Hydroxy compounds, with Starch

Tsuchiya et al utilized well-known iodo-starch reaction for sensing poly" hydroxy compounds. To realize that, amylose was modified with boronic acid moieties (Scheme 1.13). An aqueous solution containing the boronic acid-modified amylose and iodine (mixture of I2 andKI) is colored bluish purple due to encapsulation of iodine within the helical cavity of amylose. With increasing... 

Lipids also influence the properties of starch. Like free amino acids, monoglycerides or fatty acid esters of hydroxy acids, lipids form inclusion compounds with amylose (cf. 4.4.4.14.3). Like di- and triglycerides, they also reduce the swelling capacity and solubility by inhibiting water diffusion. Therefore, both degreasing as well as lipid addition are of importance as physical modification methods of starches. 

Starch and cellulose, two polymeric carbohydrates with many OH groups, were first discussed in Section 5.1. Starch is used for short-term energy storage, and cellulose is the major structural compound in plant and bacterial cell walls. The many hydroxy groups allow for substantial... 

A thixotropic starch was produced in reactions of POCl3-crosslinked starch with unsaturated aliphatic aldehydes.1361 Starch phosphates have been crosslinked by various aliphatic and aromatic aldehydes in the presence of urea, melamine, and similar compounds. Among several aldehydes tested[formaldehyde, propanal (propionaldehyde), glyoxal, glutaraldehyde, 2-hydroxyadipaldehyde (2-hydroxy -1,6-hexanedial), and some aromatic aldehydes], only those products that had reacted with glyoxal were insoluble in water.1322 Significant increases in viscosity occurred after starch phosphates having a low DS were treated with urea.1590... 

Preparation by fluorination of p-hydroxyacetophenone (2 mmol) with l-fluoro-4-hydroxy-l,4-diazoniabicyclo-[2.2.2] octane bis(tetrafluoroborate)(Accufluor NFTh) (2.1 mmol of active compound) in refluxing methanol for 0.5-4 h until potassium iodide starch paper showed the consumption of the fluorinating reagent. Thrai, hydrolysis of the dimethyUcetal formed with 10% hydrochloric acid solution in acetonitrile (75-85%) [4683]. 

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