Antimicrobial photodynamic effect of extracts and oxoaporphine alkaloid isomoschatoline from Guatteria blepharophylla.
Photodynamic Therapy, a tumor therapy idealized at the beginning of the last century, emerges nowadays as a promising treatment alternative against infectious diseases. In this study we report a bioguided study of Guatteria blepharophylla phytoderivatives for antimicrobial PDT. Crude extracts and fraction from the species bark were obtained and further fractionated for substances isolation. All samples were evaluated in relation to their photophysical (absorbance and fluorescence) and photochemical properties (1,3-DPBF bleaching method). Then, bioassays were conducted using as biological models bacteria and yeast strains and a diode laser as a light source. Phytochemical analyses lead to the isolation of 5 isoquinoline alkaloids from oxoaporphine subclass, denominated GB1 to GB5. Photophysical and photochemical analysis showed that extracts, fraction and GB1 (isomoschatoline) presented absorption profile with bands at 600-700nm and were positive for singlet oxygen production. Photobiological assays indicate that these samples presented photodynamic antimicrobial activity against both gram-positive and gram-negative bacterial and some Candida ssp. yeast strains at sub-inhibitory concentrations. The susceptibility of gram-negative bacteria was significantly enhanced when CaCl2 or MgCl2 were employed. Greater energy doses and double sample's dosage also decreased microbial survival. It is suggested that GB1 photodynamic activity happens through both types I and II photochemical mechanisms, but with a predominance of the latter. Phytoderivatives of G. blepharophylla promoted antimicrobial effect, however more detailed study concerning chemical composition of the crude extracts and fractions as also photophysical and photochemical characteristics of GB1 are necessary to ensure their potential as photosensitizers at antimicrobial photodynamic inactivation.
Departamento de Biologia Vegetal, PPG BTPB and PPG BV, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil. Electronic address: nathilu@gmail.com.
Nathalia Luiza
NL
Andreazza
Departamento de Biologia Vegetal, PPG BTPB and PPG BV, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil.
Caroline
C
Caramano de Lourenço
Departamento de Biologia Vegetal, PPG BTPB and PPG BV, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil.
Álvaro José
ÁJ
Hernandez-Tasco
Departamento de Quıímica, Universidade Federal do Amazonas, Mini-Campus, Avenida General Rodrigo Otávio Jordão Ramos, 3000, Coroado, 69077-000 Manaus, AM, Brazil.
Maria Lúcia B
ML
Pinheiro
Departamento de Química, Universidade Federal do Paraná (UFPR), 81531-990 Curitiba, PR, Brazil.
Maria Élida
MÉ
Alves Stefanello
Departamento de Quıímica, Universidade Federal do Amazonas, Mini-Campus, Avenida General Rodrigo Otávio Jordão Ramos, 3000, Coroado, 69077-000 Manaus, AM, Brazil.
Emmanoel
E
Vilaça Costa
Departamento de Biologia Vegetal, PPG BTPB and PPG BV, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil. Electronic address: marcosjs@unicamp.br.
Marcos José
MJ
Salvador
D000470:Alkaloids / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001060:Aporphines / Q000494:pharmacology*; D031043:Guatteria / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence
D000470:Alkaloids; D000900:Anti-Bacterial Agents; D001060:Aporphines; D010936:Plant Extracts; C081279:aporphine
Antimicrobial photodynamic therapy; Antimicrobial resistance; Guatteria blepharophylla; Isoquinoline alkaloids; Oxoaporphine alkaloid isomoschatoline