The Synthesis of Isomeric Dithymidyl-phosphorus(V)-meso-tetraphenylporphyrins

Phosphorus complexes of porphyrinoid macrocycles

Phosphorus complexes of porphyrinoids such as porphyrins, corroles, [Formula: see text]-fused porphyrins, [Formula: see text]-fused expanded porphyrins and expanded porphyrins can be prepared readily by treating the porphyrinoid with phosphorylating agents such as PX3, PX5and POX3(X [Formula: see text] Cl or Br) under standard reaction conditions. In phosphorus porphyrinoids, the phosphorus is generally high valent [Formula: see text]5 oxidation state and the coordination number is varied from four to six. The insertion of P(V) into porphyrinoids alters the structure and electronic properties of the macrocycle significantly. Specially, the phosphorus binding mode is different from one porphyrinoid to another. The oxophilicity nature of P(V) in P(V) porphyrinoids is very useful to change variety of axial ligands and also helps to synthesize multi-porphyrin arrays by axial bonding approach. This review summarizes the phosphorus complexes of five different porphyrinoids and discusses their structure and electronic properties as well as their applications in the synthesis of more elaborate P(V) porphyrinoid based architectures.

p-nitrobenzamide substituted phosphorus(V) porphyrins: synthesis and interactions with DNA

Four new phosphorus(V) porphyrins were designed and synthesized. The compounds were diaxially substituted with 4-nitrobenzamide. The axial ligands were attached to the P(V) center of the porphyrins through methylene linkers of different lengths. DNA titrations showed the expected porphyrin binding. When exposed to 532 nm laser light, which corresponds to the porphyrin Q band, the photosensitizers induced DNA nicking. Inhibition of the nicking by sodium azide suggested participation of singlet oxygen in the process. Photoexcitation with 305 nm laser light, which corresponds to absorption of 4-nitrobenzamide, also resulted in DNA damage. Due to the lack of electronic communication between the axial ligands and the porphyrin, the desired pathway of DNA cleavage was chosen by selecting a proper wavelength of the light used for photoexcitation. The activities of the porphyrins in photoinduced DNA nicking were very similar in both experiments: irradiation with 305 and 532 nm light, and were inversely correlated with the length of the linkers.

Phosphorus (V) porphyrin diaxially substituted with Leu-enkephalin

Synthesis of the first phosphorus (V) porphyrin-peptide conjugate was successfully accomplished. A biologically active peptide, leucine enkephalin, was constructed on the phosphorus atom of the 5,10,15,20-meso-tetraphenylporphinato dichlorophosphorus (V) chloride. The method involved solution phase peptide synthesis. The first C-terminal amino acid in the sequence of the peptide was axially attached to the porphyrin through a linker, 3-aminopropanol, and the remainder of leucine enkephalin was synthesized by subsequent additions of amino acids. Leucine enkephalin-P(V) porphyrin conjugate represents a new group of compounds, and its synthesis broadens potential applications of P(V) porphyrine, e.g. in photodynamic therapy.