43
Figure 1: Chemical structure of one unit in a chondroitin sulfate chain. Chondroitin-4-sulfate: R1
44
= H; R2 = SO3H; R3 = H. Chondroitin-6-sulfate: R1 = SO3H; R2, R3 = H. Chondroitin-6-sulfate: R1 =
45
SO3H; R2, R3 = H. Chondroitin sulfate has also a linkage region to consisting of GlcAβ-1-3Galβ-1-
46
3Galβ-1-4Xylβ-1-O-Ser, and a capping trisulfated monosaccharide. Commercial chondroitin
47
sulfate has a varying content of non-sulfated disaccharides and it may contain some degree of
48
decarboxylation depending on the isolation and purification treatment. Sulfation position
49
depends on the species from which it is derived, age of the animals and anatomic location of the
50
cartilage.
51
52
Dietary Ingredients
53
A vitamin; a mineral; an herb or other botanical; an amino acid; a dietary substance for use
54
by man to supplement the diet by increasing total dietary intake; or a concentrate,
55
metabolite, constituent, extract, or combination of any of the above dietary ingredients
56
57
Dietary supplements
58
A product intended for ingestion that contains a "dietary ingredient" intended to add
59
further nutritional value to (supplement) the diet. Dietary supplements may be found in
60
many forms such as tablets, capsules, softgels, gelcaps, liquids, or powders.
61
62
Limit of Quantitation (LOQ):
63
The minimum analyte concentration for which quantitative results may be obtained with 95%
64
confidence.
65
66
Repeatability:
67
Variation arising when all efforts are made to keep conditions constant by using the same
68
instrument and operator, and repeating during a short time period. Expressed as the
69
repeatability standard deviation (SD
r
), or % repeatability relative standard deviation (%RSD
r
).
70
71
Reproducibility:
72
The standard deviation or relative standard deviation calculated from among-laboratory data.
73
Expressed as the reproducibility relative standard deviation (SD
R
) or %reproducibility relative
74
standard deviation (%RSD
R
).
75
76
Recovery:
77
The fraction or percentage of the analyte that is recovered when the test sample is analyzed
78
using the entire method.
79
80
FDA.
2
