Thesis-Final 03 June 2011 pdf - Jacobs University

Results and discussion Chapter 3
13 C-NMR spectrum signals were consistent with the 1 H-NMR spectrum. The 13 C-
NMR spectrum showed that some of the signals were overlapped due to the same kind
of chemical shifts. The first peak at 21.21 ppm with three carbon intensity identified
as C-38, C-39 and C-40. Then this signal followed by quinide carbons. The peak at
33.97 and 34.51 ppm identified as C-2 and C-6 due to cross peaks at 1 H 1 H-COSY and
1 H 13 C-HMQC spectrums. Another four signals of quinide carbons found at 66.15,
66.19, 76.05 and these signals were assigned to C-4, C-3 and C-5. The first carbons of
quinide moiety C-1 occurred in downfield 77.12 ppm compare to other carbons of
quinide with smaller signal intensity. The six sets of olefinic carbons in the region as
it was expected. The first olefinic carbons occurred at 116.66, 116.88, 116.97 ppm
and assigned to C-9, C-18 and C-27. These signals followed by overlapping twelve
carbons of aromatic group. The signals occurred at 122.24, 122.35, 122.41, 129.45,
129.59 and 129.72 ppm assigned to C-13, C-15, C-22, C-24, C-31, C-33, C-12, C-16,
C-21, C-25, C-30 and C-34. The next set of carbons occurred at 131.70, 131.71 and
131.75 ppm. This group identified as carbons of aromatic group which hasn’t got any
hydrogen adjacent to it. These signals assigned to C-11, C-20, C-29 due to cross peaks
at 1 H 13 C-HMQC spectrum. The second set of olefinic carbons occurred just after
aromatic carbons where it was expected before. The signal at 145.13, 145.80 and
145.90 ppm assigned to C-10, C-19 and C-28 carbons due to chemical shift
consideration and the cross peaks which was observed at H 1 H-COSY and 1 H 13 C-
HMQC spectrum. The first set of carbonyl carbons found at 152.41, 152.62 and
152.70 ppm and this signals assigned to C-8, C-17 and C-26. Then the other three
carbonyl carbons occurred at 164.91, 165.23 ppm. By looking at the signal intensity
and the cross peaks at 1 H 13 C-HMQC spectrum the signal at 164.91 ppm identified as
overlapping two carbonyl carbons C-14 and C-23. Then the signal at 165.23 ppm with
one carbon intensity assigned to C-32. The very last part of carbonyl carbons of
coumaroyl moiety was occurred at 169.14 ppm with three carbon intensity and
assigned to C-35, C-36 and C-37. The carbonyl carbon of quinide moiety occurred at
the end of the spectrum at 171.32 ppm and assigned to C-7.
The infrared spectrum showed consistent signals at 1806, 1765, 1721 cm -1 (C=O),
1635 (C Ar =C Ar ), 1267, 1243, 1156, 1077 cm -1 (C-O) as the other spectral data.
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