Elsinan

Structure and Enzymatic Degradation of Elsinan, a New a-D-Glucan Produced by Elsinoe leucospila... 

In this paper, we describe the production, detailed structure, enzymatic degradation and isolation of novel oligosaccharides, and also derivatization, such as 3,6-anhydro-elsinan. Some of rheological properties and potential utilization of this glucan will also be discussed. 

Figure 1. Time course of production of elsinan. Five liter medium containing sucrose was fermented with airation, 5-6.5 L/min and agitation, 300 rpm, at 24°C elsinan (O) dry cell (—A--) sucrose (— X —) pH reducing...

Figure 2. Effects of carbon sources on the production of elsinan...

YIELDS AND METHYLATION ANALYSES OF ELSINAN PRODUCED FROM VARIOUS CARBON SOURCES... 

Elsinan was produced by shaking culture in a medium containing 5% of the carbon source and 0.5% of corn steep-liquor. 

For examination of detailed structural features, elsinan was subjected to partial, acid hydrolysis with 0.5 M sulfuric acid for 4 h at 85°. The degradation products were fractionated by a Charcoal column, followed by preparative, paper chromatography. Table II shows the results of the fractionation. 

YIELDS OF OLIGOSACCHARIDE FRACTIONS FROM PARTIAL ACID HYDROLYSIS OF ELSINAN... 

Figure 5. Repeating unit of elsinan I, maltose II, nigerose III, maltotriose IV, 3-O-a-D-glucosylmaltose V, 4-O-a-o-glycosylnigerose VI, maltotetraose (6j.

In relation to chemical taxonomy, other plant pathogenic fungi belonging to the Elsinoe species, such as E. fawetti, responsible for citrus scab, have also been found to produce extracellular a-D-glucans similar to the elsinan of E. leucospila. 

Since elsinan has a unique structural feature, its digesta-bility and also methanism of the enzymatic degradation have attracted our attention. In the searches of enzymes capable of degrading this glucan, we became aware of susceptibility of elsinan to particular type of a-amylase, such as salivary and pancreas amylase. This prompted us to examine various amylolytic enzymes, and isolation of the degradation products. 

Enzyme Hydrolysis(%) Velocity elsinan soluble (soluble starch starch =100) ... 

The enzyme digest from elsinan was shown by paper chromatography to contain glucose, disaccharide, trisaccharide and tetrasaccharide. Figure 7 shows the profile of h.p.l.c. of these oligosaccharides. 

REACTION PRODUCT OF ELSINAN WITH SEVERAL CC-AMYLASE... 

Figure 6. Time course of enzymatic hydrolysis of elsinan with human salivary cL-amylase ( ) enzyme was supplemented (12)...

Figure 7. High performance liquid chromatography of reaction product of elsinan with human salivary a-amylase.

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