Phytochemical prospecting and biological activities of the floral extract from [Impatiens walleriana (Hook.)] (Balsaminaceae)

Impatiens walleriana is a plant species that presents diversity and variety of colors among flowers. This plant species has wide distribution and is easily cultivable throughout the world including natural gardens, greenhouses and parks. This study aims at evaluating the floral extracts of I. walleriana in terms of their qualitative phytochemical constitution and antifungal activities on Sclerotinia sclerotiorum, Colletotrichum gloeosporioides and Colletotrichum acutatum, as well as on the reduction of DPPH free radical and on the inhibition of acetylcholinesterase (AChE). Flowers were collected from two cultivars Pink and White of I. walleriana and the extract produced by maceration. The phytochemical qualitative assay was carried out using different reagents for determination by precipitation or colorimetric alteration. The antifungal test was carried out in Petri dishes with different concentrations of floral extract on S. sclerotiorum, C. gloeosporioides and C. acutatum. The DPPH reduction assay was performed by percentage and as standard antioxidant ascorbic acid. The acetylcholinesterase inhibition test was performed in percentage using Electrophorus electricus. Positive results were observed for phenolics, anthocyanins, organic acids, alkaloids, catechins, tannins, carboxylic acids, hemolytic saponins and sesquiterpene lactones. Fungal inhibition effect was better observed for cv. Pink with 10-26%, 6% and between 9-11% on S. sclerotiorum, C. gloeosporioides and C. acutatum, respectively. The DPPH reduction activity showed satisfactory results for cv. Pink 49% followed by cv. White 41%. And for inhibition of AChE cv. Pink with 30% and cv. White with 27%. The floral extracts of Impatiens walleriana show good results for the biological activities tested, especially for cv. Pink.