Natural polyamines-linked cyclophosphazenes. Attempts at the production of more selective antitumorals

Phosphorus–nitrogen compounds. Part 42. The comparative syntheses of 2-cis-4-ansa(N/O) and spiro(N/O) cyclotetraphosphazene derivatives: spectroscopic and crystallographic characterization, antituberculosis and cytotoxic activity studies

Syntheses, structural properties and biological activities of ferrocenyl ansa- and spiro-cyclotetraphosphazenes were investigated.

Phosphorus-nitrogen compounds. Part 24. Syntheses, crystal structures, spectroscopic and stereogenic properties, biological activities, and DNA interactions of novel spiro-ansa-spiro- and ansa-spiro-ansa-cyclotetraphosphazenes

The reactions of octachlorocyclotetraphosphazene, N(4)P(4)Cl(8), with N(2)O(2) donor-type aminopodands (1a, 1b, 1g, and 1h) afforded two kinds of derivatives, namely, spiro-ansa-spiro (sas) (2a, 2b, 2g, and 2h) and ansa-spiro-ansa (asa) (3a and 3b) phosphazenes. The partly substituted sas phosphazenes (2a and 2b) reacted with excess pyrrolidine and morpholine in tetrahydrofuran to produce the tetrapyrrolidino (2c and 2d) and morpholino (2e and 2f) derivatives. The reactions of the asa phosphazenes (3a and 3b) with excess pyrrolidine and morpholine produced gem-2-trans-6-dichloropyrrolidinophosphazenes (3c and 3d) and -morpholinophosphazenes (3e and 3f). However, the fully substituted products were not obtained in these solvents. In addition, the expected fully substituted compound was not obtained from the reaction of 3a with excess pyrrolidine by standard or microwave-assisted methods. The reaction of the long-chain starting compound (1g) with N(4)P(4)Cl(8) gave sas (2g) and the interesting 2,6-ansa-spiro-bicyclo product (bicyclo-2,6-as; 4g), while the reaction of 1h with N(4)P(4)Cl(8) yielded only sas (2h). The structural investigations of the compounds were verified by elemental analyses, mass spectrometry, Fourier transform infrared, and DEPT, HSQC, HMBC, (1)H, (13)C, and (31)P NMR techniques. The crystal structures of 2b, 3a, 3b, 3e, and 4g were determined by X-ray crystallography. Compounds 2a-2h, 3a-3f, and 4g had two stereogenic P atoms. Compound 3b had one enantiomer according to the Flack parameter, and 3f was a racemic mixture, as shown by chiral high-performance liquid chromatography and chiral-solvating-agent, (R)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol, experiments. Furthermore, compounds 2a, 2c, and 2d exhibited weak antibacterial activity against (G+) bacterium, and 3c and 3d displayed moderate antifungal activity against Candida tropicalis. Gel electrophoresis data demonstrated that 2e, 3c, and 3e promoted the formation of DNA cleavage. The prevention of BamHI digestion by 2a-2f and 3a-3f, except 2b and 2e, disclosed binding with GG nucleotides in DNA.

Phosphorus-nitrogen compounds. Part 20: Fully substituted spiro-cyclotriphosphazenic lariat (PNP-pivot) ether derivatives

The condensation reactions of partly substituted spiro-cyclotriphosphazenic lariat (PNP-pivot) ethers, N(3)P(3)[(o-NHPhO)(2)R]Cl(4) [where R=-CH(2)CH(2)- (1) and -CH(2)CH(2)OCH(2)CH(2)- (2)] with morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) produce fully substituted morpholino (3 and 4) and 1,4-dioxa-8-azaspiro[4,5]deca (5 and 6) phosphazenes. These are the new examples of the spiro-cyclophosphazenic lariat ether derivatives with N(2)O(x) (x=2 and 3) donor type containing 11- and 14-membered macrocycles. The solid state structures of 3, 5 and 6 have been determined by X-ray diffraction techniques. Compound 3 has intermolecular N-H...O hydrogen bond, compound 5 has intra- and intermolecular N-H...O hydrogen bonds, while compound 6 has intramolecular N-H...O and O-H...N and intermolecular N-H...O and O-H...O hydrogen bonds. The correlations of the endocyclic (alpha) and exocyclic (alpha') NPN bond angles with deltaP(spiro) values are investigated. The structural investigations of 3-6 have been verified by elemental analyses, MS, FTIR, (1)H, (13)C and (31)P NMR, DEPT and HETCOR techniques.

The structural and stereogenic properties of pentaerythritoxy-bridged cyclotriphosphazene derivatives: spiro–spiro, spiro–ansa and ansa–ansa isomers

Reactions of pentaerythritol with hexachlorocyclotriphosphazene, N3P3Cl6, and gem-disubstituted cyclotriphosphazene derivatives, N3P3Cl4R2 [R = Ph, NHBu(t) or (OCH2CF2CF2CH2O)0.5] gave a series of pentaerythritol-bridged derivatives linked spiro-spiro, spiro-ansa and ansa-ansa. The structures and stereogenic properties of the products were characterised by X-ray crystallography and 31P NMR spectroscopy on addition of the chiral solvating agent, (S)-(+)-2,2,2-trifluoro-1-(9-anthryl)ethanol. Molecules with spiro-spiro and spiro-ansa bridged gem-disubstituted cyclophosphazenes [R = Ph, NHBu(t) or (OCH2CF2CF2CH2O)0.5] are found to be chiral and exist as racemates. Molecules with ansa-ansa bridged cyclophosphazenes [R = Cl or (OCH2CF2CF2CH2O)0.5] have been characterised for the first time and are shown to have meso configurations. Analysis of crystal structure data shows that the six-membered chair form of the spiro rings and the eight-membered boat-chair form of the ansa rings in the bridged compounds are similar to analogous spiro and ansa exocyclic ring conformations of 1,3-propanedioxy-derivatives of cyclophosphazenes.

Selective Reactivity of the Phosphorus-Chlorine and Carbon-Chlorine Bonds in Cyclic Chlorocarbaphosphazenes: An Unusual Activation of a Carbon-Nitrogen Bond in Trialkylamines

Acyclic tertiary amines such as triethylamine and tri-n-propylamine used as HCl scavengers in nucleophilic substitution reactions of cyclic chlorocarbaphosphazenes [N(3)PC(2)Cl(4) (I) and N(3)P(2)CCl(5) (II)] with (CF(2))(n)()(CF(2)CH(2)OH)(2) [n = 0 (III) or 1 (IV)] are found to undergo a facile C-N bond cleavage with the regiospecific substitution of the dialkylamino groups on the ring carbon atoms of the carbaphosphazene. In the case of cyclic amines such as 1-methylpiperidine and 4-methylmorpholine, the cleavage was found to occur regiospecifically at the N-CH(3) bond, resulting in the ring substitution of the cyclic secondary amino group on the dicarbaphosphazene ring carbon atoms. The polyfluoro diol III forms a spirocyclic ring exclusively at the phosphorus site in compounds [CF(2)CH(2)O](2)PN(3)C(2)[N(C(2)H(5))(2)](2) (1), [CF(2)CH(2)O](2)PN(3)C(2)[N(C(3)H(7))(2)](2) (2), [CF(2)CH(2)O](2)PN(3)C(2)[NCH(2)(CH(2))(3)CH(2)](2) (3), and [CF(2)CH(2)O](2)PN(3)C(2)[N(CH(2))(2)O(CH(2))(2)](2) (5) along with the formation of carbon-substituted carbaphosphazenes, Cl(2)PN(3)C(2)[NCH(2)(CH(2))(3)CH(2)](2) (4) and Cl(2)PN(3)C(2)[N(CH(2))(2)O(CH(2))(2)](2) (6). Reaction of II with III in the presence of triethylamine affords the dispiro product [CF(2)CH(2)O)(2)](2)P(2)N(3)C[N(C(2)H(5))(2)] (7), which crystallizes in a polar orthorhombic space group, Cmc2(1). Upon refluxing of I or II with R(3)N (R = C(2)H(5), n-C(3)H(7)) in toluene, the amino-substituted carbaphosphazenes, Cl(2)PN(3)C(2)[N(C(2)H(5))(2)](2) (8), Cl(4)P(2)N(3)C[N(C(2)H(5))(2)] (9), and Cl(4)P(2)N(3)C[N(n-C(3)H(7))(2)] (10) are obtained in good yields. Hydrolysis of 8 leads to the formation of Cl(O)PN(H)N(2)C(2)[N(C(2)H(5))(2)](2) (11). When lithium salts of the fluoro diols III and IV are reacted with I or II in diethyl ether, the P-Cl bond is selectively substituted, yielding the spirocyclic [CF(2)CH(2)O](2)PN(3)C(2)Cl(2) (12), [CF(2)(CF(2)CH(2)O)(2)]PN(3)C(2)Cl(2) (13), [CF(2)CH(2)O](2)P(2)N(3)CCl(3) (14), and [(CF(2)CH(2)O)(2)](2)P(2)N(3)CCl (15). The C-Cl bonds in 12 and 14 were easily substituted by their reaction with 4-FC(6)H(4)XNa (X = O or S) to form [CF(2)CH(2)O](2)PN(3)C(2)[4-FC(6)H(4)O](2) (16) and [CF(2)CH(2)O](2)PN(3)C(2)[4-FC(6)H(4)S](2) (17). Reactions of 12 and 13 with (CH(3))(3)SiN(CH(3))(2) under mild conditions result in the elimination of (CH(3))(3)SiCl along with the formation of [CF(2)CH(2)O](2)PN(3)C(2)[N(CH(3))(2)](2) (18). The X-ray analyses of 13 and 18 represent the first examples of eight-membered spirocyclic phosphazenes. The thermal behavior of II, 9, 10, 14, and15 has also been investigated at 120 degrees C. Single-crystal X-ray diffraction studies were carried out for 1, 2, 7, 9-14, and 16-19, and these compounds are also characterized using IR, (1)H, (13)C, (19)F and (31)P NMR spectroscopy, MS, and elemental analysis.

Cross resistance and collateral sensitivity between cytotoxic drugs and radiation in two human bladder cell lines

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) test was employed as a means of studying the cross resistance and collateral sensitivities of two bladder cell lines able to grow in the presence of several antineoplastic drugs and/or despite the effects of radiotherapy. This cross resistance and collateral sensitivities were investigated in the context of two antineoplastic drugs (i.e. doxorubicin (an anthracycline) and vinorelbine (a Vinca alkaloid) and radiotherapy. The results show that cell lines able to grow in the presence of anticancer drugs develop a significant degree of resistance to antineoplastic compounds and may also develop resistance to radiotherapy. On the other hand, most cell lines treated first with radiotherapy develop a significant degree of resistance towards ionizing radiation and may also display increased sensitivity towards anticancer drugs. If these results obtained in vitro are clinically relevant, they may have important applications in the treatment of patients. Nevertheless, it will be necessary to validate the results on extensive series of chemo- and/or radioresistant cell lines exhibiting different mechanisms of resistance.