Geology Reference
In-Depth Information
Table 7.2
List of major products in the pyrolyzates of
Pandinus imperator
and
Limulus polyphemus
Peak
MS characteristics (m/z)
Compound name
Origin
1
92
, 91, 65
Toluene
Phenylalanine
2
81 ,
80
, 52
C
1
-Pyrroles
Proline, Hydroxyproline
3
104
, 78, 51
Styrene
Phenylalanine
4
95 ,
94
, 80
C
2
-Pyrrole
Hydroxyproline?
a
107 ,
79
, 51, 78
2-Pyridinecarboxaldehyde
Chitin
b
109 ,
67
, 107
Acetylpyrrole
Chitin
5
94
, 66
Phenol
Tyrosine
6
108
, 107, 77
C
1
-Phenol
Tyrosine
7
117
, 90, 116
Ethylcyanobenzene
Phenylalanine
c
123 ,
80
, 81, 52
Acetyldihydropyridine
Chitin
8
122 ,
107
C
2
-Phenol
Tyrosine
d
137 ,
109
, 95, 81, 68, 53
Acetylpyridone
Chitin
9
131 ,
91
, 65
Propylcyanobenzene
Phenylalanine
e
125 ,
83
, 54, 42, 53
3-Acetamidofuran
Chitin
10
117
, 90, 89
Indole
Tryptophan
f
139 ,
97
, 69, 42, 53
3-Acetamido-5-methylfuran
Chitin
g
153 ,
111
, 82, 42, 83
3-Acetamido-4-pyrone
Chitin
11
131 ,
130
, 77
C
1
-Indole
Tryptophan
h
185 ,
84
, 55, 83, 42
Oxazoline structure
Chitin
12
168 ,
70
, 97, 125, 165
2,5-Diketopiperazine derivatives
Proline-Alanine
13
154 ,
83
, 111, 70, 98
Pyrrolidinopiperazine derivatives
Proline-Glycine,
Proline-Lysine
14
70
, 154, 72, 55, 125
2,5-Diketopiperazine derivative
Proline-Valine,
Proline-Arginine
15
70
, 154, 125, 40, 54
2,5-Diketopiperazine derivative
Proline-Valine,
Proline-Arginine
16
194 ,
70
, 154, 54, 86
2,5-Diketopiperazine derivative
Proline-Proline
Notes
:
Letters = compounds characteristic of chitin and numbers refer to pyrolysis products of proteins.
m/z
values in
bold
indicate base peak and masses
underlined
indicate molecular ions (M
+
). Ions
after the base peak are in descending order of their relative abundances
C
1
refers to methyl, C
2
refers to dimethyl or ethyl etc.
Discussion
The fossilization of eurypterids was attributed to the decay resistant properties of
their cuticle (e.g., Clarke and Ruedemann
1912
). Indeed, the composition of the
cuticle of the most closely related living chelicerates as scorpions and horseshoe
crabs indicates that it is more decay resistant than other parts of the body.
Nonetheless, chitin is prone to degradation by chitinophosphatic bacteria
(Stankiewicz et al.
1998b
), as well as by oxidation and hydrolysis. The results of
this study confi rm that the cuticle of eurypterids is composed of a nonhydrolyzable
macromolecule with a long-chain aliphatic component similar to Type II kerogen,
and such a nonhydrolyzable aliphatic component is absent in the cuticle of their
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