Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

• Hidekazu Komatsu,
• Takashi Shirakawa,
• Takeo Uchiyama and
• Tsutomu Hoshino

Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27

• Administration, Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, 3-1-1 Kannondai, Tsukuba, Ibaraki 305-8519, Japan 10.3762/bjoc.15.27 Abstract Pseudomonas cichorii, which causes varnish spots on lettuce and seriously damages lettuce production during the

• alkaline hydrolysates, compounds A and B, were prepared. We discuss here the structure–activity relationships between the derivatives and their necrotic activities toward lettuce. Keywords: cichorinotoxin; lipodepsipeptide; necrotic lesion of lettuce; phytotoxin; Pseudomonas cichorii; Introduction

• Pseudomonas cichorii causes varnish spots on lettuce. Varnish spots, also called midrib rot or bacterial rot [1][2][3][4], are dark brown and can induce necrotic lesions [1][2][3][4][5][6][7]. P. cichorii, isolated by us, infects a wide range of host plants, including monocot and dicot species (e.g