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(5R)-Cleistenolide and a few related analogues have been synthesized starting from d-glucose. The key steps of the synthesis included a Z-selective Wittig olefination and an intramolecular Mitsunobu reaction with an inversion of configuration at the C-5 position. In vitro antiproliferative activity of synthesized compounds was tested on a panel of eight human tumour cells and against a single normal cell line (MRC-5). The majority of tested compounds showed strong antiproliferative effects on certain human tumour cells and all of them showed negligible toxicity to normal foetal lung fibroblasts (MRC-5). The most active compound obtained in this work is lactone 5, which in MDA-MB 231 cell culture showed the same activity as doxorubicin (IC50 0.09 μM). Strong antiproliferative activities of analogues 2, 5 and 6 were recorded in the K562 cell line (IC50 0.21, 0.34 and 0.33 μM, respectively), in which they showed very similar activities to doxorubicin (IC50 0.25 μM). A performed SAR study revealed that a change in the stereochemistry at the C-5 position may increase the activity of resulting stereoisomers.

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]

Biological investigation was conducted to study in vitro changes in morphological properties and metabolic activity of human continuous cell lines after treatment with the morphogenetic field hologram information (the field). We used human tumor cell lines, including cervical (HeLa) and lung cancer (A549), as well as one normal fetal lung fibroblasts cell line (MRC-5) to investigate the effect of such treatment. Metabolic activity of investigated cell lines was evaluated by MTT assay. Results showed that MRC-5 cells exposed 3 h to the field had 50% increases in metabolic activity 48 h after treatment in comparison to untreated control cells. Similar but lower effect was observed in both tested tumor cell lines. Changes in cells depended also on the exposure time. Morphology of the cells was examined by visual observations using light microscopy. Metabolic activity was evaluated by MTT assay. Results of this study showed that application of the field has measurable influence on biological systems. [ABSTRACT FROM AUTHOR]