title: Ultraviolet-B radiation effects on phenolic profile and flavonoid content of Kalanchoe pinnata.
abstract: Ultraviolet-B radiation is an important abiotic factor that can stimulate the production of secondary metabolites, including polyphenolic compounds. Kalanchoe pinnata (Crassulaceae) is a medicinal plant popularly used in Brazil for treating wounds and inflammation. This species is rich in phenolic compounds, which could account for some of its biological activities, including antileishmanial, antihypertensive and antibacterial properties. We investigated the effects of supplemental UV-B radiation on the phenolic profile, antioxidant activity and total flavonoid content of leaves of K. pinnata. Plants were grown under white light (W - control) and supplemental UV-B radiation (W+UVB). Supplemental UV-B radiation enhanced the total flavonoid content of the leaf extracts, without affecting the antioxidant activity or yield of extracts. Analysis by TLC and HPLC of W and W+UVB leaf extracts revealed quantitative and qualitative differences in their phenolic profiles. W+UVB extracts contained a higher diversity of phenolic compounds and a larger amount of quercitrin, an important bioactive flavonoid of this species. This is the first report of the use of ImageJ® program to analyze a TLC visualized by spraying with NP-PEG reagent. UV-B radiation is proposed as a supplemental light source in K. pinnata cultivation in order to improve its flavonoid composition.
authors.affiliation: Plant Anatomy Laboratory, Botanical Department, Biology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: luanabeatriznascimento@ig.com.br.
authors.forename: Luana Beatriz Dos Santos
authors.initials: LBDS
authors.lastname: Nascimento
authors.affiliation: Federal Institute of Education, Science and Technology, Campos dos Goytacazes, Brazil. Electronic address: mlealcosta@gmail.com.
authors.forename: Marcos Vinicius
authors.initials: MV
authors.lastname: Leal-Costa
authors.affiliation: Plant Anatomy Laboratory, Botanical Department, Biology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: elo.aragao@yahoo.com.br.
authors.forename: Eloá Aragão
authors.initials: EA
authors.lastname: Menezes
authors.affiliation: Plant Anatomy Laboratory, Botanical Department, Biology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: virginialua7@gmail.com.
authors.forename: Virgínia Rodrigues
authors.initials: VR
authors.lastname: Lopes
authors.affiliation: Bioactive Products Laboratory, Federal University of Rio de Janeiro, Macaé, Brazil. Electronic address: mfmuzitano@gmail.com.
authors.forename: Michelle Frazão
authors.initials: MF
authors.lastname: Muzitano
authors.affiliation: Chemistry of Natural Bioactive Products Laboratory, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: sscostabh@gmail.com.
authors.forename: Sônia Soares
authors.initials: SS
authors.lastname: Costa
authors.affiliation: Plant Anatomy Laboratory, Botanical Department, Biology Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: elianast@gmail.com.
authors.forename: Eliana Schwartz
authors.initials: ES
authors.lastname: Tavares
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005419:Flavonoids / Q000032:analysis / Q000737:chemistry*; D031962:Kalanchoe / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects*; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts