Phytochemistry and Allelophatic Potential of Torelliodora Eucalyptus Leaves on Germination and Initial Growth of Mutambo

Abstract

Considering the possibility of a intercropping between exotic and native wood species for Legal Reserve areas restoration, information is needed about the possible interactions (positive or negative) between the involved species. The aim of this study was to determine the allelochemicals classes of aqueous extracts from dried and fresh leaves of torelliodora eucalyptus, as well as to evaluate the allelopathic potential of these extracts in the germination and initial growth of Guazuma ulmifola, a native species from Cerrado. To obtain the aqueous extracts at the concentrations of 25 mg mL-1, 50 mg mL-1, 100 mg mL-1 and 200 mg mL-1, the fresh and dried leaves of the eucalyptus were separately subjected to turbolize, followed by an ultrasound bath for two hours and static maceration, in darkness, for 48 hours in a refrigerator. The extracts were subjected to classical phytochemical analysis and determination of pH, electrical conductivity, soluble solids and allelopathic tests. For the germination and growth biological tests, a completely randomized experimental design with four replications per treatment was performed. The phytochemical analysis indicated that the phenolic compounds and derivatives are the major constituents of the aqueous extract of fresh and dried leaves of the tolleriodora eucalyptus, with predominance of the flavonoid contents on the dried leaves. Dried and fresh leaves extracts of torelliodora eucalyptus influenced G. ulmifolia germination, but this effect was dependent on their concentration. Initial seedling growth of G. ulmifolia was negatively influenced only by the dried leaves extract of the exotic species.

Ursolic Acid and Its Derivatives as Bioactive Agents

“…These effects can also be beneficial for host plants, inhibiting the development of pathogenic fungus organisms as a result of their antibacterial, antifungal and growth-inhibiting activities [115]. Phenolic compounds and their derivatives, particularly simple phenols such as phenolic acids, affect the permeability of the membrane, inhibiting the growth of the aerial part and the elongation of the roots [89]. Specifically, the IC 50 values of UA range between 75 and 700 µM for drastic growth of Lactuca sativa (lettuce) [89,116].…”

“…Phenolic compounds and their derivatives, particularly simple phenols such as phenolic acids, affect the permeability of the membrane, inhibiting the growth of the aerial part and the elongation of the roots [89]. Specifically, the IC 50 values of UA range between 75 and 700 µM for drastic growth of Lactuca sativa (lettuce) [89,116]. Tuyen et al [74] explored an interesting isolation and elucidation of a naturally occurring UA derivative called 2_,3_,7_,23-tetrahydroxyurs-12-ene-28-oic acid (118) from Castanea crenata (Japanese chestnut).…”