Potential ofD-erythro-C₁₄-Sphingosine as an Adjuvant for a Fungal Pesticide ofNomuraea rileyi

Abstract

D-erythro-C(14)-Sphingosin (C(14)-Sph) was isolated as the germination accelerating factor in Nomuraea rileyi in our previous study. This activity was expected to support fungal infection by reduction of the infection time between conidial adhesion and invasion into the insect. In this study, we estimated the effect of C(14)-Sph with regard to the infection time. Conidia activated by C(14)-Sph shortened the time to about half, indicating the potential of C(14)-Sph as an adjuvant for fungal pesticide of N. rileyi.

Characterization of a Germination-Accelerating Factor from the Silkworm (Bombyx moriLinnaeus) of Entomopathogenic FungusNomuraea rileyi(Farlow) Samson

“…A total of 12.4 mg of a substance (GAF) was isolated in the active fraction. 7) This isolated GAF was subjected to structural analyses. 10) It was found that GAF had the erythro (rel.…”

“…7) This leads to the hypothesis that an inactive precursor was present that produced active degradation products by the methanolysis digestion. The results of the present study reveal that GAF was probably C 14 -Sph.…”

“…The isolation process was the same as that described in the previous report. 7) Dried pupae (200 g) of crushed silkworm were extracted with methanol. The extract (21.2 g) in 1 MHCl methanol was heated and maintained at 100 C for 4 h. This methanolysis process increased the activity of the methanol extract.…”

“…In order to better understand the factor that accelerates the germination (GAF), our previous study has been extended to isolate the substance containing high-purity GAF from the pupae of silkworms, a host insect of N. rileyi. 7) This report describes the chemical structure of GAF and the structure-activity relationship.…”