Higher plant celluloses allomorphs

One of the discoveries growing out of the early diffractometric studies of cellulose was that it can occur in a number of allomorphic forms in the solid state, each producing distinctive X-ray diffractometric patterns. In addition to the cellulose II form, which has been discussed extensively, two other forms have been recognized these are cellulose III and cellulose IV. It is of interest to consider them briefly because they reflect the capacity of cellulose to aggregate in a wide variety of secondary and tertiary structures and because some of the higher plant celluloses produce diffraction patterns that are not unlike those of cellulose IV. Furthermore, they reflect the tendency for some of the celluloses to retain some memory of their earlier states of aggregation in a manner not yet understood. 

The ratio of these two allomorphs depends on the different sources of cellulose. Cellulose la is usually known to be predominant in bacteria and algae, while ip allomorph is prevalent in higher plants (Brannvall, 2007 Siqueira et al., 2010). However, Atalla and VanderHart have demonstrated some pecuharities in the NMR spectra of higher plants cellulose, which seemed to suggest that higher plants con-... 

There are several polymorphs of crystalline cellulose-I, II, III, and IV. Each has been extensively studied [4]. Crystalline cellulose that is naturally produced by a variety of organisms, it is sometimes referred to as "natural cellulose. Cellulose-I has two polymorphs, a triclinic structure [ ) and a monoclinic structure [I ], which coexist in various proportions depending on the cellulose source. The Iq structure is the dominate polymorph for most algae and bacteria, whereas is the dominant polymorph for higher plant cell wall cellulose and in tunicates [5-7]. Allomorph ratios are species specific, and this gives rise to natural structural variations in cellulose crystals. However, the mechanisms contributing to crystal formation remain unknown [8]. 

---