An efficient one-pot synthesis generating 4-ene-3,6-dione functionalised steroids from steroidal 5-en-3beta-ols using a modified Jones oxidation methodology

Methyl Esters of 23,24-Dinor-5α-cholan-22-oic Acids as Brassinosteroid Analogues. Synthesis, Evaluation of Plant Growth Promoting Activity and Molecular Docking

Five new brassinosteroid analogues were synthetized from 3β-acetoxy-23,24-dinorchol-4-en-22-oic acid. All the obtained compound showed significant activity in the Rice Lamina Inclination Test. Interestingly the effects of the methyl ester of 3β-hydroxy-6-oxo-23,24-dinorcholan-22-oic acid (14) at concentrations of 1 x 10^-7 and 1 x 10^-6 M proved to be higher than those produced by brassinolide. In silico Molecular Docking and Induced fit docking (IFD) simulations for the compounds with the highest biological activity data were carried out to investigate the binding mode interactions into the brassinolide-binding groove which revealed that the compound 14 had high binding energy values and a good affinity.

Type 5 17-hydroxysteroid dehydrogenase/prostaglandin F synthase (AKR1C3) inhibition and potential anti-proliferative activity of cholest-4-ene-3,6-dione in MCF-7 breast cancer cells

Cholest-4-ene-3,6-dione (KS) is a cholesterol oxidation product which exhibits anti-proliferative activity. However, its precise mechanism of action remains unknown. In this study, the effects of KS on AKR1C3 inhibition and anti-proliferative activities were investigated in the hormone-dependent MCF-7 breast cancer cells. We identified that KS arrested the enzymatic conversion of estrone to 17-β estradiol, by inhibiting AKR1C3 in intact MCF-7 cells. The anti-proliferative effects of KS were evaluated by MTT assay, acridine orange and ethidium bromide dual staining, cell cycle analysis and Western blotting. KS arrested the cell cycle progression in the G1 phase with a concomitant increase of the Sub-G0 population to increase in concentration and time. It also enhanced the p53 and NFkB expression and induced caspase-12, 9 and 3 processing and down-regulated the Bcl-2 expression. Molecular docking studies performed to understand the inhibition mechanism of KS on AKR1C3 revealed that KS occupied the binding region of AKR1C3 with almost similar orientation as indomethacin (IM), thereby acting as an antagonistic agent for AKR1C3. Based on the results it is identified that KS induces inhibition of AKR1C3 and cell death in MCF-7 cells. These results indicate that KS can be used as a molecular scaffold for further development of novel small-molecules with better specificity towards AKR1C3.

Synthesis and Biological Activity of a Bis-steroid-Methanocyclobutanaphthalene- dione Derivative against Ischemia/Reperfusion Injury via Calcium Channel Activation

BACKGROUND

There is some experimental data on the effect exerted by some steroid derivatives against ischemia/reperfusion injury; however, the molecular mechanism is very confusing, perhaps this phenomenon could be due to the protocols used and/or differences in the chemical structure of each one of the steroid derivatives.

OBJECTIVES

The aim of this study was to synthesize a new bis-steroid-methanocyclobutanaphthalene- dione derivative using some tools chemical.

METHODOLOGY

The biological activity exerted by the bis-steroid-methanocyclobutanaphthalene- dione derivative against ischemia/reperfusion injury was evaluated in an isolated heart model using noradrenaline, milrinone, dobutamine, levosimendan, and Bay-K- 8644 as controls. In addition, other alternative experiments were carried out to evaluate the biological activity induced by the bis-steroid-methanocyclobuta-naphthalene-dione derivative against left ventricular pressure in the absence or presence of nifedipine.

RESULTS

The results showed that 1) the bis-steroid-methanocyclobuta-naphthalene-dione derivative significantly decreases the ischemia-reperfusion injury translated as a decrease in the the infarct area in a similar manner to levosimendan drug; 2) both bis-steroidmethanocyclobuta- naphthalene-dione and Bay-K-8644 increase the left ventricular pressure and 3) the biological activity exerted by bis-steroid-methanocyclobuta-naphthalenedione derivative against left ventricular pressure is inhibited by nifedipine.

CONCLUSION

In conclusion, the bis-steroid-methanocyclobuta-naphthalene-dione derivative decreases the area of infarction and increases left ventricle pressure via calcium channels activation; this phenomenon could constitute a new therapy for ischemia/reperfusion injury.

Anticancer activity of novel steroidal 6-substituted 4-en-3-one D-seco dinitriles

Steroidal 16,17-seco-16,17a-dinitriles possessing 4-ene-3,6-dione (3), 6-methylene-4-en-3-one (5), (6E)-hydroxyimino-4-en-3β-ol (9) or (6E)-hydroxyimino-4-en-3-one (10) moiety were synthesized starting from 3β-acetoxy-16,17-secoandrost-4-ene-16,17a-dinitrile (1). Antiproliferative activity of the newly synthesized compounds, as well as previously synthesized 3-oxo-16,17-secoandrosta-1,4-diene-16,17a-dinitrile (VII), was tested in vitro. Compound 9 displayed submicromolar antiproliferative activity against human cervical carcinoma (HeLa) cells (IC₅₀ 0.48 μM), and compounds 3 and 10 expressed strong inhibitory potential against HeLa cells (IC₅₀ 4.31 μM and 2.64 μM, respectively). Also, compound 10 was effective in inhibiting estrogen hormone-independent (MDA-MB-231) cells (IC₅₀ 2.78 μM). All tested compounds had no influence on the proliferation of healthy cells (MRC-5). Since MDA-MB-231 breast cancer cells and HeLa cervical cancer cells were most sensitive to treatment by 16,17-seco-16,17a-dinitriles, apoptosis induction after treatment by compounds 3, VII, 9 and 10 was studied in these cells, to reveal the mechanism underlying cell growth inhibition. All tested compounds significantly induced apoptosis in both treated cell lines, which was evident from results obtained by a double AO-EB staining test and quantified by counting cells with apoptotic morphology after staining with Giemsa dye. Among all tested substances, (6E)-hydroxyimino-4-en-3-one derivative 10 expressed the most proapoptotic activity.

Synthesis and biological evaluation of steroidal derivatives as selective inhibitors of AKR1B10

AKR1B10 is a member of human aldo-keto reductase superfamily, and a promising anti-cancer therapeutic target. In this paper, androst-5-ene-3β-ol, dehydroepiandrosterone, pregnenolone and cholesterol were used as reactants, sixteen products were obtained through Jones reaction and reduction reaction using NaBH4. Their inhibitory activities against AKR1B10 and AKR1B1 were measured. The most active compound (3a) has the IC50 of 0.50μM for AKR1B10, and the most AKR1B10 selective compound (2a) has the IC50 of 0.81μM with AKR1B1/AKR1B10 selectivity of 195. In addition, the binding modes of 2a and 3a in the active site of human AKR1B10 were identified by docking.

Recent advances in cholesterol chemistry

This review article presents advances in cholesterol chemistry since 2000. Various transformations (chemical, enzymatic, electrochemical, etc.) of cholesterol are presented. A special emphasis is given to cholesterol oxidation reactions, but also substitution of the 3β-hydroxyl group, addition to the C5-C6 double bond, C-H functionalization, and C-C bond forming reactions are discussed.

(Z)-3β-(2-Chloroanilino)-17(20)-pregnene

In the pregnene fragment of the title compound, C₂₇H₃₈ClN, the three six-membered rings exhibit chair conformations and the five-membered ring has a distorted envelope form with the fused C atom not bearing a methyl group as the flap atom. The amino group is involved in the formation of an intra­molecular N—H⋯Cl hydrogen bond. The crystal packing exhibits no short inter­molecular contacts.

Prevalent glucocorticoid and androgen activity in US water sources

Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

Diosgenone: a second P2(1) polymorph

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C₂₇H₄₀O₃] has been proposed as a new therapeutic alternative for the treatment of malaria. The first X-ray structure report for diosgenone was by Piro et al. [(2002). Z. Naturforsch. Teil C, 57, 947–950] in the space group P2₁ (Z′ = 2). We now report a new polymorph in the same space group, with two mol­ecules in the asymmetric unit. Both mol­ecules have similar conformations, characterized by a skewed envelope A ring, which contains the C=C bond conjugated with the ketone functionality at C3. The dimorphism results from a modification of the relative orientation of the mol­ecules in the asymmetric unit: two independent mol­ecules were arranged anti­parallel in the Piro report, while they are parallel in the present determination.

Triterpenes from Garcia parviflora. Cytotoxic evaluation of natural and semisynthetic friedelanes

Three new friedelane-type triterpenes, 1,2-dehydro-2,3-secofriedelan-3-oic acid (1), 1β-hydroxyfriedelin (2), and 3β-hydroxyfriedelan-23-oic acid (3), and the known compounds friedelin-3,4-lactone (4), acetyl aleuritolic acid (5), 4-hydroxy-5-propionyl-1,3-di-O-methylpyrogallol, elemicin, and (-)-syringaresinol were isolated from the leaves of Garcia parviflora. The structures of 1-3 were elucidated by spectroscopic methods, including 1D and 2D NMR, HREIMS, X-ray, and CD analysis. Some derivatives of 2 (6-14) were prepared via oxidation, reduction, and esterification. The natural triterpenes and the semisynthetic friedelane derivatives were tested for cytotoxic activity against human cancer cell lines U251, PC-3, K562, HCT-15, MCF-7, and SKLU-1. Compound 5 was cytotoxic against U251 cells.

Synthesis and antitumor activity of new D-seco and D-homo androstane derivatives

Starting from 3beta-hydroxy-17-oxo-16,17-secoandrost-5-ene-16-nitrile (1), the new 16,17-secoandrostane derivatives 4-9 were synthesized. On the other hand, 3beta-hydroxy-17-oxa-D-homoandrost-5-ene-16-one (10) yielded the new d-homo derivatives 12, 13 and 15. In vitro antiproliferative activity of selected compounds against three tumor cell lines (human breast adenocarcinoma ER+, MCF-7, human breast adenocarcinoma ER-, MDA-MB-231, prostate cancer AR-, PC-3, and normal fetal lung fibroblasts, MRC-5) was evaluated. Compounds 3 and 12 showed strong antiproliferative activity against PC-3 cells, the IC(50) values being 2 microM and 0.55 microM, respectively. Compounds 6 (10 microM) and 14 (9 microM) showed moderate activity against MDA-MB-231 cells. The synthesized compounds 1-3, 5-8, 10 and 12-15 were not toxic to normal fetal lung fibroblasts cells, MRC-5.

Allylic oxidations catalyzed by dirhodium caprolactamate via aqueous tert-butyl hydroperoxide: the role of the tert-butylperoxy radical

Dirhodium(II) caprolactamate exhibits optimal efficiency for the production of the tert-butylperoxy radical, which is a selective reagent for hydrogen atom abstraction. These oxidation reactions occur with aqueous tert-butyl hydroperoxide (TBHP) without rapid hydrolysis of the caprolactamate ligands on dirhodium. Allylic oxidations of enones yield the corresponding enedione in moderate to high yields, and applications include allylic oxidations of steroidal enones. Although methylene oxidation to a ketone is more effective, methyl oxidation to a carboxylic acid can also be achieved. The superior efficiency of dirhodium(II) caprolactamate as a catalyst for allylic oxidations by TBHP (mol % of catalyst, % conversion) is described in comparative studies with other metal catalysts that are also reported to be effective for allylic oxidations. That different catalysts produce essentially the same mixture of products with the same relative yields suggests that the catalyst is not involved in product-forming steps. Mechanistic implications arising from studies of allylic oxidation with enones provide new insights into factors that control product formation. A previously undisclosed disproportionation pathway, catalyzed by the tert-butoxy radical, of mixed peroxides for the formation of ketone products via allylic oxidation has been uncovered.

Jones oxidation and high performance liquid chromatographic analysis of cholesterol in biological samples

A simple pre-column derivatization procedure for HPLC analysis of cholesterol in biological samples was developed. Cholesterol was treated with chromic acid and sulfuric acid in acetone (the Jones oxidation) and cholest-4-en-3,6-dione was formed. The reaction was finished in 5 min at room temperature and the product showed a strong UV absorbance at 250 nm that enabled an HPLC detection limit of 0.2 pmol. With stigmasterol as an internal standard, the reaction was applied to the analysis of total and free cholesterol in serum and high-density lipoproteins and the analysis showed a within-run and total coefficient of variation of about 0.2% and 0.5%, respectively.