Table III.

Predicted and experimentally observed products of endo-β-mannanase digestion of labeled M5G, M6G, M7G and M8G formed using digitonin-solubilized fenugreek GMGT.

Deduced Structures of Positional Isomers with Predicted Labeled Endo-β-Mannanase ProductsRelative Proportions of Labeled M2G and M3G Released on Endo-β-Mannanase Digestion
PredictedExperimental3-b
M2G M3G M2G M3G
M5G20 ± 380 ± 324 ± 276 ± 2
 MGMMM → M2G
 MMGMM → M3G
M6G26 ± 375 ± 425 ± 175 ± 1
 MGMMMM → M2G
 MMGMMM → M3G
 MMMGMM → M2G
M7G61 ± 441 ± 257 ± 243 ± 2
 MGMMMMM → M2G
 MMGMMMM → M3G
 MMMGMMM → M2G
 MMMMGMM → M2G
M8G73 ± 428 ± 468 ± 132 ± 1
 MGMMMMMM → M2G
 MMGMMMMM → M3G
 MMMGMMMM → M2G
 MMMMGMMM → M2G
 MMMMMGMM → M2G +M3G3-b

Experimental data were obtained by digesting M5G to M8G completely with A. niger endo-β-mannanase, separating the digests by TLC and determining the relative proportions of the product oligosaccharides M2G and M3G by quantitative digital autoradiography. Predictions were made using the known specificity of the endo-β-mannanase (McCleary and Matheson, 1983; summarized in text) and the digitonin data from Table II.

    • F3-a Mean (± se) of at least two independent experiments.

    • F3-b Assumed 50% of each.