Polymorphism of V-amylose cocrystallized with aliphatic diols

Chain-folded lamellar crystalline complexes of amylose with aliphatic diols were prepared and characterized by transmission electron microscopy as well X-ray diffraction. Four allomorphs identified, depending on the complexing diol crystallization conditions, that consisted orthorhombic lattices antiparallel 6- or 7-fold single helices. Straight-chain n-diols (ethane-1,2-diol, butane-1,4-diol, hexane-1,6-diol) yielded 6-fold helical regardless length linear chain, whereas a bulkier branched (2-methylpentane-2,4-diol) induced formation Butane-1,3-diol, contains straight carbon chain one end side hydroxyl group, both conformations conditions. When more than allomorph, an adequate control its concentration temperature allowed targeting specific form. Upon drying, all converted into compact pseudo-hexagonal structures. The dried form given complex generally retained same conformation hydrated one.