Antimicrobial efficacy of extracts and constituents fractionated from Rheum tanguticum Maxim. ex Balf. rhizomes against phytopathogenic fungi and bacteria

作者:Duong Quang Pham; Duong Thi Ba; Nga Thu Dao; Choi Gyung Ja; Thuy Thu Vu; Kim Jin Cheol*; Thi Phuong Ly Giang; Hoang Dinh Vu*; Quang Le Dang*
来源:Industrial Crops and Products, 2017, 108: 442-450.
DOI:10.1016/j.indcrop.2017.06.067

摘要

The antimicrobial efficacies of extracts and constituents fractionated from Rheum tanguticwn rhizomes were evaluated by using in vitro and in vivo bioassay against seven phytopathogenic fungi and ten pathogenic bacteria, respectively. Dichloromethane and ethyl acetate soluble extracts derived from R. tanguticum rhizomes effectively controlled plant diseases caused by five fungi Magnaporthe oryzae, Blumeria graminis f. sp. hordei, Colletotrichum coccodes, Phytophthora infestans, and Puccinia recondita in in vivo whole plant bioassay. In addition, these extracts showed strong inhibitory activity against the bacterial growth of Acidovorax avenae subsp. cattlyae (Aac), Clavibacter michiganensis subsp. michiganensis, Xanthomonas arboricola pv. pruni (Xap), and Pseudomonas syringae pv. actinidiae (Psa), with MIC values ranging from 125 to 250 mu g/mL. The active extracts of R. tanguticum rhizomes were fractionated by using various and repeated chromatographic techniques to yield seven constituents that included three anthraquinones and four stilbenes. Notably, at concentrations ranging from 75 to 300 mu g/mL, physcion (DH03) and chrysophanol (DH04) were significantly effective in suppressing the development of barley powdery mildew (BPM) caused by B. graminis f. sp. hordei, with control values from 80 to 96.7%. Moreover, stilbenes rhapontigenin (D1102) and desoxyrhapontigenin (DH05) had a broad spectrum and potent activity against phytopathogenic bacteria; DH05 effectively inhibited the bacterial growth of Aac, Burkholderia glumae and Psa at MICs ranging from 38 to 150 mu g/mL. In this paper, we report their antibacterial activity for the first time. The botanical materials containing anthraquinones and stilbenes were active against both phytopathogenic fungi and bacteria. These results suggested that R. tanguticwn rhizomes could be used as a new source of antimicrobial substances for developing a botanical fungicide and bactericide to control plant diseases.

  • 出版日期2017-12-1