Synthesis and estrogen activity screening of some new D-secoestrone derivatives

Secosteroid thiosemicarbazides and secosteroid-1,2,4-triazoles as antiproliferative agents targeting breast cancer cells: Synthesis and biological evaluation

A convenient and selective approach to 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-arylcarbothioamido]hydrazides and hybrid molecules containing secosteroid and 1,2,4-triazole fragments was disclosed and these novel types of secosteroids were screened for cytotoxicity against hormone-dependent human breast cancer cell line MCF-7. Most of secosteroid-1,2,4-triazole hybrids showed significant cytotoxic effect comparable or superior to that of the reference drug cisplatin. Hit secosteroid-1,2,4-triazole hybrids 4b and 4h were characterized by high cytotoxicity and good selectivity towards MCF-7 breast cancer cells. PARP cleavage (marker of apoptosis) and ERα and cyclin D1 downregulation were discovered in MCF-7 cells treated with lead secosteroid-1,2,4-triazole hybrid 4b. The synthesized secosteroids may be considered as new promising anticancer agents.

Secosteroid-quinoline hybrids as new anticancer agents

An elegant approach to unknown secosteroid-quinoline hybrids is disclosed. A series of 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(iso)quinolylmethylene]hydrazides was prepared and these novel type of secosteroids was screened for antiproliferative activity against estrogen-responsive human breast cancer cell line MCF-7. Most of the synthesized compounds showed a cytotoxic effect superior to that of reference drug cisplatin; the lead compound exhibits the highest activity with the IC₅₀ value of about 0.8 μM and is 7 times more active than cisplatin. A high selectivity index was observed for the hit 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-quinolylmethylene]hydrazides 2a and 2c. Compounds 2a and 2c evaluated in luciferase reporter assays exhibited high antiestrogenic potency which was superior to that of tamoxifen. These hit compounds were characterized by high activity against MCF-7 cells that retained towards multidrug-resistant NCI/ADR-RES cells.

Secosteroidal hydrazides: Promising scaffolds for anti-breast cancer agents

A convenient and selective approach to 13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazides and their N'-(het)arylmethylene derivatives was disclosed and these novel types of secosteroids were screened for cytotoxicity against hormone-dependent human breast cancer cell line MCF-7. A number of 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(het)arylmethylene]hydrazides show significant cytotoxic effect comparable or superior to that for reference drug cisplatin. Compound 3l exhibits the highest activity with the IC₅₀ value of about 2 μM and is 2.8 times more active than cisplatin. Hit 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(het)arylmethylene]hydrazides 3d, 3l and 3q are characterized by high cytotoxicity and good selectivity towards MCF-7 breast cancer cells. The synthesized secosteroids may be considered as new promising antitumor agents.

Identification of d-seco modified steroid derivatives with affinity for estrogen receptor α and β isoforms using a non-transcriptional fluorescent cell assay in yeast

Synthesis and biological evaluation of steroidal derivatives with anticancer properties is an active area of drug discovery. Here we measured the relative affinities of d-seco modified steroidal derivatives for estrogen receptor α, estrogen receptor β or androgen receptor ligand binding domains using an optimized non-transcriptional fluorescent cell assay in yeast. Ligand binding domains of steroid receptors were expressed in-frame with yellow fluorescent protein in the yeast Saccharomyces cerevisiae. Addition of known steroid ligands to yeast expressing the appropriate cognate receptor results in increased fluorescence intensity, enabling estimation of receptor binding affinities in a dose-response and time-dependent manner. Relative binding affinities of d-seco modified steroidal derivatives 1-4 were then evaluated using this yeast system by live cell fluorimetry and fluorescence microscopy, coupled with in vitro cytotoxicity and in silico molecular docking studies. d-Seco estratriene derivative 2displayed strong affinity for both estrogen receptor α and β ligand binding domains and negligible affinity for the androgen receptor ligand binding domain. Compound 2 also showed moderate cytotoxicity against estrogen receptor positive MCF-7 breast adenocarcinoma cells. In addition to identification of new ligands for steroid receptors, this assay could also be used to filter out compounds with potential for off-target interactions with steroid receptors during the early stages of compound screening.

Mechanism of antiproliferative action of a new d-secoestrone-triazole derivative in cervical cancer cells and its effect on cancer cell motility

Cervical cancer is the fourth most frequently diagnosed tumor and the fourth leading cause of cancer death in females worldwide. Cervical cancer is predominantly related with human papilloma virus (HPV) infection, with the most oncogenic types being HPV-18 and -16. Our previous studies demonstrated that some d-secoestrone derivatives exert pronounced antiproliferative activity. The aim of the current investigation was to characterize the mechanism of action of d-secoestrone-triazole (D-SET) on three cervical cancer cell lines with different pathological backgrounds. The growth-inhibitory effects of D-SET were determined by a standard MTT assay. We have found that D-SET exerts a pronounced growth-inhibitory effect on HPV 18-positive HeLa and HPV-negative C-33 A cells, but it has no substantial inhibitory activity on HPV 16-positive SiHa or on intact fibroblast MRC-5 cell lines. After 24h incubation, cells showed the morphological and biochemical signs of apoptosis determined by fluorescent double staining, flow cytometry and caspase-3 activity assay. Besides the elevation of the ratio of cells in the subG1 phase, flow cytometric analysis revealed a cell cycle arrest at G2/M in both HeLa and C-33 A cell lines. To distinguish the G2/M cell population immunocytochemical flow cytometric analysis was performed on HeLa cells. The results show that D-SET significantly increases the ratio of phosphorylated histone H3, indicating cell accumulation in the M phase. Additionally, D-SET significantly increased the maximum rate of microtube formation measured by an in vitro tubulin polymerization assay. Besides its direct antiproliferative activity, the antimigratory property of D-SET has been investigated. Our results demonstrate that D-SET significantly inhibits the migration and invasion of HeLa cells after 24h incubation. These results suggests that D-SET is a potent antiproliferative agent against HPV 16+ and HPV-negative cervical cancer cell lines, with an efficacious motility-inhibiting activity against HPV 16+ cells. Accordingly D-SET can be regarded as a potential drug candidate with a promising new mechanism of action among the antiproliferative steroids, potentially allowing for the design of novel anticancer agents.

Syntheses and antiproliferative effects of D-homo- and D-secoestrones

Substituted and/or heterocyclic d-homoestrone derivatives were synthetized via the intramolecular cyclization of a δ-alkenyl-d-secoaldehyde, -d-secoalcohol or -d-secocarboxylic acid of estrone 3-benzyl ether. The d-secoalcohol was modified at three sites in the molecule. The in vitro antiproliferative activities of the new d-homo- and d-secoestrone derivatives were determined on HeLa, MCF-7, A431 and A2780 cells through use of MTT assay. d-Homoalcohols 3 and 5 displayed cell line-selective cytostatic effects against ovarian and cervical cell lines, respectively. Two d-secoestrones (6 and 12c) proved to be effective, with IC50 values comparable with those of the reference agent cisplatin. A selected compound (6) was tested by tubulin polymerization assay and its cancer specificity was additionally determined by using noncancerous human fibroblast cells.

Synthesis, crystal structure and antiaromatase activity of 17-halo-16,17-seco-5-androstene derivatives

Starting from 3?-acetoxy-15-cyano-17-oxo-16,17-seco-5-androstene (2) and 3?-acetoxy- 15-cyano-17-hydroxy-17-methyl-16,17-seco-5-androstene (11), new 17-halo-derivatives (5?10 and 13) were obtained. The fluoro derivative 5 was obtained from 17-tosylate 4 in reaction with tetrabutylammonium fluoride. The structure of the 17-iodo-devitive 10 was unambiguously proved by the appropriate X-ray structural analysis. Compounds5?10, as well as 12 and 13 were tested for possible anti-aromatase activity, whereby only compound 9 with bromine as the C-17 substituent, induced 19.4 % inhibition of aromatase activity compared to the control.

Retention behaviour of some estradiol derivatives on alumina in normal phase chromatrography

The retention constants of variously substituted estradiol derivatives were measured as a function of the composition of various binary mobile phases in order to study the relationship between chemical structure and retention behavior in TLC on alumina. The slopes and intercepts of the linear relationships between the retention constant RM and the logarithm of the volume fraction of the polar mobile phase component were calculated and are discussed in relation to the characteristics of the solute and mobile phase. The RF values and relative retention ?RM of the compounds depend largely on the retention behavior of their substituents. The results obtained in this investigation are compared with the results of the same derivatives obtained in previous investigations on silica gel.

Synthesis of 3-benzyloxyl-17-maleyloxy-16, 17-secoestra- 1, 3, 5 (10)-triene-16-nitrile - Sinteza 3-benziloksi-17-maleiloksi- 16, 17-sekoestra-1, 3, 5 (10)-trien-16-nitrila

Under the conditions of Beckmann fragmentation reaction 3-benzyloxy-17(-hydroxyestra-1, 3, 5, (10)-triene-16-one oxime (2) gave the D-seco derivative 3. Sodium borohydride reduction of this compound afforded 3-benzyloxy-17-hydroxy-16, 17-secoestra-1, 3, 5 (10)-triene-16-nitrile (4). The esterification of seco-cyanoalcohol 4 was achieved by action of maleic acid anhydride in dry pyridine, yielding 3-benzyloxy-17-maleyloxy-16 17-secoestra-1, 3, 5 (10)-triene-16-nitrile (5).

Synthesis and Biological Activity of New 16,17-Secoestrone Derivatives

Starting from estrone 3-benzyloxy-17β-hydroxyestra-1,3,5(10)-trien-16-one oxime (3b) was synthesized, which underwent Beckmann fragmentation giving the 3-benzyloxy-17-oxo- 16,17-secoestra-1,3,5(10)-triene-16-nitrile (4b). Sodium borohydride reduction of this compound afforded 3-benzyloxy-17-hydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile (5b). The deprotection of the 3-hydroxy group was achieved by action of hydrogen upon derivatives4band5bin presence of Pd/C as a catalyst, yielding 3-hydroxy-17-oxo-16,17-secoestra- 1,3,5(10)-triene-16-nitrile (4a) and 3,17-dihydroxy-16,17-secoestra-1,3,5(10)-triene-16-nitrile (5a). In biological tests on experimental animals, compounds4a,4b,5aand5bshowed virtually a complete loss of estrogenic activity, whereas compounds4a,5aand5bexhibited moderate antiestrogenic effect.