Phytochemical analysis and fungicide potential of Pouteria ramiflora against Lasiodiplodia theobromae

Abstract

The use of plant extracts can be an alternative to reduce the use of pesticides, to control diseases and pests that affect agricultural production. The aim of this study was the chemical characterization of the extract and fractions of Pouteria ramiflora leaves and to determine its fungistatic potential on Lasiodiplodia theobromae. The ethanolic extract of dried and crushed leaves was obtained by maceration. Part of this extract was sequentially partitioned and the following fractions were obtained: hexane, dichloromethane, chloroform, ethyl acetate, n-butyl, and hydromethanol for subsequent bioassay, and qualitative and quantitative phytochemical analysis. Experimental development comprises of adding a L. theobromae mycelial disk (5 mm), obtained from pure colonies, in the middle of Petri dishes with PDA culture growth (potato-dextrose-agar) plus the aforementioned substances in different concentrations (800; 1,200; 1,600; 2,000, and 2,400 µg/mL), and a control treatment (PDA). The plates were incubated in B.O.D. (25±2°C), and the assessment was performed by measuring the diameter of the colonies until it reaches the edge of the board. The experimental design was completely randomized with five replications, and the treatments were constituted of a factorial of seven extracts/fractions and six concentrations. For the Mycelial Growth Rate Index (MGRI) obtained, the analysis of variance was performed, and when significant, the regression analysis was performed. All extract/fractions decreased MGRI of L. theobromae, as the concentrations were increased. The best MGRI reduction occurred in n-butanolic fraction, and the efficiency of this fraction may be related to the presence of flavonoids and anthraquinones. The extract and fractions of P. ramiflora, a tree from the Cerrado biome in Mato Grosso do Sul, was effective in the control of L. theobromae, which can be used as a control option in organic farming or in integrated management systems.

Phytochemistry and fungitoxic potential of extract and fractions of Pouteria ramiflora on Fusarium solani f. sp. phaseoli

“…These data confirm the predominance of these two classes of secondary metabolites. The spectra show the same chemical profile reported by Oliveira et al (2017), to the P. ramiflora leaves. The flavonoids exhibit in the visible ultraviolet two maximum peaks of absorption, one between 240-285 nm and another, 300-400 nm (ZUANAZZI; MONTANHA, 2003).…”

“…Only when it was used 2400 µg/mL, the IVCM reached 39.5%. Similar results were found by Oliveira et al (2017), where the IVCM of L. theobromae was reduced by up to 33% through the use of ethyl acetate and hydroethanolic fraction obtained from P. ramiflora leaves, demonstrating that these fractions have a small action in the fungi growth. However, these in vitro tests are essential for the selection of possible agents of alternative diseases control, as well as observed by Faria et al (2009), upon working with application of hydroethanolic extract of Momordica charantia L. before planting, in a preventive manner, observed a reduction of 74% of the disease severity caused by the fungus Sclerotium rolfsii.…”

“…The diversity of these compounds resulted, in the end, in significant reductions in the IVCM, reaching 47.8% (dichloromethane), 50.7% (chloroform) and 71.3% (Ext EtOH ), comparing to the control. Oliveira et al (2017) found similar results, also using P. ramiflora leaves and testing their action against L. theobromae, mentioning reduction in IVCM of 52.9% to dichloromethane and 59.6% for extract. However, the use of chloroform fraction resulted in a reduction in IVCM of 20.2%, much lower that the found by this research.…”

“…According to Silverstein et al (2014), the absorption between 430 to 490 nm refers to anthraquinones, what is observed for Ext EtOH and F Hex , F Acoet and F BuOH . In the qualitative analysis, this chemical group was detected by Oliveira et al (2017) only in Ext EtOH and F BuOH . On the other hand, the steroids, because they are heterocyclic, have characteristic absorption between 275 to 356 mm (SILVERSTEIN et al, 2014), situation observed in the spectrum of the ethanolic extract and F Hex , F CH2Cl2 and F Acoet (Figure 4).…”

“…Radlk., arboreal habit, has proved its biological activity. Among the studies already carried out, Oliveira et al (2017), researching the phytochemicals action present in the leaves, evidenced the presence of anthraquinones, phenolic compounds, coumarins, flavonoids and triterpenes, e. g. with the partition of the ethanolic extract and 599 Phytochemistry and fungitoxic… MATIAS, R. et al its fractions by decreasing the rate of Lasiodiplodia theobromae mycelial growth. Given the above, this study aimed to determine the secondary metabolites class from P. ramiflora leaves and its use through fractions and extract, in different concentrations, as a potential fungicide application on Fusarium solani f. sp.…”