Planta Med 2014; 80 - P1L61
DOI: 10.1055/s-0034-1394718

Isolation of the constituents and evaluation of allelopathic potential of Raphanus sativus L. (Brassicaceae)

LLR Fiorucci 1, GC Mantovanelli 1, DI Bernardi 1, AA Silva 2, RS de Oliveira Jr 1, EL Ishii- Iwamoto 1, MH Sarragiotto 1, DC Baldoqui 1
  • 1Universidade Estadual de Maringá, Av. Colombo, 5790, 87020 – 900, Maringá, PR, Brazil
  • 2Universidade Federal do Acre, BR 364, Km 04, 69915 – 900, Rio Branco, AC, Brazil

Raphanus sativus L., commonly known as “forage turnip”, is used as green fertilizer, and the straw has being used as ground cover and nutrient recycling [1]. Mulches of R. sativus L. used in no-till systems affect negatively the germination and establishment of weed seeds. In the present work, a bioguided identification of phytotoxic compounds of R. sativus was conducted [2 – 3]. Dried aerial parts of R. sativus (3.75 kg) were powered and exhaustively extracted with methanol at room temperature. Vacuum concentration yielded the crude methanol extract (293.6 g), which was suspended in MeOH:H2O (1:1) and partitioned into hexane, CH2Cl2, EtOAc and BuOH. The CH2Cl2 (1.71 g) and EtOAc (0.54 g) fractions were submitted to a successive chromatographic column (CC) over silica gel, Sephadex LH-20 and PVPP to afford four compounds. The isolated compounds were identified, by comparison of their spectroscopic data with those reported in the literature, as dehydrovomifoliol, kaempferol 3,7-di-O-α-L-rhamnopyranoside and quercetin 3,7-di-O-α-L-rhamnopyranoside, and ferulic acid. All compounds isolated in this work are being described for the first time in this species. The evaluation of allelopathic potential of R. sativus was carried forward to three undesirable species that most affecting soybean production: Euphorbia heterophylla, Bidens pilosa and Ipomoea triloba L.. The weed seeds were incubated in the presence of the partitioned fractions (250 – 1000 µg mL-1) in a growth chamber, at 25 or 30 °C, and at variable time intervals. The CH2Cl2 fraction was the most active among the partitioned fractions in all assayed weeds. The ethyl acetate fraction was less active and the other ones had no significant effects. The growth of primary roots was the most sensitive variable.

Keywords: Raphanus sativus L.; Allelopathic potential; Natural Products

References:

[1] Crusciol, C. A. C. et al. (2005) Pesq. Agrop. Bras. 40:161 – 168.

[2] Moraes, P.V. D. et al. (2010) Revis. FZVA 17: 51 – 67.

[3] Rizzardi, M. A. et al. (2006) Planta Daninha 24: 263 – 270.