Sophorose structure

Draw the structures of a-sophorose, a-melibiose, and lactulose. Sophorose is two glucoses linked /3 (1-2). Melibiose is a galactose linked to a glucose by an a (1-6) bond. Lactulose is galactose linked /3 (1-4) to fructose. 

The stimulation of the synthesis of the cellulase system of T. reesei QM 9414 by sophorose was established as shown by the results of experiments summarized in Table IV. Other than sophorose, of the glycosides and oligosaccharides tested, only lactose caused even a limited production of the enzymes of the cellulase system. Lactose is not as closely related structurally to sophorose as is, for example, the disaccharide laminaribiose it is more closely related structurally to cellobiose, which, despite being the major product of cellulose breakdown, does not promote enzyme production under the conditions of this experiment. It was noted that both intra- and extracellular constitutive enzyme levels produced by cells growing on glucose (or by resting cells without inducer, Table IV) are less than 0.5% of the fully induced levels and thus are negligible. 

The CBH I (D) is identical in composition and activity to the CBH I (D) previously described (2) from T. reesei QM 9123. The close correspondence of their amino acid contents (Table VI), the nearly identical content of neutral carbohydrate 6.8% by weight for the CBH I (D) produced in the presence of sophorose and 6.7% for T. reesei QM 9123 CBH I (D) grown on cellulose (2), and identical electrophoretic properties clearly argue for a common molecular structure for these CBH s I (D). The CBH II is clearly different from all other CBH s in electrophoretic mobility (Figure 12) and amino acid composition (41), but is devoid of endoglucanase activity and produces predominantly cellobiose (>90% by weight of soluble products) from cellulose. It has a sedimentation coefficient of 3.71 in comparison to CBH I (D), for which a value of 3.66 was obtained. 

FlG. 9.—Structure of Sophorose (2-0-/3-D-Glucopyranosyl-D-glucose). (The site of interaction with con A is outlined. From Ref. 240. Printed by permission of Ann. N.Y. Acad. Sci.)... 

Figure 5.2 Selected sugars and aromatic or aliphatic acids that commonly occur in anthocyanin structures. Sophorose = 2-O-b-D-glucopyranosyl-D-glucose rutinose = 6-O-L-rhamnosyl-D-glucose sambubiose = P-D-xylosyl-(l 2)-P-D-glucose.

Figure 12.18 Examples of lipid structures and oil soluble compounds A) tria-cylglycerol B) ceramide C) phospholipid (with enzymatic modification sites) D) sophorose lipid E) carotene F) sitosterol.

Sophorose, found in certain types of beans, has the following Haworth structure ... 

Structure of the lactonic sophorose lipid of Torulopsis bombicola... 

Asmer, H. J., Lang, S., Wagner, F. and Wray, V. (1988) Microbial-production, structure elucidation and bioconversion of sophorose lipids. J. Am. Oil Chem. Soc., 65, 1460-1466. Esders, T. W. and Light, R. J. (1972) Glucosyl- and acetyltransferases involved in the biosynthesis of glycoUpids from Candida bogoriensis. J. Biol. Chem., 247, 1375-1386. 

---