title: Inactivation of plant-pathogenic fungus Colletotrichum acutatum with natural plant-produced photosensitizers under solar radiation.
abstract: The increasing tolerance to currently used fungicides and the need for environmentally friendly antimicrobial approaches have stimulated the development of novel strategies to control plant-pathogenic fungi such as antimicrobial phototreatment (APT). We investigated the in vitro APT of the plant-pathogenic fungus Colletotrichum acutatum with furocoumarins and coumarins and solar radiation. The compounds used were: furocoumarins 8-methoxypsoralen (8-MOP) and 5,8-dimethoxypsoralen (isopimpinellin), coumarins 2H-chromen-2-one (coumarin), 7-hydroxycoumarin, 5,7-dimethoxycoumarin (citropten) and a mixture (3:1) of 7-methoxycoumarin and 5,7-dimethoxycoumarin. APT of conidia with crude extracts from 'Tahiti' acid lime, red and white grapefruit were also performed. Pure compounds were tested at 50μM concentration and mixtures and extracts at 12.5mgL(-1). The C. acutatum conidia suspension with or without the compounds was exposed to solar radiation for 1h. In addition, the effects of APT on the leaves of the plant host Citrus sinensis were determined. APT with 8-MOP was the most effective treatment, killing 100% of the conidia followed by the mixture of two coumarins and isopimpinellin that killed 99% and 64% of the conidia, respectively. APT with the extracts killed from 20% to 70% of the conidia, and the extract from 'Tahiti' lime was the most effective. No damage to sweet orange leaves was observed after APT with any of the compounds or extracts.
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
authors.forename: Letícia
authors.initials: L
authors.lastname: Fracarolli
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
authors.forename: Gabriela B
authors.initials: GB
authors.lastname: Rodrigues
authors.affiliation: Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Pereira
authors.affiliation: Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba, Brazil.
authors.forename: Nelson S
authors.initials: NS
authors.lastname: Massola Júnior
authors.affiliation: Fundecitrus, Fundo de Defesa da Citricultura, Araraquara, Brazil.
authors.forename: Geraldo José
authors.initials: GJ
authors.lastname: Silva-Junior
authors.affiliation: Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Bachmann
authors.affiliation: School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 3AF, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Wainwright
authors.affiliation: Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
authors.forename: Jairo Kenupp
authors.initials: JK
authors.lastname: Bastos
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. Electronic address: gbraga@fcfrp.usp.br.
authors.forename: Gilberto U L
authors.initials: GUL
authors.lastname: Braga
mesh_terms: D032084:Citrus sinensis / Q000737:chemistry / Q000382:microbiology*; D020231:Colletotrichum / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D004355:Drug Stability; D011564:Furocoumarins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects* / Q000528:radiation effects*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D011564:Furocoumarins; D017319:Photosensitizing Agents
keywords: Colletotrichum acutatum; Coumarins; Fungal photodynamic inactivation; Furocoumarins; Microbial photo inactivation; Photoantimicrobial