide pyridazines starting from readily available chlorovinyl aldehydes and oxamic acid thiohydrazides via cascade imination/electrocyclization is reported. In the presence of p-toluenesulfuric acid, various ketones have been efficiently incorporated into the pyridazine derivatives through a two-step sequence involving a Vilsmeier-Haack reaction and imination. The synthetic value of this method has been demonstrated by efficient synthesis of steroidal pyridazines.

Synthesis and in vitro antiproliferative evaluation of some B-norcholesteryl Benzimidazole and Benzothiazole derivatives

Taking orostanal (a compound from a Japanese marine sponge, Stelletta hiwasaensis) as a lead compound, some novel B-norcholesteryl benzimidazole and benzothiazole derivatives were synthesized. The antiproliferative activity of the compounds against human cervical carcinoma (HeLa), human lung carcinoma (A549), human liver carcinoma cells (HEPG2) and normal kidney epithelial cells (HEK293T) was assayed. The results revealed that the benzimidazole group was a better substituent than benzothiazole group for increasing the antiproliferative activity of compounds. 2-(3β′-Acetoxy-5β′-hydroxy-6′-B-norcholesteryl)benzimidazole (9b) with the structure of 6-benzimidazole displays the best antiproliferative activity to the cancer cells in all compounds, but is almost inactive to normal kidney epithelial cells (HEK293T). The assay of compound 9b to cancer cell apoptosis by flow cytometry showed that the compound was able to effectively induce cancer cell apoptosis. The research provided a theoretical reference for the exploration of new anti-cancer agents and may be useful for the design of novel chemotherapeutic drugs.

Synthesis, characterization and antitumor activities of some steroidal derivatives with side chain of 17-hydrazone aromatic heterocycle

Here a series of dehydroepiandrosterone-17-hydrazone and estrone-17-hydrazone derivatives possessing various aromatic heterocycle structures in 17-side chain of their steroidal nucleus were synthesized and their structures were evaluated. The antiproliferative activity of synthesized compounds against some cancer cells was investigated. The results have demonstrated that some dehydroepiandrosterone-17-hydrazone derivatives show distinct antiproliferative activity against some cancer cells through inducing cancer cell apoptosis, and compound 8 with a quinoline structure in 17-side chain displays excellent antiproliferative activity in vitro against SGC 7901 cancer cell (human gastric carcinoma) with an IC50 value of 1 μM. In addition, estrone-17-hydrazone derivatives having a key feature of indole group in the structure showed a special obvious cytotoxicity against HeLa cells, but almost inactive against other cells. The information obtained from the studies is valuable for the design of novel steroidal chemotherapeutic drugs.

Synthesis and characterization of steroidal heterocyclic compounds, DNA condensation and molecular docking studies and their in vitro anticancer and acetylcholinesterase inhibition activities

A facile and efficient approach for the synthesis of steroidal heterocyclic compounds (4–12) has been performed. Furthermore, these newly synthesized compounds were evaluated for their various biological activities.

Design, synthesis and biological evaluation of novel steroidal spiro-oxindoles as potent antiproliferative agents

Two series of novel steroidal spiro-pyrrolidinyl oxindoles 3a-t and 6a-c were designed and synthesized from dehydroepiandrosterone using the 1,3-dipolar cycloaddition as the key step and further evaluated for their antiproliferative activities for four human cancer cell lines (MGC-803, EC109, SMMC-7721 and MCF-7). This protocol achieved the formation of two CC bonds, one CN bond and the creation of one new five-membered pyrrolidine ring and three contiguous stereocenters in a single operation. Biological evaluation showed that these synthesized steroidal spiro-pyrrolidinyl oxindoles possessed moderate to good antiproliferative activities against the tested cell lines and some of them were more potent than 5-Fu. Particularly, compound 3g showed good antiproliferative activity against SMMC-7721 (IC50=0.71μM). Steroid dimer 6b showed improved antiproliferative activities against SMMC-7721 and MCF-7 with the IC50 values of 4.30 and 2.06μM, respectively. Flow cytometry analysis demonstrated that compound 3n caused the cellular early apoptosis and cell cycle arrest at G2/M phase in a concentration- and time-dependent manner. [Corrected]

Synthesis and biological evaluation of dehydroepiandrosterone-fused thiazole, imidazo[2,1-b]thiazole, pyridine steroidal analogues

A series of steroidal[17,16-d]thiazole, steroidal[1,2-b]pyridine and steroidal[17,16-d]thiazole[2,1-b]imidazo products were synthesized through a convenient and productive method. Anti-proliferation activity against EC109 (human esophageal carcinoma), EC9706 (human esophageal carcinoma) and MGC-803 (human gastric carcinoma) cell lines was examined in vitro. Among the screened compounds, several highly potential compounds were located.