Selective Anticancer Activity of Hydroxyapatite/Chitosan-poly(d,l)-lactide-co-glycolide Particles Loaded with an Androstane-Based Cancer Inhibitor

In an earlier study we demonstrated that hydroxyapatite nanoparticles coated with chitosan-poly(d,l)-lactide-co-glycolide (HAp/Ch-PLGA) target lungs following their intravenous injection into mice. In this study we utilize an emulsification process and freeze drying to load the composite HAp/Ch-PLGA particles with 17β-hydroxy-17α-picolyl-androst-5-en-3β-yl-acetate (A), a chemotherapeutic derivative of androstane and a novel compound with a selective anticancer activity against lung cancer cells. 1H NMR and 13C NMR techniques confirmed the intact structure of the derivative A following its entrapment within HAp/Ch-PLGA particles. The thermogravimetric and differential thermal analyses coupled with mass spectrometry were used to assess the thermal degradation products and properties of A-loaded HAp/Ch-PLGA. The loading efficiency, as indicated by the comparison of enthalpies of phase transitions in pure A and A-loaded HAp/Ch-PLGA, equaled 7.47 wt.%. The release of A from HAp/Ch-PLGA was sustained, neither exhibiting a burst release nor plateauing after three weeks. Atomic force microscopy and particle size distribution analyses were used to confirm that the particles were spherical with a uniform size distribution of d50 = 168 nm. In vitro cytotoxicity testing of A-loaded HAp/Ch-PLGA using MTT and trypan blue dye exclusion assays demonstrated that the particles were cytotoxic to the A549 human lung carcinoma cell line (46 ± 2%), while simultaneously preserving high viability (83 ± 3%) of regular MRC5 human lung fibroblasts and causing no harm to primary mouse lung fibroblasts. In conclusion, composite A-loaded HAp/Ch-PLGA particles could be seen as promising drug delivery platforms for selective cancer therapies, targeting malignant cells for destruction, while having a significantly lesser cytotoxic effect on the healthy cells

Synthesis and antiproliferative activity of some A- and B modified D-homo lactone androstane derivatives

An efficient synthesis of several A- and B-modified D-homo lactone androstane derivatives from 3β-hydroxy-17-oxa-D-homoandrost-5-en-16-one (1) is reported. 17-Oxa-Dhomoandrost- 4-ene-3,16-dione (2), obtained by the Oppenauer oxidation of compound 1, was converted via the unstable intermediate 3,16-dioxo-4,17-dioxa-D-homoandrostane- 5α-carboxaldehyde (3) to 17-oxa-D-homo-3,5-seco-4-norandrostan-5-one-3-carboxylic acid (4), which was also obtained directly from compound 2. Compound 1 was acetylated to give 17-oxa-D-homoandrost-5-en-16-on-3β-yl acetate (5) which was then oxidized with chromium(VI)-oxide in 50% acetic acid or with meta-chlorperbenzoic acid and chromium(VI)-oxide to yield compounds 6-8 and 5α-hydroxy-17-oxa-D-homoandrostane- 6,16-dion-3β-yl acetate (9), respectively. The oximination of compound 9 gave a mixture of 6(E)-hydroximino-5α-hydroxy-17-oxa-D-homoandrostan-16-on-3β-yl acetate (10) and 6(Z)-hydroximino-5α-hydroxy-17-oxa-D-homoandrostan-16-on-3β-yl acetate (11), the hydrolysis of which gave 6(E)-hydroximino-3β,5α-dihydroxy-17-oxa-D-homoandrostan- 16-one (12) and 6(Z)-hydroximino-3β,5α-dihydroxy-17-oxa-D-homoandrostan-16-one (13). 6-Nitrile-17-oxa-5,6-seco-D-homoandrostane-5,16-dion-3β-yl acetate (14) was obtained under the Beckmann fragmentation of compounds 10 and 11. Only pure and stable compounds (1, 2, 4, 5, 9 and 14) were tested in vitro on six malignant cell lines (MCF-7, MDA-MB-231, PC-3, HeLa, HT-29, K562) and one non-tumor MRC-5 cell line. Significant antiproliferative activity against MDA-MB-231 cells showed compounds 1, 5 and 9, while compound 2 exhibited a strong antiproliferative activity. Only compound 14 showed weak antiproliferative activity against MCF-7 cells. All tested compounds were not toxic on MRC-5 cells, whereas Doxorubicin was highly toxic on these cells. [Projekat Ministarstva nauke Republike Srbije, br. 172021

Synthesis of some D-homo-D-aza estratriene derivatives

In this paper two synthetic routes for obtaining D-homo-D-aza estratriene derivatives were described. Namely, starting from 3-methoxyestra-1,3,5(10)-trien-16-oximino-17-one (1) 3-methoxy-17-aza-D-homoestra-1,3,5(10)-triene (5) was synthesized in two step. Another D-aza derivative was synthesize, starting from 3-methoxy-17-oxo-16,17-secoestra-1,3,5(10)-trien-16-nitrile (6). For that purpose, the seco-cyanoaldehyde was converted into its 17-ethylenacetal 7 followed by subsequent reduction of the nitrile function with sodium borohydride in the presence of cobalt chloride hexahydrate. Finally, under acidic conditions the obtained 16-amino-17-ethylenacetal 8 was transformed into 3-metoxy-17-aza-D-homoestra-1,3,5(10),17(17a)-tetraene (9)

SCIENTIFIC WORK SYNTHESIS OF SOME 16,17-SECO- ANDROST-5-ENE DERIVATIVES

16,17-secoandrost-5-ene-16-nitrile (4) was synthesized by a three-stage procedure. First, the formyl group of compound 1 was reduced, to yield the alcohol 2. Compound 2 was further transformed to the mesyloxy derivative 3, whose reduction with NaBH 3CN gave compound 4. Apart from compound 4 as the main reaction product, two additional products were obtained, for which the GC/MS analysis suggested that they are Δ 8(14) and Δ 14 derivatives of compound 4. Compound 4 was transformed into 3β-hydroxy-16,17-secoandrost-5-ene-16-nitrile (7), the Oppenauer oxidation of which afforded 3-oxo-16,17-secoandrost-4-ene-16-nitrile (8). UDC 547.92.057:615.2 DOI: 10.2298/HEMIND100212009G There are various ways of reducing the C=O group of aldehydes and ketones to a CH2 [1]. The two oldest methods are the Wolff–Kishner reduction and the Clemensen reduction. In the Wolff–Kishner reduction, the aldehyde or ketone is heated with hydrazine hydrate an

SYNTHESIS AND CYTOTOXIC ACTIVITY OF A SERIES OF BILE ACID DERIVATIVES

The new conjugates of selected bile acids (hyocholic (2), deoxycholic (3), hyodeoxycholic (4) and 12-ketocholic (5) acids) with ethyl 11-aminoundecanoate 7, 8, 11, and 13 were synthesized. The conjugation reaction was carried out in ethyl acetate in the presence of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) and triethylamine. Under the same experimental conditions, the conjugation reaction involving ethyl 6-aminohexanoate resulted in formation of a conjugate 9 only in the case of deoxycholic acid (3) in addition to the unexpected ethyl ester 10. In the case of the other bile acids (cholic (1), hyodeoxycholic (4) and 12-ketocholic (5) acids) only an unexpected ester formation took place giving esters 6, 12, and 14. Cytotoxic activity against four tumor cell lines (human breast adenocarcinoma ER-, MDA-MB-231; breast adenocarcinoma ER+, MCF-7; cervix epiteloid carcinoma, HeLa S-3; and prostate cancer, PC-3) was evaluated. Conjugate 8 showed strong activity against HeLa S-3 and conjugate 11 for PC-3. Ethyl ester of 12-ketocholic acid 14 showed very strong antiproliferative activity against MCF-7 and HeLa S-3. Studies of bile acids, their physiology and metabolism

Synthesis and cytotoxic activity of a series of bile acid derivatives

The new conjugates of selected bile acids (hyocholic (2), deoxycholic (3), hyodeoxycholic (4) and 12-ketocholic (5) acids) with ethyl 11-aminoundecanoate 7, 8, 11, and 13 were synthesized. The conjugation reaction was carried out in ethyl acetate in the presence of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) and triethylamine. Under the same experimental conditions, the conjugation reaction involving ethyl 6-aminohexanoate resulted in formation of a conjugate 9 only in the case of deoxycholic acid (3) in addition to the unexpected ethyl ester 10. In the case of the other bile acids (cholic (1), hyodeoxycholic (4) and 12-ketocholic (5) acids) only an unexpected ester formation took place giving esters 6, 12, and 14. Cytotoxic activity against four tumor cell lines (human breast adenocarcinoma ER-, MDA-MB-231; breast adenocarcinoma ER+, MCF-7; cervix epiteloid carcinoma, HeLa S-3; and prostate cancer, PC-3) was evaluated. Conjugate 8 showed strong activity against HeLa S-3 and conjugate 11 for PC-3. Ethyl ester of 12-ketocholic acid 14 showed very strong antiproliferative activity against MCF-7 and HeLa S-3

Estimation of chromatographic lipophilicity of some D-homo androstene derivatives

Quantitative structure-retention relationship (QSRR) method was applied to study the chromatographic behaviour of D-homo-androstene derivatives 1-7. Retention constants (RM 0) of the analysed derivatives were determined by reversed-phase high-performance thin-layer chromatography (RP HPTLC) on C18 plates by using four mobile phase mixtures: methanol-water, acetone-water, acetonitrile-water, and dioxane-water. Correlation analysis based on multiple regression method was applied in order to model chromatographic retention by means of nine different lipophilicity descriptors (logP). The developed QSRR models were cross-validated and high-quality validation parameters were obtained by leave-one-out method. It was found that the derived QSRR models have a good predictive ability. [Projekat Ministarstva nauke Republike Srbije, br. 172012 i br. 172014

Antioxidant and cytotoxic activity of mono- and bissalicylic acid derivatives

A simple synthesis of mono- and bis-salicylic acid derivatives 1-10 by the transesterification of methyl salicylate (methyl 2-hydroxybenzoate) with 3-oxapentane-1,5-diol, 3,6- dioxaoctane-1,8-diol, 3,6,9-trioxaundecane-1,11-diol, propane-1,2-diol or 1-aminopropan- 2-ol in alkaline conditions is reported. All compounds were tested in vitro on three malignant cell lines (MCF-7, MDA-MB-231, PC-3) and one non-tumor cell line (MRC- 5). Strong cytotoxicity against prostate PC-3 cancer cells expressed compounds 3, 4, 6, 9 and 10, all with the IC50 less than 10 μmol/L, which were 11-27 times higher than the cytotoxicity of antitumor drug doxorubicin. All tested compounds were not toxic against the non-tumor MRC-5 cell line. Antioxidant activity of the synthesized derivatives was also evaluated. Compounds 2, 5 and 8 were better OH radical scavengers than commercial antioxidants BHT and BHA. The synthesized compounds showed satisfactory scavenger activity, which was studied by QSAR modeling. A good correlation between the experimental variables IC50 DPPH and IC50 OH and MTI (molecular topological indices) molecular descriptors and CAA (accessible Connolly solvent surface area) for the new compounds 1, 3, and 5 was observed