This paper will focus on Cooperative learning in science education. Curcumin extract is subjected to 1H NMR, 13C NMR, and 2D -HSQC FT-NMR analysis for structure the 2D NMR specra may be obtained that indicate coupling between hydrogens and carbons to which they are attached. In this case it is called heteronuclear correlation spectroscopy (HECTOR, HSQC, or C-H HECTOR).

1. Cooperative learning :High resolution 13 C and 1HFT-NMR and2D 1H-13C HSQC ofCurcumin:
Mohammed Izmika, KassandraDorce, Mohammed Sherwani, and Samira Izmika
By Dr. Robert D. Craig,Ph.D
In this paper, student projects are given as an example on how to introduce FT –NMR into the
undergraduate curriculum.
We will incorporate NMR experiments that illustrate the application of high resolution NMR
spectroscopy to the structure determination of Anti-Cancer agents.
High resolution 13 C and 1H NMR , 13 C –distortionless enhancement by polarization transfer
(DEPT) , 2D 13C-1H correlated (HECTOR), and 2D 1H-1H correlated (COSY) spectroscopy
techniques will be used for elucidating skeletal arrangement of monomer units.
Applications that also use the 2D 1H-13C HSQC experiment are gaining more interest as a result
of the growing feasibility of acquiring these spectra routinely. The 2D HSQC experiment
contains additional information (i.e. 13C chemical shift) as well as easier identification of labile
and diastereotopic protons

2. This leaves only on-H containing C’s to
assign.
Introduction
There are several ways in which phase
This paper will focus on Cooperative sensitive data can be recorded. Phase
learning in science education. sensitive will be what will be discussed
below.
What is Cooperative learning? Cooperative
Learning is an instructional strategy that
Student became familiar with SpinWorks.
incorporates academic and social skill
This software must know how the data
learning. As science educators, we were recorded in order to process it
understand the critical importance for our correctly. It is also possible to adjust the
intermediate learners to be engaged in timings in a pulse sequence so that there is
their learningwhile developing socially no required F phase correction. This
1
acceptable communication skills approach is seen in most Varian NMR data.
For Varian data, SpinWorks guesses the F
1
detection mode from the name of the pulse
Curcumin is know for it ability to fight sequence. Most phase sensitive Varian
amyloid plaque and well as having positive pulse sequences are either hypercomplex
(States) detection (e.g. HSQC, TOCSY,
results in treating cervical and brain cancer .
NOESY) or echo-antiecho (e.g. gHSQC)
However, it is also know for it’s poor
bioavailabity.
Natural cancer agents such as Taxol and
Curcumin are isloated via ethanol extraction
procedure. They are futher purified by size Experimental
exclusion chromotography and HPLC
For the Varian 600mHz, 5mm NMR Sample
Their structure is confirmed by various tubes were used. The NMR sample tubes
solvents in FT-NMR experiments and were“L” Series 5mm NMR tubes (4.960 ±
Chemdraw NMR software. 0.006mm OD; 0.40mm nominal wall;
0.0025mm roundness). Spectra taken by
2D -HSQC FT-NMR Utilizes bond coupling the Varian 600 Mhz spectrometer used TMS
between H and C.and is extremely useful in as an internal standard. All spectra was
determining structure of organic processed from the Varian using
compounds. It also Eliminates all the H spinworksplatform.Thespecta was
containing C’s so this eliminates many C’s subsequently confirmed using Chemdraw
assignments (why carboxyl group CH2 do NMR. It was convinent to use Spinworks to
not appear!) analyze spectra. The
Spinworkssoftware,was created by Kirk

3. Marat. It provides us with excellentdata
analysis options andtabular results for ppm
shifts for both spectra. Curcumin is a red
powder after extraction is performed. This
red powder was successively subjected to
1
H NMR, 13C NMR, and 2D -HSQC FT-NMR
analysis for structure
determination (compound 1). See image
below

4. Results and discussion
Figure 1 and 2 are the 1H and - 13C of curcumin. The proton spectra give rises to 14
peaks. The carbon spectra displays 13 peaks
Figure 1: the proton spectra of curcumin acquired by the 600 mHzvarian spectrometer
For Curcumin, the proton (1H spectrum) shifts are as follows. 2 similar protons on the
aromatic groups give rise to shifts at 5.55ppm (aromatic C-OH). The benzene CH of
which there are 3, give rise to 7.16 ppm, 6.99 ppm and 6.79 ppm. On the hexadienone
bridge, between the two benzene rings (aromatic rings) are 2 pairs of equivalent
protons(chemdrawNMR was used to confirm this spectral assignment

5. Table 1 : Varian measurements of curcumin generated by spinworks
curcumin proton from Spin works curcumin carbon 13 from Spin works
Peak shift feq(ppm) Peak shift feq(ppm)
Carboxylic
1 7.616 Aromatic C-H 1 182.2 acid peak
2 7.59 Aromatic C-H 2 147.7 Alkene
3 7.271 Aromatic C-H 3 146.6 Alkene
4 7.27 Aromatic C-H 4 140.5 Alkene
5 7.143 Aromatic C-H 5 127.5 aromatic 13C
6 7.129 Aromatic C-H 6 123.8 aromatic 13C
7 7.063 Aromatic C-H 7 114.8 RCH=CH2 and R2C=CH2
8 6.954 1-Benzene 8 109.3 double bonded RCH=CHR
9 6.94 1-Benzene 9 107.6 double bonded RCH=CHR
10 6.502 1-Benzene 10 77.19 vinylic groups (R2C=C-R
11 6.476 1-Benzene 11 76.97 vinylic groups (R2C=C-R
Aromatic C-
12 5.859 OH 12 76.78 vinylic groups (R2C=C-R
Aromatic C-
13 5.812 OH 13 55.99 Alkyl 2o and 3o carbon
methoxy
14 3.962 OCH3 * missing ref xx 84.4 quartenary to Oxygen
* missing ref xx 72.9 quartenary to Oxygen
Liu, Sun, and Huang
Students also became familiar with the software Chemdraw NMR. Data from this
software was highly beneficial to assign and confirm spectra acquired by the varian

6. Table 2 :proton spectra of curcumin generated by
chemdraw NMR
curcumin proton from chemdraw
shift (ppm) atom index coupling partner constant and vector
Delta H
5.35 7
5.35 25
7.16 24
20 20 1.5 H-C*C*C*-H
6.99 21
H-C*C*-
20 7.5 H
7.16 6
20 20 1.5 H-C*C*C*-H
6.79
H-C*C*-
21 21 7.5 H
24 24 1.5 H-C*C*C*-H
6.99 3
H-C*C*-
4 4 7.5 H
6.79 4
H-C*C*-
3 3 7.5 H
6 6 1.5 H-C*C*C*-H
3.83 10
3.83 27
4.59 13
7.6 28
H>C=C<
30 15.1 H
7.6 29
H>C=C<
31 15.1 H
6.91 30
H>C=C<
28 15.1 H
6.91 31
H>C=C<
29 15.1 H

7. Table 3: proton assignment using chemdraw NMR
Curcumin chemcraw
OH=5.35 5.5 5.00. Aromatic C-OH
0.35 General correction
OH=5.35 5 Aromatic C-OH
0.35 General correction
CH=7.16 7.26 7.26
-0.49 1 –O-C
-0.17 1 –O
-0.04 1 –C=C
0.52 General correction
CH=6.99 6.99 7.26 1-Benzene
-0.11 General correction
-0.53 Aromatic C-OH
-0.55 General correction
CH=7.16 7.16 7.26
-0.49 1 –O-C
-0.17 1 –O
-0.04 1 –C=C
0.52 General correction
CH=6.79 6.79 7.26 1-Benzene
-0.44 General correction
-0.17 Aromatic C-OH
-0.04 General correction
CH=6.99 6.99
-0.11 1 –O-C
-0.53 1 –O
-0.05 1 –C=C
0.42 General correction
CH=6.79 6.79 7.26 1-Benzene
-0.44 General correction
-0.17 Aromatic C-OH
-0.04 General correction

8. Analysis of 13 Carbon for Curcumin:
In some important ways 13C spectra are usually less complex and easier to interpret
than the 1H NMR spectra.
The interpretation is greatly simplified because each unique carbon atom only produces
one 13C peak.
The low natural abundance of 13C nuclei and its inherently low sensitivity also have the
effect that this spectra can only be obtained on pulse FT NMR spectrometers. The
Varian 600 mHz being highly suitable for this purpose.
Where as carbon-carbon splitting does not occur in 13C NMR spectra, hydrogen atoms
attached to carbon can split 13C NMR signals into multiple peaks. It is possible to
eliminate signal splitting by 1H -13C coupling by altering instrument parameters to do
so.
Students found the concept of 13C chemical shifts highly intriging. Relatively higher
electron density around an atom shields the atom from the magnetic field and causes
the signal to occur upfield (lower ppm and to the right) in the NMR spectrum.
For example, carbon atoms that are attached only to other carbon and hydrogen atoms
are relatively shielded from the magnetic field by the density of electrons around them,
and, as a consequence carbon atoms of this type produce peaks which are upfield in 13C
NMR spectra

9. Below is the proton spectra of curcumin acquired by the 600 MHz Varian spectrometer
Figure 2: the carbon 13 spectra of curcumin acquired by the 600
mHzvarian spectrometer
When analyzing the hector spectra – it might be first beneficial to designate the
carbon spectral lines first. Then, sweep these lines across the proton specta.
For the 13 spectra of curcumin, it is better we see this before address the Hector
spectra some peaks fromThe peak at 55.954 is due to alkyl 2o or alkyl 3o carbon.
Alkyl 2o and 3o carbon reside in the 50 ppm region, so obviously the 55.985 ppm
corresponds to such a group. There are three peaks at 77.18662, 76.96907 and
76.78016. these belong probably to vinylic groups on the hexadione bridge
(R2C=C-R). The peaks from 109 to 107,(109.3 and 107.6) Are probably due to
double bonded carbons also on the hexadione bridge. They are for RCH=CHR
carbon 13 resonances. Similar RCH=CHR carbon 13 resonances, RCH=CH2 and
R2C=CH2 from the 127.5 ppm, 123.8 ppm, 122.6 ppm and 114.8 ppm. this will
also encompus the peaks at 147.7 ppm, 146.6 ppm and 140.5 ppm. Lastly ,
aromatic 13C are from 120 to 135 ppm.

10. Analysis of -2D 1H - 13C HSQC spectra Carbon for curcumin:
Below is Figure 3 and 4 they are the 2D1H - 13C HSQC spectra ofCurcumin
Figure 3 the 2D 1H - 13C HSQC spectra ofCurcumin

11. Figure 4 (zoomed at 200%) are the 2D 1H - 13C HSQC spectra of Curcumin.
The 2D NMR specra may be obtained that indicate coupling between hydrogens and
carbons to which they are attached. In this case it is called heteronuclear correlation
spectroscopy (HECTOR, HSQC, or C-H HECTOR).
When ambiguities are present in one-dimensional 1H and 13C NMR spectra, a HECTOR
or HSQC spectrum can be very useful for assigning preciscely which hydrogens and
carbons are producing their respective peaks. In a HSQC spectrum a 13 C spectrum is
presented along one axis and a 1H spectrum is shown along the other. Cross peaks

12. relating the two types in a HSC spectrum indicate which hydrogens are attached to
which carbons in a molecule, or vice versa.
These cross peaks correlations are the result of instrumental parameters specified on
the NMR spectrometer. If imaginary lines are drawn from a given cross peak in the x-y
field to each respective axis,. The cross peak indicates to the hydrogen giving rise to the
corresponding 1H NMr signal on one axis and is coupled or attached to the carbon that
gives rise to corresponding 13C NMR signal on the other axis. Thus, it is readily
apparent which hydorgens are attached to which carbons
Let’s dive right in, as the research students have provided the spectra and determine
the HSQC for Curcumin, with the aid of the ChemdrawNMR software, and previous scan
of curcumin (proton and 13C). It is beneficial to keep these spectra on hand. The
Spinworks software, created by Kirk Marat.also provides us with excellent ppm shifts for
both spectra
Working from top down, and left to right, the HSQC for curcumin reads as such. The
first peak evident in the spectra is 13C at 55.934 ppm, And crossed with
Proton(designed 14) at 3.9620 ppm. The next peak is with Proton(designed 12) at
5.8592 and a 13 C at 101 ppm
This hydrogen must be attached to the OH group , or might be the hydrogen in between
the carbonyls on the hexadione bridge.
The carbon 13 peak at 109.3 cross with several protons. Referenced with the spinworks
data table for curcumin proton data taken the Varian 600 MHz we have for Peak 3 in the
HSQC specta with Peak 12 at 5.8592 ppm And Peak 13 at 5.8124 ppm in the proton
spectra. Please refer to table one for the spinworks data.
The carbon 13 peak at 109.3 ppm coupled with a hydrogen (peak 5 at 7.1427 ppm) is an
aromatic hydrogen. This hydrogen resides on a benzene ring, and is obviously
confirmed by coupling with an aromatic 13C at 109.3 ppm
We will shortly find this of high interest.
It is this hydrogen that will be effected in the carboxyalated form of curcumin. The
carbon peaks at 122.6 and 123.8 ppm with peak 3 and 4 (off diagonal) of the proton
data gives some modest peaks in the specta. Also evident are Peak 3 (122.6 ppm 13C
with (6.473 ppm 1H, 6.503 ppm 1H ) And, With peak 7 and 8 (shown in the off diagonal)
coupling 123.8 ppm 13C with (6.473 ppm 1H , 6.503 ppm 1H) . These hydrogens are on
aromatic ring next to hydroxyl groups. A Carbon of 114 ppm is appropriate to be

13. adjacent to these hydrogens. As referenced by the ChemdrawNMRsoftwareplatfom”The
benzene CH of which there are 3, give rise to 7.16 ppm, 6.99 ppm and 6.79 ppm. “On
the hexadienone bridge, between the two benzene rings (aromatic rings) are 2 pairs of
equivalent protons, (see table 2). The software also allows for shift corrections.
With peak 1 and 2 (on diagonal) (7.1427 ppm 1H , and 7.1290 ppm 1H ) probably refers
to These hydrogens that are H-C=C-H on a benzene ring. 123.8 ppm is reminiscient of
the conjagated ring as well. For a 13C signal in the spectra at 101 ppm, thecoupling with
With peak 12 (5.8592 ppm) and 13 (off diagonal) (5.8124ppm 1H ) is rather confusing.
Most likely,these 2 similar protons on the aromatic groups give rise to shifts at 5.55ppm
(aromatic C-OH).
CONCLUSION
• Using information from 1H NMR data alone is not a new concept. However,
applications that also use the 2D 1H-13C HSQC experiment are gaining more
interest as a result of the growing feasibility of acquiring these spectra routinely.
The 2D HSQC experiment contains additional information (i.e. 13C chemical shift)
as well as easier identification of labile and diastereotopic protons. I would like
to thank the students and staff at the college of Staten Island, CUNY for making
this work possible. I find cooperative learning to be very important because it is
crucial for our students to learn to work in groups. This not only helps develop
their social skills, but also enhances their ability to develop the skills necessary to
work collaboratively when they enter the work force.