Crinipellins A and I, Two Diterpenoids from the Basidiomycete Fungus Crinipellis rhizomaticola, as Potential Natural Fungicides.

Jae Han,Yu Lee,Mira Oh,Gyung Choi,Hun Kim,Jaehyuk Choi

doi:10.3390/molecules23092377

Abstract

In the course of screening for microbes with antifungal activity, we found that the culture filtrate of the IUM00035 isolate exhibited strong antifungal activity against Magnaporthe oryzae and Colletotrichum coccodes in planta. Based on the phylogenetic analysis with the ITS region, the IUM00035 isolate was identified as Crinipellis rhizomaticola. To identify antifungal compounds from the C. rhizomaticola IUM00035 isolate, the culture filtrate of the isolate was partitioned with ethyl acetate and n-butanol and, consequently, two active compounds were isolated from the ethyl acetate extract. The chemical structures of the isolated compounds were determined as crinipellin A (1) and a new crinipellin derivative, crinipellin I (2), by NMR spectral analyses and a comparison of their NMR and MS data with those reported in the literature. Crinipellin A (1) exhibited a wide range of antifungal activity in vitro against C. coccodes, M. oryzae, Botrytis cinerea, and Phytophthora infestans (MICs = 1, 8, 31, and 31 µg/mL, respectively). Furthermore, when plants were treated with crinipellin A (1) (500 µg/mL) prior to inoculation with fungal pathogens, crinipellin A (1) exhibited disease control values of 88%, 65%, and 60% compared with non-treatment control against tomato late blight, pepper anthracnose, and wheat leaf rust, respectively. In contrast to crinipellin A (1), crinipellin I (2) showed weak or no activity (MICs > 250 µg/mL). Taken together, our results show that the C. rhizomaticola IUM00035 isolate suppresses the development of plant fungal diseases, in part through the production of crinipellin A (1).

Highlights

Plant-pathogenic fungi cause severe plant diseases, resulting in a loss of crop yields and economic damage to the agricultural industry [1]
Synthetic fungicides have been recognized as a primary method to control plant diseases caused by fungal pathogens, the overuse of chemical pesticides has caused severe problems, such as toxicity for human health and environmental pollution
In the search for antifungal agents from mushrooms, we recently found that a culture filtrate

Summary

Introduction

Plant-pathogenic fungi cause severe plant diseases, resulting in a loss of crop yields and economic damage to the agricultural industry [1]. Synthetic fungicides have been recognized as a primary method to control plant diseases caused by fungal pathogens, the overuse of chemical pesticides has caused severe problems, such as toxicity for human health and environmental pollution. The development of safer and more effective alternatives is necessary to replace chemical pesticides [2]. Among the various natural resources, antagonistic microbes (or microbial metabolites) have been recognized as an attractive source for new antifungal agents [3]. Mushrooms have been used as a functional food or as active ingredients of folk medicine due to their various bioactive compounds [4]. Over 140,000 species of mushrooms have been

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Conclusion