Isolation and Structure Identification of Antifungal Substance from Aspergillus terreus

Aspergillus terreus로부터 항진균성 물질의 분리 및 구조분석

  • Kim, Keun-Ki (Gyeongsang National University, Department of Agricultural Chemistry) ;
  • Park, Ki-Hun (Gyeongsang National University, Department of Agricultural Chemistry) ;
  • Moon, Suk-Sik (Kongjoo National University, Department of Chemistry) ;
  • Kang, Kyu-Young (Gyeongsang National University, Department of Agricultural Chemistry)
  • Published : 1997.12.31

Abstract

In the course of search antagonistic fungi from soil in green house, four kind of fungi (AF1, AF2, AF3, AF4) were isolated, which have activities against Phytophthora capsici, Botrytis cinera, Rhizoctonia solani, Pythium ultimum and Fusarium oxysporum. The AF2 was identified according to the morphological description of Aspergillus terreus. This antagonistic fungus inhibiting various plant pathogens was effective to reduce disease incidence of cucumber seedlings caused by mixed inoculum of Rhizoctonia solani, Pythium ultimum and Fusarium oxysporum. Antifungal compound I was isolated and purified by fresh chromatography from A. terreus. The $^1H$ and $^{13}C$ assignment of compound I was achieved from two-dimensional $^1H-^1H\;COSY$, HMQC, HMBC with the add of homonuclear and heteronuclear double resonance experiment. The compound I was identified butyrolactone I (${\alpha}$-oxo-${\beta}$-(p-hydroxyphenyl)-${\gamma}$-(p-hydroxy-m-3,3-dimethyl-allylbenzyl)-${\gamma}$-methoxycarbonyl-${\gamma}$-butyrolactone, $C_{24}H_{24}O_7$, M.W.=424).

시설내 토양으로부터 식물병원균에 활성을 갖는 길항균을 탐색하는 과정에서 주요 식물 병원균인 Phytophthora capsici, Botrytis cinerea, Rhizoctonia solani, Pythium ultimum 및 Fusarium oxysporum에 활성을 갖는 4종류의 길항균(AF1, AE2, AE3, AF4)을 분리하였다. 이들 중 가장 높은 활성을 나타낸 AE2균을 동정한 결과, 생육한 균은 짙은 오렌지색과 황갈색을 띄었으며, 현미경의 morphology는 column형의 conidial head와 foot cell로 부터 곧게 뻗은 분생자와 2중층의 포자낭병을 형성했다. 그리고 MY20 agar 배지에서 투명한 둥근세포의 형성등이 Aspergillus terreus의 형태와 일치 하였다. Pot에서 병원균과 A. terreus를 동시에 처리하여 오이의 생육을 조사한 결과, 토양중량당 A. terreus의 균체를 1% 처리에 40%, 5% 처리에 57%, 10% 처리에는 75% 병발생율을 억제시켰다. 그리고 A. terreus의 배양여액으로부터 activity-guided fractionation을 실시하여 항진균성 물질인 화합물 I 을 얻었다. $^1H$, $^{13}C\;NMR$, DEPT, $^1H-^1H\;COSY$, HMQC, HMBC 및 질량스텍트럼을 분석한 결과 화합물 I 은 butyrolactone I (${\alpha}$-oxo-${\beta}$-(p-hydroxyphenyl)-${\gamma}$-(p-hydroxy-m-3,3-dimethyl-allylbenzyl)-${\gamma}$-methoxycarbonyl-${\gamma}$-butyrolactone, $C_{24}H_{24}O_7$, M.W. = 424)로 동정되었다.

Keywords