Phosphorus-nitrogen compounds: part 53-synthesis, characterization, cytotoxic and antimicrobial activity, DNA interaction and molecular docking studies of new mono- and dispirocyclotriphosphazenes with pendant arm(s).

Mono-/dispirocyclotriphosphazenes with pendant arm(s) are robust, but they are less investigated inorganic ring systems. In this study, a series of mono (3 and 4)- and dispirocyclotriphosphazenes with 4-chloro-benzyl pendant arm(s) (13-16) was obtained from the Cl exchange reactions of hexachlorocyclotriphosphazene with sodium (N-benzyl)aminopropanoxides (1 and 2). When compound (3) reacted with excess pyrrolidine, morpholine, tetra-1,4-dioxa-8-azaspiro[4,5]decane (DASD) and piperidine, the fully substituted monospirocyclotriphosphazenes (7, 9, 10 and 12) occurred. But, the reactions of 4 with excess piperidine and morpholine produced the gem-piperidino (5)- and morpholino (6)-substituted monospirocyclotriphosphazenes, whereas the reactions of 4 with excess pyrrolidine and DASD gave the fully substituted monospirocyclotriphosphazenes (8) and (11). However, it should be indicated that these derivatives were obtained to be used for the investigation of their spectral, stereogenic and biological properties. The structures of 5, 7 and 14 were determined crystallographically. X-ray data of 5 and 14 displayed that both of compounds were chiral in solid state, and their absolute configurations were assigned as R and RR. Additionally, the antimicrobial activities of phosphazenes were investigated. Minimum inhibitory concentrations, minimal bacterial concentrations and minimum fungicidal concentrations of phosphazenes were determined. The interactions of phosphazenes with plasmid DNA were evaluated by agarose gel electrophoresis. The cytotoxic activities of compounds were studied against L929 fibroblast and DLD-1 colon cancer cells. In addition, density functional theory calculations of 5, 7 and 14 were reported, and their molecular docking studies with DNA, E. coli DNA gyrase and topoisomerase IV were presented.

Synthesis and spectroscopic properties of (N/O) mono- and dispirocyclotriphosphazene derivatives with benzyl pendant arms: study of biological activity.

The Cl replacement reactions of hexachlorocyclotriphosphazene (trimer; N 3 P 3 Cl 6 ) with sodium (N-benzyl)- aminopropanoxides (1 and 2) produced monospiro- (3 and 4), cis-, and trans-dispirocyclotriphosphazenes (13-16). The monospiro tetrakis-aminocyclotriphosphazenes (5-12) were obtained by the Cl substitutions of 3 and 4 with different secondary amines. The cis- (13 and 14) and trans-dispirophosphazenes (15 and 16) possessed 2 chiral P centers, and they were able to present meso and racemic forms, respectively. Moreover, the structures of compounds 5 and 14 were designated using X-ray data. The absolute configuration of compound 14 was found as SR in the solid state. Analytical and spectroscopic data of the phosphazenes were consistent with their suggested structures. Antimicrobial activities of the benzyl-pendant-armed cyclotriphosphazenes were scrutinized against G(+) and G(-) bacteria and yeast strains. The bacterium most affected by the synthesized compounds was Pseudomonas aeruginosa . Minimum inhibitory concentrations and minimal bacterial concentrations were in the range of 125-500 µM. Interactions between the phosphazenes (3-12 and 15) and plasmid DNA were studied with agarose gel electrophoresis. The phosphazene- DNA interaction studies of the cyclotriphosphazenes revealed that phosphazenes 3, 4, and 15 had a substantial effect on supercoiled DNA by cleavage of the double helix.

Phosphorus-nitrogen compounds- (Part 50): correlations between structural parameters for cylophosphazene derivatives containing ferrocenyl pendant arm(s).

The results of a systematic study of spiro -cyclotri/tetraphosphazenes with ferrocenyl pendant arm on the basis of correlation between structural parameters were presented. The main parameters were obtained from Xray crystallography and 31P NMR results in order to investigate the relationship between the δ P spiro shift values and endocyclic and exocyclic NPN bond angles, and electron density transfer parameters. Structural parameters derived from 11 types of the ferrocenyl cyclophosphazene derivatives with 5- to 7-membered spiro -rings introduced to the literature from our research group were studied and compared with each other.

Phosphorus-nitrogen compounds (Part 51): the relationship between spectroscopic and crystallographic data of mono- and di- spiro cyclophosphazene derivatives with 4-fluoro/nitrophenylmethyl pendant arm/arms.

A great wealth of structural information about phosphazenes can be gleaned from the combined spectroscopic and crystallographic data. When data from 31P NMR spectroscopy and X-ray crystallography are put together like pieces in a puzzle, a number of correlations can be obtained for phosphazene derivatives. A systematic study concerning the correlations among the structural parameters (e.g., 31P NMR data, endocyclic/exocyclic NPN bond angles and bond lengths) revealed some characteristics of mono- and di- spiro cyclophosphazene derivatives bearing 4-fluoro/nitrophenylmethyl pendant arm/arms. These correlations include the relationship between the δ P spiro shifts, the values of electron density transfer parameters Δ(P-N), and the endocyclic and exocyclic NPN bond angles of the cyclophosphazenes. The structural parameters were compared with each other for 19 compounds of 5 different architectural types of cyclophosphazenes with 5- to 7-membered spiro -rings.

Phosphorus-nitrogen compounds: part 30. Syntheses and structural investigations, antimicrobial and cytotoxic activities and DNA interactions of vanillinato-substituted NN or NO spirocyclic monoferrocenyl cyclotriphosphazenes.

The gradual Cl replacement reactions of NN (1-3) or NO spirocyclic monoferrocenyl cyclotriphosphazenes (4 and 5) with the potassium salt of 4-hydroxy-3-methoxybenzaldehyde (potassium vanillinate) resulted in the mono (1a-5a), geminal (gem-1b-5b), non-geminal (cis-5b and trans -1b-4b), tri (1c, 3c-5c) and tetra-vanillinato-substituted phosphazenes (1d-5d). All the phosphazene derivatives have stereogenic P-center(s), except tetra-substituted ones. The vanillinatophosphazenes have reversible voltammograms with one-electron anodic and cathodic peaks which are attributed to ferrocenyl redox probe. The structures of the new phosphazene compounds were determined by FTIR, MS, (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectral data. The solid-state structure of cis -5b was examined by single-crystal X-ray diffraction techniques. In addition, the compounds were tested in HeLa cancer cell lines using MTT assay. The 12 phosphazene derivatives were screened for antimicrobial activity, and 3c was very effective against S. aureus even at 4.88 µM concentration, taking into account the MIC values. Besides, interactions between the phosphazenes and pBR322 plasmid DNA were also investigated.

Phosphorus-nitrogen compounds. Part 23: syntheses, structural investigations, biological activities, and DNA interactions of new N/O spirocyclotriphosphazenes.

The Schiff base compounds (1 and 2) are synthesized by the condensation reactions of 2-furan-2-yl-methylamine with 2-hydroxy-3-methoxy- and 2-hydroxy-5-methoxy-benzaldehydes and reduced with NaBH(4) to give the new N/O-donor-type ligands (3 and 4). The monospirocyclotriphosphazenes containing 1,3,2-oxazaphosphorine rings (5 and 6) are prepared from the reactions of N(3)P(3)Cl(6) with 3 and 4, respectively. The reactions of 5 and 6 with excess pyrrolidine, morpholine, and 1,4-dioxa-8-azaspiro [4,5] decane (DASD) produce tetrapyrrolidino (5a and 6a), morpholino (5b and 6b), and 1,4-dioxa-8-azaspiro [4,5] deca (5c and 6c) spirocyclotriphosphazenes. The structural investigations of the compounds are examined by (1)H, (13)C, (31)P NMR, DEPT, HSQC, and HMBC techniques. The solid-state structures of 5, 5a, and 6 are determined using X-ray crystallography. The compounds 5a, 5b, 5c, 6a, 6b, and 6c are subjected to antimicrobial activity against six patojen bacteria and two yeast strains. In addition, interactions between these compounds and pBR322 plasmid DNA are presented by agarose gel electrophoresis.

Phosphorus-nitrogen compounds. 21. Syntheses, structural investigations, biological activities, and DNA interactions of new N/O spirocyclic phosphazene derivatives. The NMR behaviors of chiral phosphazenes with stereogenic centers upon the addition of chiral solvating agents.

The reactions of hexachlorocyclotriphosphazatriene, N(3)P(3)Cl(6), with N/O-donor-type N-alkyl (or aryl)-o-hydroxybenzylamines (1a-1e) produce mono- (2a-2e), di- (3a-3d), and tri- (4a and 4b) spirocyclic phosphazenes. The tetrapyrrolidino monospirocyclic phosphazenes (2f-2i) are prepared from the reactions of partly substituted compounds (2a-2d) with excess pyrrolidine. The dispirodipyrrolidinophosphazenes (3e-3h) and trispirophosphazenes (3i-3k) are obtained from the reactions of trans-dispirophosphazenes with excess pyrrolidine and sodium (3-amino-1-propanoxide), respectively. Compounds 3a-3d have cis and trans geometric isomers. Only the trans isomers of these compounds are isolated. Compounds 3a-3h have two stereogenic P atoms. They are expected to be in cis (meso) and trans (racemic) geometric isomers. In the trans trispiro compounds (3i-3k), there are three stereogenic P atoms. They are expected to be in racemic mixtures. The stereogenic properties of 3a-3k are confirmed by (31)P NMR spectroscopy upon the addition of the chiral solvating agent; (S)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol. The molecular structures of 3i-3k, 4a, and 4b look similar to a propeller, where the chemical environment of one P atom is different from that of others. Additionally, 4a and 4b are also expected to exist as cis-trans-trans and cis-cis-cis geometric isomers, but both of them are found to be in cis-trans-trans geometries. The solid-state structures of 2a, 2e, 2f, 3e, and 3f are determined by X-ray crystallography. The compounds 2f-2i, 3e-3i, and 3k are screened for antibacterial activity against gram-positive and gram-negative bacteria and for antifungal activity against yeast strains. These compounds (except 3f) have shown a strong affinity against most of the bacteria. Minimum inhibitory concentrations (MIC) are determined for 2f-2i, 3e-3i, and 3k. DNA binding and the nature of interaction with pUC18 plasmid DNA are studied. The compounds 2f-2i, 3e-3i, and 3k induce changes on the DNA mobility. The prevention of BamHI and HindIII digestion (except 2g) with compounds indicates that the compounds bind with nucleotides in DNA.

Phosphorus-nitrogen compounds. 18. Syntheses, stereogenic properties, structural and electrochemical investigations, biological activities, and DNA interactions of new spirocyclic mono- and bisferrocenylphosphazene derivatives.

The reactions of hexachlorocyclotriphosphazatriene, N(3)P(3)Cl(6), with mono- (1 and 2) and bisferrocenyldiamines (3-5), FcCH(2)NH(CH(2))(n)NHR(1) (R(1) = H or FcCH(2)-), produce mono- (6 and 7) and spirocyclic bisferrocenylphosphazenes (8-10). The fully substituted phosphazenes (11-15 and 18-21) are obtained from the reactions of corresponding partly substituted phosphazenes (6-10) with excess pyrrolidine and NH(2)(CH(2))(3)ONa, respectively. The reactions of 6 with 1-aza-12-crown-4 afford geminal (16) and tris (17) crown ether-substituted phosphazenes. The structural investigations of the compounds have been verified by elemental analyses, mass spectrometry, Fourier transform IR, (1)H, (13)C, and (31)P NMR, and DEPT, COSY, HETCOR, and HMBC techniques. The crystal structures of 7, 10, 11, and 15 have been determined by X-ray crystallography. In 16 and 17, there are one and two stereogenic P atoms, respectively, and they are expected to be in enantiomeric mixtures. The structures of 18-21 look similar to a propeller. In 20 and 21, there are two stereogenic P atoms, and they exist as cis (meso; 20a and 21a) and trans (racemic; 20b and 21b) geometric isomers, according to the chiral solvating agent (S)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol experiments. Moreover, the compounds 18 and 19 have three stereogenic P atoms, and they exist as enantiomeric mixtures. Cyclic voltammetric investigations of compounds 6-21a reveal that ferrocene redox centers undergo oxidation concurrently at the same potential with basically reversible peaks, and these compounds appear to be quite robust electrochemically. The compounds 11-15 have been screened for antibacterial activity against gram positive and gram negative bacteria and for antifungal activity against yeast strains.The compounds 11, 12, 14, and 15 are evaluated for antituberculosis activity against reference strain Mycobacterium tuberculosis H37Rv (ATCC 27294). Interactions between compounds 11-15 and pBR322 plasmid DNA are studied by agarose gel electrophoresis. These compounds induce conformational changes in the DNA helix.

Phosphorus-nitrogen compounds. 14. Synthesis, stereogenism, and structural investigations of novel n/o spirocyclic phosphazene derivatives.

The reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6, with N/O donor-type N-alkyl-o-hydroxybenzyl- and o-hydroxynaphthylamines result in novel mono- (3a, 4a and 4b), di- (5a and 5b), and tri- (3b, 6a, and 6b) spirocyclic phosphazene derivatives. The tetrakis-pyrrolidinophosphazene, 3b, has been obtained from the reaction of partly substituted compound 3a with the excess pyrrolidine in tetrahydrofuran. The relationship between the endocyclic NPN (alpha) and exocyclic NPO (alpha') bond angles of the analogous spirocyclic phosphazenes with the deltaP shifts of NPO phosphorus atoms have been presented. It was observed that there is a linearity between alpha angles and deltaP shifts, while no linear relationship has been observed for alpha' angles. In addition, we have found the correlation between Delta(P-N) and deltaNPO shifts, which implies a linear relationship. Delta(P-N)=(a-b), where a and b are the average lengths of two adjacent P-N bonds. The structural investigations of all of the compounds have been made by elemental analyses; mass spectrometry; Fourier transform infrared spectroscopy; one-dimensional 1H, 13C, and 31P NMR; distortionless enhancement by polarization transfer; and two-dimensional correlation spectroscopy, heteronuclear shift correlation, and heteronuclear multiple-bond correlation homo- and heteronuclear correlation techniques. The solid-state structures of 3a, 4a, 4b, and 5a have been determined by X-ray crystallographic techniques. The asymmetric units of compounds 3a and 4a contain two independent molecules, and 3a has strong intermolecular N-H...N hydrogen bonds linking three phosphazene rings. The molecular structure of 6a looks like a propeller where the chemical environment of P1 is different from that of P2 and P3. On the other hand, compounds 5a and 5b are expected to exist as cis- or trans-geometric isomers and to be in cis (meso) or trans (racemic) configurations. The crystallographic and preliminary chiral solvating agents results show that both of them are trans (racemic). In addition, 6a and 6b are also expected to exist as cis-trans-trans- and cis-cis-cis-geometric isomers; both of them are found to be in cis-trans-trans geometries. According to the two-dimensional spectroscopic data, the possible conformations of 3a and 4a in CDCl3 are the same with the solid-state structures.