Structures of branched and linear molecules of rice amylose

✍ Scribed by Yasuhito Takeda; Shinji Tomooka; Susumu Hizukuri

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 397 KB
• Volume: 246
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(93)84038-8

✦ Synopsis

The structures of branched and linear molecules of the isolated amylose (number-average dp 850) from rice were examined by the tritium labeling method and gel-permeation chromatography. The branched and linear molecules showed similar, symmetrical distributions on a molar basis with a dp of 710 and 540 at the peak, respectively, and different distributions on a weight basis with a dp of 4440 and 710 at the peak, respectively. The branched and linear molecules had a d& of 1180 and 740, respectively, and the ratios of the branched to the linear molecule were 0.22:0.78 by mole and 0.32:0.68 by weight. The chromatogram of the reduced tritiated isoamylolyzate, from the reduced amylose, revealed that the branched molecule had side chains with various sixes (dp * 10-4000). The side chains had a peak dp of 21. The long side chain accompanied another chain(s). Thus, the branched molecule is a structural intermediate between true linear amylose and amylopectin.