Dehydro-alpha-lapachone isolated from Catalpa ovata stems: activity against plant pathogenic fungi.
The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1).
Biological Function Research Team, Korea Research Institute of Chemical Technology, Yusong PO Box 107, Taejon 305-600, Korea.
Jun Young
JY
Cho
Hae Young
HY
Kim
Gyung Ja
GJ
Choi
Kyoung Soo
KS
Jang
He Kyoung
HK
Lim
Chi Hwan
CH
Lim
Kwang Yun
KY
Cho
Jin-Cheol
JC
Kim
D029402:Bignoniaceae / Q000737:chemistry*; D005658:Fungi; D005659:Fungicides, Industrial / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D009285:Naphthoquinones / Q000302:isolation & purification*; D010935:Plant Diseases; D018520:Plant Shoots / Q000737:chemistry; D010944:Plants / Q000382:microbiology*
D005659:Fungicides, Industrial; D009285:Naphthoquinones; C029244:xyloidone