150 JOURNAL OF COSMETIC SCIENCE
CHEMICAL CHARACTERIZATION OF THE POLYPHENOL TREATED HAIR FIBERS
We next assayed the amino acid residues of the water-soluble keratin and the bleached hair
which were treated with chicoric acid in the presence of the copper salt (4 ppm). Table I
lists the amino acid compositions before and after the treatment. The lysine, histidine and
cysteine residues were substantially decreased in both the keratin protein and the bleached
hair after the treatment see the three residues from the bottom of Table I. Also, the
UV-spectrometric quantification clearly indicated that the cysteine content of the protein
was decreased to about one-fifth level treatment with the polyphenol and the copper salt, as
shown in Figure 5. These results of the SDS-PAGE and the amino acid analysis suggest that
the lysine, histidine, and cysteine residues were chiefly modified with the polyphenols in
the presence of copper (II) ions to polymerize the keratin proteins. Similarly, Yamauchi and
coworkers studied an artificial sclerotization of gelatin to conclude that these amino acid
residues reacted with hydroquinone, catechol, and others to rapidly harden the structural
protein in the presence of a catalytic concentration by copper (II) ions.12
On the other hand, Figure 6 shows cross-sectional photographs of untreated hair, the
bleached hair, and the chicoric acid treated bleached-hair, each of which was stained with
the fluorescent dye (FITC-I) in the same conditions. Note that the dye generally reacts
with the lysine, histidine, and cysteine residues of a protein.22 The untreated hair gave
the weak fluorescence only on the thin surface of the fiber as seen in Figure 6A. The
bleached hair was stained more intensity with FITC-I, especially in the cuticle region and
the medulla regions,23 which were abundant with lysine and cysteine residues (Figure 6B).24
Figure 4. SDS-PAGE patterns of the keratin protein (IFP-HMW) which was treated with the polyphenol
(hydroquinone and chicoric acid) in the presence of copper (II) chlorophyllin (4 ppm). The concentration (mM)
of the polyphenols is indicated on the upper side of the lanes. CBB was used as a staining agent.
151 Repairing Bleach-Damaged Hair
Table I
Effects of the Treatment with Chicoric Acid and Copper (II) Chlorophyllin on the Amino Acid Compositions
of the Keratin Protein and the Bleached Haira
Keratin
Protein
Chicoric acid treated
keratin protein (The
rate of change by the
treatment)
Bleached
hair
Chicoric acid treated
bleached hair (The
rate of change by the
treatment)
Asp(Asn) 63.1 63.1 (1.0) 56.4 56.4 (1.0)
Glu(Gln) 113.6 113.9 (1.0) 106.2 111.1 (1.0)
Ser 83.8 82.0 (1.0) 91.9 94.5 (1.0)
Gly 62.8 58.6 (0.9) 50.1 49.5 (1.0)
Thr 53.7 54.2 (1.0) 62.0 66.1 (1.1)
Arg 64.2 62.1 (1.0) 57.7 58.6 (1.0)
Ala 48.6 48.3 (1.0) 38.6 40.3 (1.0)
Tyr 20.0 18.2 (0.9) 17.7 18.0 (1.0)
Val 43.4 46.1 (1.1) 39.6 40.6 (1.0)
Met 3.3 3.0 (0.9) 4.3 4.3 (1.0)
Phe 22.7 22.8 (1.0) 15.4 14.0 (0.9)
Ile 29.6 30.4 (1.0) 21.8 22.9 (1.1)
Leu 73.1 73.7 (1.0) 49.0 46.8 (1.0)
Pro 68.7 62.7 (0.9) 69.3 61.2 (0.9)
His 4.0 2.0 (0.5) 7.8 5.1 (0.7)
Lys 20.6 11.9 (0.6) 23.3 13.7 (0.6)
Cys b 224.6 152.2 (0.7) 288.9 180.7 (0.6)
Total 1000 1000 1000 1000
(a) The keratin protein was treated with chicoric acid (3.6 mM) in the presence of the copper salt (4 ppm).
The bleached hair fibers were treated with chicoric acid (8.4 mM) in the presence of the copper salt
(4 ppm). Total amino acid content was assumed to 1000 residues. Tryptophan was not observed.
(b) A combined total of the cysteine and half-cysteine contents. The sum was not significantly altered
between different runs of the treatment. By contrast, the individual contents for the amino acid residues
were substantially varied, presumably owing to a complex redox action of the polyphenol-quinone
system in the present treatment.20,21
Figure 5. The UV-spectroscopic quantitative assay of the cysteine residue of the keratin protein which
treated under various conditions. (A) No treatment (B) only chicoric acid (C) only copper (II) chlorophyllin
(D) chicoric acid and the copper salt. See the experimental section for the spectroscopic quantification of the
thiol group.
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