Photophysical studies of tin(IV)-protoporphyrin: Potential phototoxicity of a chemotherapeutic agent proposed for the prevention of neonatal jaundice

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.14.5249· OSTI ID:5642218

Land, E J; McDonagh, A F; McGarvey, D J; Truscott, T G ^[1]

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1. Paterson Institute for Cancer Research, Manchester (England)

The strongly light-absorbing metalloporphyrin tin(IV)-protoporphyrin IX (SnPP) is currently being considered as a chemotherapeutic agent for preventing severe hyperbilirubinemia in newborns, a condition usually treated by phototherapy with visible light. To assess the potential phototoxicity of SnPP the authors studied the photophysics of the drug in aqueous and nonaqueous solutions using laser flash photolysis and pulse radiolysis. Quantum yields for formation of triplet-state excited SnPP were measured, along with triplet lifetimes and extinction coefficients. In addition, they measured quantum yields for the SnPP-photosensitized formation of singlet oxygen in MeO{sup 2}H and in {sup 2}H{sub 2}O containing cetyltrimethylammonium bromide, using a time-resolved luminescence technique. Quantum yields for formation of triplet SnPP from monomeric ground-state SnPP are high, and triplet lifetimes are long. SnPP-photosensitized formation of singlet oxygen in aqueous and nonaqueous solvents was confirmed by the detection of the characteristic luminescence at 1270 nm. These observations suggest that cutaneous photosensitivity arising from singlet-oxygen damage is likely to be an undesirable side-effect of SnPP therapy.

• OSTI ID: 5642218
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:14; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AGE GROUPS
AQUEOUS SOLUTIONS
BODY
CARBOXYLIC ACIDS
CHEMOTHERAPY
CHILDREN
COMPLEXES
DISPERSIONS
HEAVY WATER
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INFANTS
JAUNDICE
LUMINESCENCE
MIXTURES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PATHOLOGICAL CHANGES
PHOTOSENSITIVITY
PIGMENTS
PORPHYRINS
PROTOPORPHYRINS
SENSITIVITY
SIDE EFFECTS
SKIN
SOLUTIONS
SOLVENTS
SYMPTOMS
THERAPY
TIN COMPLEXES
TOXICITY
WATER