Abstract:In this paper, the biosynthesis process of phenolic compounds in plants is summarized, which includes the shikimate, pentose phosphate and phenylpropanoid pathways. Plant phenolic compounds can act as antioxidants, structural polymers (lignin), attractants (flavonoids and carotenoids), UV screens (flavonoids), signal compounds (salicylic acid and flavonoids) and defense response chemicals (tannins and phytoalexins). From a human physiological standpoint, phenolic compounds are vital in defense responses, such as anti-aging, anti-inflammatory, antioxidant and anti-proliferative activities. Therefore, it is beneficial to eat such plant foods that have a high antioxidant compound content, which will cut down the incidence of certain chronic diseases, for instance diabetes, cancers and cardiovascular diseases, through the management of oxidative stress. Furthermore, berries and other fruits with low-amylase and high-glucosidase inhibitory activities could be regarded as candidate food items in the control of the early stages of hyperglycemia associated with type 2 diabetes.

The crystal structures of the A-, B-and C-polymorphs of amylose have been determined through a combination of fiber x-ray diffraction analysis and computer-based structure refinement. The three structures correspond to the naturally occurring A-, B-and Cstarches. A-and B-structures differ in the crystalline packing of the helices and the water content. The C-structure is a mixture of Aand B-unit cells and, therefore, intermediate between the A-and B-forms in packing density. Die Kristallstrukturen der polymorphen FormenA, B und C von Amylose und Starke. Die Kristallstrukturen der polymorphen Formen A, B und C von Amylose wurden mit Hilfe einer Kombination der Faser-Rontgenbeugungsanalyse und der Struktur-Raffinierung auf Computerbasis untersucht. Die drei Strukturen entsprechen dennaturlich vorkommenden A-, Bund C-Starken. Die A-und B-Strukturen unterscheiden sich hinsichtlich der kristallinen Packungsdichte der Helices und des Wassergehaltes. Die C-Struktur ist eine Mischung aus A-und B-Elementarzellen und steht somit hinsichtlich ihrer Packungsdichte zwischen der A-und B-Form.

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