Wednesday, 23 September 2015

Environmental trends in the variation of biologically active phenolic compounds in Labrador tea, Rhododendron groenlandicum, from northern Quebec, Canada

Michel Rapinski,a Rui Liu,b Ammar Saleem,b John Thor Arnason,b Alain Cuerriera
aInstitut de recherche en biologie végétale, Jardin botanique de Montréal, Université de Montréal, 4101 Sherbrooke Est, Montréal, QC H1X 2B2, Canada.
bCentre for Research in Biotechnology and Biopharmaceuticals, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
Corresponding author: Alain Cuerrier (e-mail: ).
Published on the web 25 August 2014.
Received December 5, 2013. Accepted August 7, 2014.

Botany, 2014, 92(11): 783-794, 10.1139/cjb-2013-0308


The impact of several environmental factors on the production of phenolic compounds in a North American medicinal plant, Labrador tea (Rhododendron groenlandicum (Oeder) Kron & Judd), was studied. Leaves were harvested in 2006 and 2010 over a latitudinal gradient in northern Quebec, and known phenolic markers were quantified by HPLC-DAD. The concentration of selected compounds varied geographically where they were higher between the 51st and 53rd parallel of northern Quebec and lower in the peripheral northern and southern region. Major variations were observed in the following marker compounds: (+)-catechin, (–)-epicatechin, quercetin-3-galactoside, and an undetermined quercetin-glycoside. The variation in phenolic compounds was best explained by short-term changes in annual temperature range and long-term estimates of insolation parameters such as solar radiation and photoperiod in the month of June.