Új androsztán- és ösztránvázas heterociklusok szintézise = Synthesis of novel heterocycles in the androstane and estrane series

A támogatott időszakban szteránvázas O-, N- és/vagy P-atomokat tartalmazó heterociklusos származékok szintézisét végeztük el. Androszt-5-én váz D-gyűrűjéhez kondenzált arilpirazolinokat és izoxazolidineket állítottunk elő intramolekuláris 1,3-dipoláris cikloaddícióval. Értelmeztük a reakciók mechanizmusát és sztereoszelektivitását. Az előállított vegyületek számos képviselője jelentős mértékű in vitro citosztatikus aktivitást mutatott különböző rosszindulatú ráksejt vonalakon. Spirociklusos és kondenzált dioxafoszforinánok szintézisét valósítottuk meg az ösztron és a 4-androsztén sorban. NMR-spektroszkópia segítségével tanulmányoztuk a P-tartalmú hattagú heterogyűrűk oldatbeli konformációját. Új típusú izokinuklidin származékokat állítottunk elő ösztránvázas kiindulási anyagból, melynek során egyedi, az irodalomban még nem ismert reakciótípust ismertünk fel. Androsztén- és ösztránvázas triazolok és tetrazolok szintézisét végeztük el intermolekuláris Cu(I)-katalizált azid-alkin cikloaddícióval. Néhány vegyület közepes, illetve jó sejtosztódás-gátlást mutatott különböző ráksejt vonalakon. | During the supported period the syntheses of O-, N- and/or P-containing steroidal heterocyclic derivatives were carried out. Arylpyrazolines and isoxazolidines in the androst-5-ene series were prepared by 1,3-dipolar cycloaddition. The mechanism and stereoselectivity of the reactions were elucidated. Several compounds exerted marked in vitro antiproliferative activity on different malignant human cell lines. Spirocyclic and condensed dioxaphosphorinanes in the estrone and androst-4-ene series were also synthetized. The stereostructures of the six-membered P-hetero ring in solution were investigated by NMR methods. Novel types of isoquinuclidine derivatives in the estrone series were obtained, during which a unique reaction-type was recognized. The synthesis of novel triazoles and terazoles were carried out in the andostene and estrone series using Cu(I)-catalyzed azide-alkyne cycloaddition. Numerous compounds displayed moderate or good cell-growth inhibition

Szteránvázas vegyületek kutatása = Research of steroids

A szteránváz D-gyűrűjéhez kondenzált heterociklusok farmakológiailag jelentős vegyületek. A beszámolási időszakban az androszt-5-én vázhoz 17?-helyzetben kondenzált, két heteroatomot tartalmazó ciklusokat építettünk ki. Az N-fenil-, és az N-szubsztituált-fenil-2-oxazolidonokat a szteránvázhoz fűződő ?,?-haloalkil-N-ariluretánok alkalikus közegű szolvolízisével végeztük. A folyamat egy (N-5) szimbólummal jellemezhető szomszédcsoport részvétel. A 21-hidroximetilidén-pregn-5-én-20-on fenilhidrazinnal és annak szubsztituált származékaival végzett átalakítása két regioizomer N-fenil-pirazolhoz vezet. Arilpirazolin és izoxazolidin származékok előállítását 1,3-dipoláris cikloaddicióval sikerült megvalósítani az androszt-5-én sorban. A folyamat mechanizmusát és sztereoszelektivitását számításokkal sikerült alátámasztani. A 13?-ösztron sorban endo-, és exo-ciklusos ketonok kialakítását sikerült megvalósítani, melyek nitriliminnel végzett 1,3-dipoláris cikloaddícója regioizomer pirazolinokhoz vezetett. Az elállított vegyületek jelentős része jelentős antiproliferativ hatásúnak bizonyult. | Steroids bearing heterocycles attached to the D-ring of the steroid nucleus have been of pharmaceutical interest. During the supported period we carried out synthesis of steroidal two heteroatom-containing heterocycles at position 17? of androst-5-en-3?-ol. For the synthesis of the N-phenyl-, and N-(substituted-phenyl)-2-oxazolidone ring we chose cyclization of the steroidal ?,?-haloalkyl-N-arylurethanes in alkaline media. The cyclization takes place with (N-5) neighboring group participation. The reaction of 21-hydroxymethylidenepregn-5-en-20-one with phenylhydrazine, or p-substituted phenylhydrazines affords two regioisomer steroidal N-phenylpyrazolyl derivatives. Arylpyrazolynes and isoxazolidines in the androst-5-ene series were prepared by 1,3-dipolar cycloaddition. The mechanism and stereoselectivity of the reactions were elucidated. Effective syntheses of endo- and exocyclic ?,?-unsaturated ketones were carried out in the 13?-estrone series. The 1,3-dipolar cycloadditions of 15,16-unsaturated ketones with nitrilimines stereoselectively furnished two regioisomers of new condensed pyrazolynes. Several compounds exerted marked in vitro antiproliferative activity on different malignant human cell lines

Szteránvázas vegyületek szintézise = Synthesis of Steroid Compounds

Az érdeklődésünk 2003-2005 között a cisz C/D gyűrűs 3-metoxi-, illetve a 3-benziloxi-ösztra-17-on származékok felé fordult. A kívánt 13α-D-szeko-ösztron-aldehid előállítására a legjobbnak a 16-jódmetil származékok bizonyultak, amelyek a kívánt 13α-szeko-ösztron-aldehiddé voltak alakíthatók. - Az aldehid csoport, valamint az olefin oldallánc lehetőséget adott egy Prins típusú ciklizációra. Ennek eredményeként a hattagú D-gyűrűs 3-metoxi-, illetve 3-benziloxi-D-homo-ösztronhoz jutottunk. - A 13β-D-szeko-ösztron-aldehid Grignard reakcióval, majd az azt követő intramolekulás Heck reakcióval hét-, nyolc-, illetve kilenctagú D-gyűrűt tartalmazó ösztron származékokhoz vezetett. - A 13α-, és a 13β-D-szeko-ösztron-aldehidek intramolekulás reakcióval gyűrűs nitronokká alakultak, amelyek N-fenil-maleinimiddel 1,3-dipoláros cikloaddícióval halogént tartalmazó D-homo-ösztron heterociklusokhoz vezettek. -Egy 9,13-áthidalt D-szeko-ösztron alkaloid típushoz jutottunk a 13β-szeko-ösztron-aldehid anilinnel, és szubsztituált anilinekkel, Lewis-sav jelenlétében végzett reakciójával. Az új D-szeko-ösztron-izokinuklidin keletkezése1,5-hidrid-ion vándorlással értelmezhető. - Új utat találtunk a transz-3β-hidroxi-16,17-szeko-pregna-5,17(20)-dién-16-al előállítására. Az így nyert szeko-szteroidban a formil csoport és a telítetlen oldallánc alkalmassá teszi a szteránvázhoz kondenzált heterociklusok kialakítását. | During the research period 2003-2005 we were interested in compounds with an inverted configuration at C-13, i.e. derivatives of 13α-estrane-17-on-3-ethers containing a cis junction of rings C and D. With the aim of preparing the 13α-D-seco-estrone aldehyde, the 16-iodomethyl derivatives were the starting materials for the fragmentation. - The presence of the olefinic moiety and the formyl group makes the molecules suitable for intramolecular Prins-type reaction. The result is the 3-methoxy-, and 3-benzyloxyestrone containing a six-membered ring D. - A new type of steroids with seven-, eight-, or nine-membered D-ring have been synthesized from 13β-D-seco-estrone aldehyde derivative by a Grignard and an intramolecular Heck reaction. - Starting from the 13α-, and 13β-D-seco-estrone aldehyde by 1,3-dipolar cycloaddition reactions with N-phenylmaleinimide stereoselectively furnished halogen-containing condensed heterocyclic D-homosteroids. - Unique 9,13-bridged D-seco-estrone alkaloids have been synthesized starting from 13β-seco-estrone aldehyde with aniline in the presence of Lewis acids. - A new synthetic route was developed for the preparation of trans-3β-hydroxy-16,17-seco-pregna-5,17(20)-dien-16-al. - Starting from the trans-3β-acetoxy-16,17-seco-pregna-5,17(20)-dien-16-al and using aniline with BF3.OEt2, different tetrahydroquinoline derivatives via Diels-Alder reaction were formed

Estradiol-Based Salicylaldehyde (Thio)semicarbazones and Their Copper Complexes with Anticancer, Antibacterial and Antioxidant Activities

A series of novel estradiol-based salicylaldehyde (thio)semicarbazones ((T)SCs) bearing (O,N,S) and (O,N,O) donor sets and their Cu(II) complexes were developed and characterized in detail by 1H and ¹³C nuclear magnetic resonance spectroscopy, UV–visible and electron paramagnetic resonance spectroscopy, electrospray ionization mass spectrometry and elemental analysis. The structure of the Cu(II)-estradiol-semicarbazone complex was revealed by X-ray crystallography. Proton dissociation constants of the ligands and stability constants of the metal complexes were determined in 30% (v/v) DMSO/H2O. Estradiol-(T)SCs form mono-ligand complexes with Cu(II) ions and exhibit high stability with the exception of estradiol-SC. The Cu(II) complexes of estradiol-TSC and its N,N-dimethyl derivative displayed the highest cytotoxicity among the tested compounds in MCF-7, MCF-7 KCR, DU-145, and A549 cancer cells. The complexes do not damage DNA according to both in vitro cell-free and cellular assays. All the Cu(II)-TSC complexes revealed significant activity against the Gram-positive Staphylococcus aureus bacteria strain. Estradiol-TSCs showed efficient antioxidant activity, which was decreased by complexation with Cu(II) ions. The exchange of estrone moiety to estradiol did not result in significant changes to physico-chemical and biological properties

Substitutional Diversity-Oriented Synthesis and In Vitro Anticancer Activity of Framework-Integrated Estradiol-Benzisoxazole Chimeras

Hybridization of steroids and other pharmacophores often modifies the bioactivity of the parent compounds, improving selectivity and side effect profile. In this study, estradiol and 3′-(un)substituted benzisoxazole moieties were combined into novel molecules by structural integration of their aromatic rings. Simple estrogen starting materials, such as estrone, estradiol and estradiol-3-methylether were used for the multistep transformations. Some of the heterocyclic derivatives were prepared from the estrane precursor by a formylation or Friedel–Crafts acylation—oximation—cyclization sequence, whereas others were obtained by a functional group interconversion strategy. The antiproliferative activities of the synthesized compounds were assessed on various human cervical, breast and prostate cancer cell lines (HeLa, MCF-7, PC3, DU-145) and non-cancerous MRC-5 fibroblast cells. Based on the primary cytotoxicity screens, the most effective cancer-selective compounds were selected, their IC50 values were determined and their apoptosis-inducing potential was evaluated by quantitative real-time PCR. Pharmacological studies revealed a strong structure–function relationship, where derivatives with a hydroxyl group on C-17 exhibited stronger anticancer activity compared to the 17-acetylated counterparts. The present study concludes that novel estradiol-benzisoxazole hybrids exert remarkable cancer cell-specific antiproliferative activity and trigger apoptosis in cancer cells

A Click Approach to Novel D-Ring-Substituted 16α-Triazolylestrone Derivatives and Characterization of Their Antiproliferative Properties

A simple and efficient synthesis of novel, D-ring substituted estrone derivatives containing a 16α-triazolyl moiety is described. Two epimeric azido alcohols (16α-azido-17α-hydroxy and 16α-azido-17β-hydroxy) of estra-1,3,5(10)-triene-3-methyl ether were prepared, followed by copper(I)-catalyzed azide-alkyne cycloaddition with various terminal alkynes. The steroidal triazoles were obtained in high yields and their activities against three human cancer cell lines (HeLa, MCF7 and A431) were screened. The most effective analogs were submitted to additional experiments in order to characterize their antiproliferative properties. As evidenced by flow cytometry, the selected steroids induced a disturbance in the HeLa cell cycle in a concentration- and exposure-dependent manner, through an increase of the hypodiploid population (subG1) and a cell cycle arrest in the G2/M phase. A noncancerous human fibroblast cell line (MRC5) was used to determine the selectivities of these compounds. Fluorescent microscopy after Hoechst 33258 - propidium iodide (HOPI) double staining revealed nuclear condensation and disturbed cell membrane integrity. The enhanced activities of caspase-3 and caspase-9 without activation of caspase-8 in the treated cells indicated the activation of the intrinsic pathway of apoptosis. The levels of cell cycle regulators (CDK1, cyclin B1/B2 and cdc25B) were decreased and the ratio Bax/Bcl-2 was increased 24 h after the treatment of HeLa cells (determined at an mRNA level by means of an RT-PCR technique). Under the same conditions, two agents elicited substantially increased degrees of phosphorylation of stathmin, as evidenced by Western blotting. The presented results demonstrate that these steroids can be regarded as appropriate structural scaffolds for the design and synthesis of further steroid analogs as innovative drug candidates with good efficacy.</p

Synthesis and conversion of primary and secondary 2-aminoestradiols into A-ring-integrated benzoxazolone hybrids and their in vitro anticancer activity

Hybrid systems are often endowed with completely different and improved properties compared to their parent compounds. In order to extend the chemical space toward sterane-based molecular hybrids, a number of estradiol-derived benzoxazol-2-ones with combined aromatic rings were synthesized via the corresponding 2-aminophenol intermediates. 2-Aminoestradiol was first prepared from estrone by a two-step nitration/reduction sequence under mild reaction conditions. Subsequent reductive aminations with different arylaldehydes furnished secondary 2-aminoestradiol derivatives in good yields. The proton dissociation processes of the aminoestradiols were investigated in aqueous solution by UV-visible spectrophotometric titrations to reveal their actual chemical forms at physiological pH. The determined pK(1) and pK(2) values are attributed to the (+)NH(3) or (+)NH(2)R and OH moieties, and both varied by the different R substituents of the amino group. Primary and secondary 2-aminoestradiols were next reacted with carbonyldiimidazole as a phosgene equivalent to introduce a carbonyl group with simultaneous ring-closure to give A-ring-fused oxazolone derivatives in high yields. The novel aminoestradiols and benzoxazolones were subjected to in vitro cytotoxicity analysis and were found to exert cancer cell specific activity