A Strain-Promoted Divergent Chemical Steroidation Unveils Potent Anti-Inflammatory Pseudo-Steroidal Glycosides.

The development of novel agents with immunoregulatory effects is a keen way to combat the growing threat of inflammatory storms to global health. To synthesize pseudo-steroidal glycosides tethered by ether bonds with promising immunomodulatory potential, we develop herein a highly effective deoxygenative functionalization of a novel steroidal donor (steroidation) facilitated by strain-release, leveraging cost-effective and readily available Sc(OTf)3 catalysis. This transformation produces a transient steroid-3-yl carbocation which readily reacts with O-, C-, N-, S-, and P-nucleophiles to generate structurally diverse steroid derivatives. DFT calculations were performed to shed light on the mechanistic details of the regioselectivity, underlying an acceptor-dependent steroidation mode. This approach can be readily extended to the etherification of sugar alcohols to enable the achievement of a diversity-oriented, pipeline-like synthesis of pseudo-steroidal glycosides in good to excellent yields with complete stereo- and regiospecific control for anti-inflammatory agent discovery. Immunological studies have demonstrated that a meticulously designed cholesteryl disaccharide can significantly suppress interleukin-6 secretion in macrophages, exhibiting up to 99% inhibition rates compared to the negative control. These findings affirm the potential of pseudo-steroidal glycosides as a prospective category of lead agents for the development of novel anti-inflammatory drugs.

From Marine Metabolites to the Drugs of the Future: Squalamine, Trodusquemine, Their Steroid and Triterpene Analogues.

This review comprehensively describes the recent advances in the synthesis and pharmacological evaluation of steroid polyamines squalamine, trodusquemine, ceragenins, claramine, and their diverse analogs and derivatives, with a special focus on their complete synthesis from cholic acids, as well as an antibacterial and antiviral, neuroprotective, antiangiogenic, antitumor, antiobesity and weight-loss activity, antiatherogenic, regenerative, and anxiolytic properties. Trodusquemine is the most-studied small-molecule allosteric PTP1B inhibitor. The discovery of squalamine as the first representative of a previously unknown class of natural antibiotics of animal origin stimulated extensive research of terpenoids (especially triterpenoids) comprising polyamine fragments. During the last decade, this new class of biologically active semisynthetic natural product derivatives demonstrated the possibility to form supramolecular networks, which opens up many possibilities for the use of such structures for drug delivery systems in serum or other body fluids.

Synthesis and biological evaluation of novel steroidal pyrazole amides as highly potent anticancer agents.

A series of thirty-six steroidal pyrazole amides, divided into two categories based on their main skeletons were designed and synthesized via a five-step synthetic route. The final product is obtained through Pinnick oxidation of pyrazole aldehydes to yield the corresponding acids, which then underwent amidation to afford the target products efficiently under mild reaction conditions. Structures of the desired compounds were confirmed by 1H NMR, 13C NMR, high resolution mass spectrometry; X-ray structural characterization of compound 16n was also obtained. The synthesized compounds were screened for their antiproliferative activity against four cancer cell lines (Pc-3 A549, Hela, HepG2) using the SRB method. Amides 10n, 16n, and 16p-16t exhibited moderate to high cytotoxic activities with IC50 values ranging from 2.05 to 8.73 µM. Of note, the hydrochloride derivative 16p displayed the highest activity towards PC-3 cells with IC50 values of 2.05 µM. Analysis of structure-activity relationships indicated that the presence of the diamine moiety and the aqueous solubility of the derivatives were vital factors for antiproliferative potency. Furthermore, molecule 16p induced PC-3 cells apoptosis and arrested cell cycle at G1 phase in a dose-dependent manner.

Design, synthesis, and antitumor activity evaluation of steroidal oximes.

Steroidal compounds were proven to be efficient drugs against several types of cancer. Oximes are also chemical structures frequently associated with anticancer activity. The main goal of this work was to combine the two referred structures by synthesizing steroidal oximes and evaluating them in several cancer cell lines. Compounds (17E)-5α-androst-3-en-17-one oxime (3,4 - OLOX), (17E)-3α,4α-epoxy-5α-androstan-17-one oxime (3,4 - EPOX), (17E)-androst-4-en-17-one oxime (4,5 - OLOX) and (17E)-4α,5α-epoxyandrostan-17-one oxime (4,5 - EPOX) were synthesized and their cytotoxicity evaluated in four human cancer cell lines, namely colorectal adenocarcinoma (WiDr), non-small cell lung cancer (H1299), prostate cancer (PC3) and hepatocellular carcinoma (HepG2). A human non-tumour cell line, CCD841 CoN (normal colon cell line) was also used. MTT assay, flow cytometry, fluorescence and hemocompatibility techniques were performed to further analyse the cytotoxicity of the compounds. 3,4 - OLOX was the most effective compound in decreasing tumour cell proliferation in all cell lines, especially in WiDr (IC50 = 9.1 µM) and PC3 (IC50 = 13.8 µM). 4,5 - OLOX also showed promising results in the same cell lines (IC50 = 16.1 µM in WiDr and IC50 = 14.5 µM in PC3). Further studies also revealed that 3,4 - OLOX and 4,5 - OLOX induced a decrease in cell viability accompanied by an increase in cell death, mainly by apoptosis/necroptosis for 3,4 - OLOX in both cell lines and for 4,5 - OLOX in WiDr cells, and by necrosis for 4,5 - OLOX in PC3 cells. These compounds might also exert their cytotoxicity by ROS production and are not toxic for non-tumour CCD841 CoN cells. Additionally, both compounds did not induce haemoglobin release, proving to be safe for intravenous administration. 3,4 - OLOX and 4,5 - OLOX might be the starting point for an optimization program towards the discover of new steroidal oximes for anticancer treatment.

Selenosteroids - promising hybrid compounds with pleiotropic biological activity: synthesis and biological aspects.

It is established that steroid based agents are an example of compounds obtained from natural patterns and are of great importance due to their application in the prevention and treatment of diseases. Selenosteroids are hybrids formed by attaching Se-moiety to a steroid molecule. In these types of hybrids, selenium can be present as selenide or as a part of selenosemicarbazones, isoselenocyanates, selenourea, etc. Attaching a Se-moiety to a biologically active steroid might enhance the biological properties of both fragments. Available literature indicates that these kinds of hybrids demonstrate significant anticancer activity, which renders them interesting in terms of medical use. In this review, we present various methods of synthesis and demonstrate that seleno-steroid compounds are promising molecules for further pharmaceutical application.

Highlights on Steroidal Arylidene Derivatives as a Source of Pharmacologically Active Compounds: A Review.

Steroids constitute a unique class of chemical compounds, playing an important role in physiopathological processes, and have high pharmacological interest. Additionally, steroids have been associated with a relatively low toxicity and high bioavailability. Nowadays, multiple steroidal derivatives are clinically available for the treatment of numerous diseases. Moreover, different structural modifications on their skeleton have been explored, aiming to develop compounds with new and improved pharmacological properties. Thus, steroidal arylidene derivatives emerged as a relevant example of these modifications. This family of compounds has been mainly described as 17ß-hydroxysteroid dehydrogenase type 1 and aromatase inhibitors, as well as neuroprotective and anticancer agents. Besides, due to their straightforward preparation and intrinsic chemical reactivity, steroidal arylidene derivatives are important synthetic intermediates for the preparation of other compounds, particularly bearing heterocyclic systems. In fact, starting from arylidenesteroids, it was possible to develop bioactive steroidal pyrazolines, pyrazoles, pyrimidines, pyridines, spiro-pyrrolidines, amongst others. Most of these products have also been studied as anti-inflammatory and anticancer agents, as well as 5α-reductase and aromatase inhibitors. This work aims to provide a comprehensive overview of steroidal arylidene derivatives described in the literature, highlighting their bioactivities and importance as synthetic intermediates for other pharmacologically active compounds.

Total Synthesis of Ritterazine B.

The first total synthesis of the cytotoxic alkaloid ritterazine B is reported. The synthesis features a unified approach to both steroid subunits, employing a titanium-mediated propargylation reaction to achieve divergence from a common precursor. Other key steps include gold-catalyzed cycloisomerizations that install both spiroketals and late stage C-H oxidation to incorporate the C7' alcohol.

Beyond Pseudo-natural Products: Sequential Ugi/Pictet-Spengler Reactions Leading to Steroidal Pyrazinoisoquinolines That Trigger Caspase-Independent Death in HepG2 Cells.

In this work, we describe how stereochemically complex polycyclic compounds can be generated by applying a synthetic sequence comprising an intramolecular Ugi reaction followed by a Pictet-Spengler cyclization on steroid-derived scaffolds. The resulting compounds, which combine a fragment derived from a natural product and a scaffold not found in nature. are both structurally distinct and globally similar to natural products at the same time, and interrogate an alternative region of the chemical space. One of the new compounds showed significant antiproliferative activity on HepG2 cells through a caspase-independent cell-death mechanism, an appealing feature when new antitumor compounds are searched.

Combined experimental and quantum mechanical elucidation of the synthetically accessible stereoisomers of Hydroxyestradienone (HED), the starting material for vilaprisan synthesis.

Selective progesterone receptor modulators are promising therapeutic options for the treatment of uterine fibroids. Vilaprisan, a new chemical entity that was discovered at Bayer is currently in clinical development. In this study we provide a combined experimental and quantum chemical approach providing the data that allowed to present hydroxyestradienone as an acceptable starting material for drug substance synthesis. Hydroxyestradienone has four stereogenic centers leading to 8 diastereomers and 16 enantiomers of which only six diastereomers were synthetically accessible but two not. A computational multistep protocol resulting in density functional P2PLYP-D3(BJ)/dev2-TZVPP Gibbs free energies and SMD solvation free energies led to a clear separation between the existing and the synthetically not accessible enantiomers, whereas multiple geometry-based and cheminformatic descriptors were not able to explain experimental findings.

Synthesis of 17ß-hydroxysteroid dehydrogenase type 10 steroidal inhibitors: Selectivity, metabolic stability and enhanced potency.

17beta-Hydroxysteroid dehydrogenase type 10 (17ß-HSD10) is the only mitochondrial member of 17ß-HSD family. This enzyme can oxidize estradiol (E2) into estrone (E1), thus reducing concentration of this neuroprotective steroid. Since 17ß-HSD10 possesses properties that suggest a possible role in Alzheimer's disease, its inhibition appears to be a therapeutic strategy. After we identified the androsterone (ADT) derivative 1 as a first steroidal inhibitor of 17ß-HSD10, new analogs were synthesized to increase the metabolic stability, to improve the selectivity of inhibition over 17ß-HSD3 and to optimize the inhibitory potency. From six D-ring derivatives of 1 (17-CO), two compounds (17ß-H/17α-OH and 17ß-OH/17α-CCH) were more metabolically stable and did not inhibit the 17ß-HSD3. Moreover, solid phase synthesis was used to extend the molecular diversity on the 3ß-piperazinylmethyl group of the steroid base core. Eight over 120 new derivatives were more potent inhibitors than 1 for the transformation of E2 to E1, with the 4-(4-trifluoromethyl-3-methoxybenzyl)piperazin-1-ylmethyl-ADT (D-3,7) being 16 times more potent (IC50 = 0.14 µM). Finally, D-ring modification of D-3,7 provided 17ß-OH/17α-CCH derivative 25 and 17ß-H/17α-OH derivative 26, which were more potent inhibitor than 1 (1.8 and 2.4 times, respectively).

Synthesis and anticancer potential of novel 5,6-oxygenated and/or halogenated steroidal d-homo lactones.

A series of 5,6-modified steroidal d-homo lactones, comprising of halogenated and/or oxygenated derivatives, was synthesized and evaluated for potential anticancer properties. Preparation of many of these compounds involved investigating alternative synthetic pathways. In silico ADME testing was performed for both novel and some previously synthesized compounds. Calculated physicochemical properties were in accordance with the Lipinski, Veber, Egan, Ghose and Muegge criteria, suggesting the potential of these molecules as orally active agents. Cytotoxicity of the synthesized steroid derivatives was tested on six tumor and one normal human cell line. None of the investigated derivatives was toxic to non-cancerous MRC-5 control cells. Most of the compounds showed significant cytotoxicity against the treated cancer cell lines. Most notably, the 3ß,5α,6ß-trihydroxy derivative exhibited strong cytotoxicity against multiple cell lines (MCF-7, MDA-MB-231 and HT-29), with the highest effect observed for lung adenocarcinoma (A549) cells, for which this steroid was more cytotoxic than all of the three commercial chemotherapeutic agents used as reference compounds. Molecular docking suggests the 3ß,5α,6ß-trihydroxy derivative could bind the EGFR tyrosine kinase domain with high affinity, providing a potential mechanism for its cytotoxicity via inhibition of EGFR signaling. The most active compounds were further studied for their potential to induce apoptosis by the double-staining fluorescence method; where the 5α,6ß-dibromide, 5α,6ß-dichloride and 3ß,5α,6ß-triol induced apoptotic changes in all three treated cell lines: MDA-MB-231, HT-29 and A549. To predict interactions with nuclear steroidal receptors, affinity for the ligand binding domains of ERα, ERß and AR was measured using a yeast-based fluorescence assay. The 5ß,6ß-epoxide, dibromide and 5α-hydroxy-3,6-dioxo derivatives showed affinity for ERα, while the 5α-fluoro-6ß-hydroxy and 3ß-acetoxy-5α,6ß-dihydroxy derivatives were identified as ERß ligands. None of the tested compounds showed affinity for AR. Structure-activity relationships of selected compounds were also examined.

Novel d-Annulated Pentacyclic Steroids: Regioselective Synthesis and Biological Evaluation in Breast Cancer Cells.

The acid-catalyzed cyclization of benzylidenes based on 16-dehydropregnenolone acetate (16-DPA) was studied. It was found that these compounds readily undergo regioselective interrupted Nazarov cyclization with trapping chloride ion and an efficient method of the synthesis of d-annulated pentacyclic steroids based on this reaction was proposed. The structures of the synthesized pentacyclic steroids were determined by NMR and X-ray diffraction. It was found that the reaction affords a single diastereomer, but the latter can crystallize as two conformers depending on the structure. Antiproliferative activity of synthesized compounds was evaluated against two breast cancer cell lines: MCF-7 and MDA-MB-231. All tested compounds showed relatively high antiproliferative activity. The synthetic potential of the protocol developed was illustrated by the gram-scale experiment.

Antitumor and hepatoprotective activity of natural and synthetic neo steroids.

In this review, steroids with a tertiary butyl group, which are usually called neo steroids, are a small group of natural lipids isolated from higher plants, fungi, marine sponges, and yeast. In addition, steroids with a tertiary butyl group have been synthesized in some laboratories in Canada, USA, Europe, and Japan and their biological activity was studied. Some natural neo steroids demonstrate antitumor or hepatoprotective activities. In addition, synthetic neo steroids exhibit anticancer and neuroprotective properties. However, to confirm the above data, both practical and clinical experimental studies are necessary. Nevertheless, the results may be useful for pharmacologists, chemists, biochemists, and the pharmaceutical industry.

Fe(iii)-Catalyzed synthesis of steroidal imidazoheterocycles as potent antiproliferative agents.

An efficient and practical method has been developed for the synthesis of steroidal imidazoheterocycles via cost-effective and environmentally benign FeCl3-catalyzed oxidative amination. A library of steroidal imidazo[1,2-a]pyridines was directly synthesized from readily available 2-aminopyridines and steroidal ketones in aerobic conditions. The synthesized compounds were screened for activity on human microsomal cytochrome P450s CYP7, CYP17 and CYP21. Antiproliferative activity of two lead compounds 3ia and 3la was additionally evaluated against the human MCF-7 (breast cancer), SKOV3 (ovarian cancer), and 22Rv1 (prostate cancer) cell lines. Steroidal imidazo[1,2-a]pyridine 3la which is a substrate molecule for CYP17A1 with IC50 = 1.7 µM (MCF-7), 3.0 (SKOV3), and 6.0 µM (22Rv1) has proved to be more active than reference drug cisplatin.

New CDK8 inhibitors as potential anti-leukemic agents - Design, synthesis and biological evaluation.

Cyclin-dependent kinase 8 (CDK8) plays a vital role in regulating cell transcription either through its association with the mediator complex or by the phosphorylation of transcription factors. CDK8-mediated activation of oncogenes has proved to be important in a variety of cancer types including hematological malignancies. We have designed and synthesized a series of new synthetic steroids. The compounds were evaluated as CDK8 inhibitors in vitro. The three most potent compounds exhibit Kd-values towards CDK8 in the low nanomolar range (3.5-18 nM). Furthermore, the compounds displayed selectivity for CDK8 in a panel of 465 different kinases. The cell studies indicated a selectivity to kill AML-cancer cell lines compared to normal cell lines.

Design, Synthesis, and Biological Evaluation of Two Series of Novel A-Ring Fused Steroidal Pyrazines as Potential Anticancer Agents.

BACKGROUND: Increasingly, different heterocyclic systems have been introduced into the steroid nucleus to significantly enhance the antitumor activities of steroid molecules. However, in this study, few literature precedents describing the pyrazine heterocyclic-condensed modification to an A-ring of steroid monomers were found, although the pyrazine group is thought to be essential for the potent anticancer activity of clinically relevant drugs and natural steroid dimers. METHODS AND RESULTS: Two series of novel A-ring fused steroidal pyrazines were designed and efficiently synthesized from commercially available progesterone via key α-ketoenol intermediates. Through a cell counting kit-8 cytotoxic assay of 36 derivatives for three tumor cells, 14 compounds displayed significant antiproliferative activity compared to 5-fluorouracil, especially for human prostatic tumor cells (PC-3) in vitro. Further mechanistic studies indicated that the most active compound, 12n (IC50, 0.93 µM; SI, 28.71), could induce the cell apoptosis of PC-3 cells in a dose-dependent manner and cause cell cycle arrest in the G2/M phase. The molecular docking study suggested that compound 12n fitted the active sites of cytochrome P450 17A1 (6CIZ) well. CONCLUSIONS: 12n might serve as a promising lead compound for the development of novel anticancer drugs. This facile ring-closing strategy may provide a novel and promising avenue for the cycloaddition reaction of the steroidal skeleton through α-ketoenol intermediates.

Biological activity and apoptotic signaling pathway of C11-functionalized cephalostatin 1 analogues.

Cephalostatin 1, a potent anti-cancer agent, is a natural bis-steroidal alkaloid that causes cell death in the subnanomolar to picomolar ranges via an atypical apoptosis pathway. Although cephalostatin 1 is a highly effective anticancer drug, its availability limits its utilization. We previously reported the synthesis of two 12'α-hydroxy derivatives of cephalostatin 1 that induce cell death by activating the ER stress apoptosis signaling pathway. For the current work, we synthesized six C11-functionalized cephalostatin 1 analogues (CAs) to evaluate their biological activity. For the cytotoxic compounds, the induced apoptotic pathway was investigated. The C11-functionalized cephalostatin 1 analogues 5 and 6 (CA5 and CA6) were found to exhibit cytotoxic activity against K-562 leukemia cells, MCF-7 breast cancer cells and DU-145 prostate cancer cells, while the remaining four analogues did not show anti-tumor activities against any of the cell lines. Our results indicated that CA5 and CA6 induced cell death via the atypical ER-dependent apoptosis pathway; they increased the expression of Smac/DIABLO, an inhibitor of inhibitors of apoptosis (IAPs), which in turn facilitated the activation of different caspases including the ER-caspase 4 without cytochrome c release from mitochondria. CA5 and CA6 are promising anticancer agents due to their low GI50, the remarkable apoptosis pathway they induce which can overcome chemoresistance, and their very low toxicity to normal cells making them cephalostatin 1 utilizable alternatives.

Design, synthesis and biological evaluation of novel 5α, 8α-endoperoxide steroidal derivatives with hybrid side chain as anticancer agents.

A series of novel 5α, 8α-endoperoxide steroidal hybrid derivatives containing isatin or indole substituents on the C-17 side chain were synthesized and characterized. The preliminary anti-proliferative activity of the compounds against HepG2, MCF-7, HT-29 and HeLa cell lines were investigated. Compounds 7g and 7l displayed significant anti-proliferative activity in vitro against HepG2 and Hela cells, with IC50 values lower than 8 µM. Furthermore, the biological functions of 7g were examined by flow cytometry and colony analysis. The results showed that 7g could induce HepG2 cell apoptosis, inhibited cell cycle progression, and colony growth. The studies indicated that structural modification at C-17 position could be a promising launch point for design steroidal anticancer agents.

Synthesis of novel hybrid hetero-steroids: Molecular docking study augmented anti-proliferative properties against cancerous cells.

Hetero-steroids, hybrid anticancer agents, have received much interest in view of their numerous and promising biological activities. In this study, a novel class of hetero-steroids were synthesized, analytical and spectral data proved the validity of the novel synthesized steroid derivatives. The cytotoxicity of the synthesized compounds 2, 5, 6, 7, 10, 11, 12, 14, 15, 17 were evaluated using human hepatocellular carcinoma cell lines (HepG2 and Huh-7) and non-small cell lung cancer (A549) cell lines. The synthesized compounds reported a remarkable gradual decrease in the cell viability of the three tested cancer cell lines. It was observed that compounds 2 and 12 had the lowest IC50s and the highest cytotoxic effects against all tested cell lines. As attempt to explain the cytotoxic activity achieved by the tested compounds in the in vitro study, molecular simulation was done to reveal the activity of the tested compounds against four different proteins (CDK2, CYP19, JAK2, and BCL2) which are highly implicated in cancer regulation and progression. We found that compound 2, and 12 were the best docked compounds against all tested receptors, which was indicated by lowest binding energy compared to reference ligand. Interestingly enough, our molecular study was in agreement with the cytotoxic activity. As future prospective, we are recommending further study on compounds 2, and 12 against the four different proteins to prove their mode of action.

Role of human 3α-hydroxysteroid dehydrogenase isoforms (AKR1C1-AKR1C3) in the extrahepatic metabolism of the steroidal aromatase inactivator Formestane.

The clinical use of the steroidal aromatase inhibitor Formestane (4-hydroxandrostenedione, 4-OHA) in the treatment of advanced ER+ breast cancer has been discontinued, and therefore, interest in this remarkable drug has vanished. As a C-19 sterol, 4-OHA can undergo extensive intracellular metabolism depending on the expression of specific enzymes in the corresponding cells. We used the metabolites 4ß-hydroxyandrosterone, 4ß-hydroxyepiandrosterone and its 17ß-reduced derivative as standards for the proof of catalytic activity present in the cell culture medium and expressed by the isolated enzymes. All of the aldo-keto reductases AKR1C1, AKR1C2, AKR1C3 and AKR1C4 catalysed the reduction of the 3-keto-group and the Δ4,5 double bond of 4-OHA at the same time. Molecular docking experiments using microscale thermophoresis and the examination of the kinetic behaviour of the isolated enzymes with the substrate 4-OHA proved that AKR1C3 had the highest affinity for the substrate, whereas AKR1C1 was the most efficient enzyme. Both enzymes (AKR1C1and AKR1C3) are highly expressed in adipose tissue and lungs, exhibiting 3ß-HSD activity. The possibility that 4-OHA generates biologically active derivatives such as the androgen 4-hydroxytestosterone or some 17ß-hydroxy derivatives of the 5α-reduced metabolites may reawaken interest in Formestane, provided that a suitable method of administration can be developed, avoiding oral or intramuscular depot-injection administration.