계혈등으로부터 6종의 항균활성물질을 분리 정제하여 화학구조를 결정하였다. 계혈등 시료를 음건하여 80% aq. MeOH로 추출하고 감압 농축한 후 n-hexane, EtOAc, n-BuOH, 그리고 $H_2O$ 층으로 분획하였다. 각 분획을 이용하여 벼 도열별, 벼 잎집무늬마름병, 토마토 잿빛곰팡이병, 토마토 역병, 밀 붉은녹병, 보리 흰가루병 등 6가지 식물병에 대하여 식물병 방제효과를 검정한 결과, EtOAc 층이 가장 강한 활성을 보였으며, 벼 도열병, 토마토 잿빛 곰팡이병, 토마토 역병 및 보리 흰가루병에 대하여 80% 이상의 활성을 보였다. EtOAc층을 대상으로 silica gel chromatography 및 preparative TLC, HPLC 등을 이용하여 6종의 화합물을 분리, 정제하고 $^1H$-NMR, $^{13}C$-NMR, ESI-MS/MS, HMQC, $^1H-^1H$ COSY의 기기분석을 통해 ethanone, hydroxytyrosol, epicatechin, procyanidin B-2, dimethoxy daizein과 formononetin 으로 구조를 동정하였다. Epicatechin을 제외한 나머지 화합물들은 계혈등에서 처음으로 분리되었다. 분리한 물질들의 in vitro 및 in vivo 항균활성에 대한 연구를 진행하고 있다.
In the continued research on natural fungicides for control of plant diseases by using plant-derived products, we found that Spatholobus suberectus Dunn had a strong fungicidal activity against several plant pathogens. S. suberectus (1 kg) was extracted with 80% aqueous MeOH and then the concentrated extract was partitioned with n-hexane, EtOAc, n-BuOH and $H_2O$ successively. The four layers were tested their disease contron efficacies against 6 plant diseases such as rice blast (RCB), rice sheath blight (RSB), tomato grey mold (TGM), tomato late blight (TLB), wheat leaf rust (WLR), and barley powdery mildew (BPM). The EtOAc fraction was highly active showing over 80% control against RCB, TGM, TLB, and BPM. By using silica gel chromatography, preparative TLC and HPLC, six compounds that were expected to have antifungal activity were separated. Their chemical structures were identified as ethanone, hydroxytyrosol, epicatechin, procyanidin B2, dimethoxy daizein and formononetin by ESI-MS, $^1H$-NMR, $^{13}C$-NMR, and 2D-NMR spectroscopic analyses. The chemicals except epicatechin were first reported in S. suberectus. Study on in vitro and in vivo antifungal activities of the isolated compounds is in progress.
