Analysis of the obtained K and [[lambda].sub.0] values of the chitosan films of both molecular weights (Table 2) showed that the optical rotation of the films made of chitosan as a polysalt or a polybase was caused by the contributions of optically active chromophores with different locations of their absorption bands: [bar.[lambda]].sub.0] = 265 nm (CTS-87) and 200 nm (CTS-640) for acetic chitosan and [bar.[lambda]].sub.0] [approximately equal to] 150 nm (CTS-87) and 100 nm (CTS-640) for basic chitosan.
We note in passing that a change in the chiral structure of the polymer with inversion of the sign of specific optical rotation [a] was observed by us for samples of cellulose diacetate with various moisture contents as well .
These physical and chemical parameters determine the absolute value and sign of specific optical rotation of the preparations used, and an interrelation between the optical activity of chitosan and its biological action is now observed in two types of systems, namely, solutions and films.
The sugar was identified as methyl AY-D-galactopyranoside in case of 4 and AY-D- glucopyranoside for 5 based on the sign of optical rotation (D + 80.2; + 74.3) and Co-TLC profile (Rf 0.45 (EtOAc/MeOH/H2O; 5:2:0.5).
The stereochemistry could also be established due to the optical rotation value and found similar to that of 2.
GC-MS analysis identified the fatty acid, whereas, the optical rotation of methyl glucoside ([a]D = + 74.3) was comparable to the value [a]D = + 77.3 of D-glucose [17,18].
With our many in house quality assurance tools including mass spectrometry, gas chromatography, refractive index, specific, optical rotation
, flash points, head space analysis and a variety of wet analysis capabilities, we make every attempt to identify anomalies that would affect our customers' products.