Spectrophotometric Determinations of Chloroplastidic Pigments in Physalis angulata L. Leaves Using Different Methodologies

Tamara Torres Tanan,David Santana Guimarães,Marilza Neves Do Nascimento,Romeu Da Silva Leite

doi:10.5539/jas.v9n11p117

Abstract

The aim of this study was to compare different protocols for extraction and quantification of photosynthetic pigments, considering different solvents, extraction time and temperature, to determine the best methodology for Physalis angulata L. leaves. The efficiency of immersion of leaf discs in 95% ethanol, 80% acetone and dimethyl sulfoxide (DMSO) was evaluated for 24, 48 and 72 hours. The effect of temperature on extraction with DMSO was also evaluated, with the samples incubated at room temperature and in a water bath at 65 °C. These protocols were compared with the classical methods of plant tissue maceration in 80% acetone followed by filtration, which proved to be the most efficient for Physalis angulata plants and indicated for use in the laboratory. The use of high temperatures (65 °C) is not necessary for the chlorophyll extraction process with DMSO, the room temperature is most efficient in the extraction of carotenoids. Considering the total chlorophyll content, the leaf discs immersion technique in a solvent is acceptable, with 95% ethanol and 24 hours incubation and the most economically viable alternative.

Highlights

Chlorophylls are the most abundant natural pigments found in plants
In relation to the time required for chlorophyll extraction, 95% ethanol and dimethyl sulfoxide (DMSO) were faster, being efficient with 24 hours of incubation
The data were set for the same model, corresponding to a rectangular hyperbole; the adjustments were highly efficient, as demonstrated by R2 values above 0.95 obtained for chlorophylls, except carotenoids

Summary

Introduction

Chlorophylls are the most abundant natural pigments found in plants. The other pigments, known as accessory pigments such as chlorophyll β and carotenoids, aid in the light absorption and in the transfer of radiant energy to the reaction centers (Taiz & Zeiger, 2004). The photosynthetic pigments found in chloroplasts and are responsible for the conversion of light radiation into energy, such as ATP and NADPH, because of that, closely related to the photosynthetic efficiency of plants and primary productivity (Taiz & Zeiger, 2004). How nitrogen is a constituent of the chlorophyll molecule, the content of this pigment in the leaf used to predict the nutritional level of nitrogen in plants (Silveira, Braz, & Didonet, 2003)

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