The Study of Triazine Antimicrobial Compounds
Jillian GreenawayNew York University
Dr. Neville Kallenbach
ObjectiveThe goal of this project is to synthesize Triazine compounds using biomimetics and test how well they inhibit the growth of Bacillus Subtilis.
ProblemPeptides, when used in our bodies to kill bacteria, can be digested by protein digesting enzymes. In a result of this, we had to think of another strategy to inhibit bacterial growth. This is when we thought of biomimetics.
BiomimeticsBiomimetics also known as Bionics, is the implementation of methods found in nature to the study of modern technology. We used biomimetics, specifically to make a synthetic material mimic a naturally occurring substance by giving it positively charged and hydrophobic properties.
HypothesisUsing biomimetics, an organic molecule can act the same way as a protein with similar properties. The properties for antimicrobial activity are an overall 2+ charge and 2 bulky hydrophobic groups. If enough of this compound with these characteristics is associated with the membrane, it can break the membrane and kill the bacteria.
Triazine LibrariesThe lab workers synthesized triazine libraries to test on Bacillus Subtilis by using Combinatorial Chemistry, which is the act of mixing products. Libraries are groups of the same compound synthesized in various ways. The following charts depict the two groups of triazine libraries used.
Group 1 Compounds
This plate was chosen for the many bulky hydrophobic groups. The third functional group used in this library is adamantane.
R1 Structure R2 Structure
A 1
B 2
C 3
D 4
E 5
F 6
G 7
H8
I
J
NH2
OH
NH2
OH NH2
NH2
NH2
OH
OH OH
NH2
OH NH2
OHOH
NH2
O
O
NH2
NH2
OO
NH
Bz
OMe
NH2
NH2
NH2 OH
NH2
NH2
NH2
NH2
NH2
N
N
N
NH
R1 R2
Positive Charge – Group 2
N
N
N
NH
R1 R2
OO
NH2
R1 Aryl/Alkyl R2 Amine
A 1
B 2
C 3
D 4
E 5
F 6
G 7
H 8
9
ClN NH2
N
NH2
NH
N
N
O
NH2
N NH2
NNH2
N
NH2
N
NH2
NNH
OH
This group was chosen to have sufficient positive charge and also, hopefully, to have enough hydrophobic bulk to be active.
Methods and MaterialsIn order to determine which compound kills bacteria efficiently, we ran assays or tests.1. First we grew the bacteria in an incubator shaker for several hours.2. Secondly, we set up plates containing twenty-four wells.
Each well contained 800 microliters of plain media, Bacillus Subtilis, sodium phosphate buffer, and a different concentration of the triazine compound. The amount of phosphate buffer and compound together equaled 150 microliters. All the wells contained 50 microliters of cell culture, which included Bacillus Subtilis and Tryptic Soy Broth. I allowed all the plates to grow for six hours.
3. After six hours I ran all the samples through the spectrophotometer. With a push a button we were presented with the samples’ light absorbance in a numerical value. I took this number and computed it into the following equation.
1- (Average Absorbance from the compound/ Average absorbance
from the control) X 100
This equation results in the inhibition percentage. Therefore, if the percentage is high then the compound worked efficiently. On the other hand, if the percentage inhibition is low, the compound did not stop the bacteria from growing.
Results from Group 1
A B C D E F G H I J
1 * 73.1 4.1 77.3 54.2 4.3 38.3 28.0 40.8 44.3
2 * 99.4 88.5 * 29.3 84.1 33.7 96.6 44.9 39.2
3 3.9 19.1 42.0 11.5 * 97.2 82.5 97.8 12.6 10.5
4 0.7 39.2 * 44.0 5.6 72.4 67.7 * 27.8 27.4
5 9.3 * * 33.9 26.3 7.5 9.2 6.7 44.7 30.2
6 * 1.5 10.5 23.9 94.1 3.9 * * 15.6 18.3
7 * 5.5 97.2 23.7 17.1 29.9 7.2 100 15.2 10.4
8 50.1 8.1 98.1 69.1 22.3 99.6 99.6 * 7.6 4.4
* = 0% Inhibition
% Inhibition at 100M
Positive Results from Group 1 A B C D E F G H I J
1 * 73.1 4.1 77.3 54.2 4.3 38.3 28.0 40.8 44.3
2 * 99.4 88.5 * 29.3 84.1 33.7 96.6 44.9 39.2
3 3.9 19.1 42.0 11.5 * 97.2 82.5 97.8 12.6 10.5
4 0.7 39.2 * 44.0 5.6 72.4 67.7 * 27.8 27.4
5 9.3 * * 33.9 26.3 7.5 9.2 6.7 44.7 30.2
6 * 1.5 10.5 23.9 94.1 3.9 * * 15.6 18.3
7 * 5.5 97.2 23.7 17.1 29.9 7.2 100 15.2 10.4
8 50.1 8.1 98.1 69.1 22.3 99.6 99.6 * 7.6 4.4
: >90% inhibition : >80% inhibition
Results from Group 2
1 2 3 4 5 6 7 8 9
A 5.6 8.1 0.4 * 5.5 9.7 99.7 9.6 4.6
B 99.6 6.2 14.2 4.4 8.5 * 99.5 * *
C 84.3 15.2 83.4 21.3 100 32.6 99.9 10.6 72.1
D 23.6 16.4 15.0 12.5 7.3 * * 8.3 6.2
E 99.0 46.7 97.9 78.5 97.9 98.4 98.1 * 7.6
F 85.2 10.6 99.0 * 97.3 * 98.9 1.4 *
G * * * * 1.0 1.8 * * *
H 15.8 2.0 6.3 * 7.1 * 99.4 * 28.6
% Inhibition at 100M
Results from Group 2
1 2 3 4 5 6 7 8 9
A 5.6 8.1 0.4 * 5.5 9.7 99.7 9.6 4.6
B 99.6 6.2 14.2 4.4 8.5 * 99.5 * *
C 84.3 15.2 83.4 21.3 100 32.6 99.9 10.6 72.1
D 23.6 16.4 15.0 12.5 7.3 * * 8.3 6.2
E 99.0 46.7 97.9 78.5 97.9 98.4 98.1 * 7.6
F 85.2 10.6 99.0 * 97.3 * 98.9 1.4 *
G * * * * 1.0 1.8 * * *
H 15.8 2.0 6.3 * 7.1 * 99.4 * 28.6
Positive Results Highlighted
: >90% inhibition : >80% inhibition
Frequency of Effectiveness (G1)R1 Structure Freq. R2 Structure Freq.
A 0 1 0
B 1 2 4
C 3 3 3
D 0 4 0
E 1 5 0
F 3 6 1
G 2 7 2
H 3 8 3
I 0
J 0
NH2
OH
NH2
OH NH2
NH2
NH2
OH
OH OH
NH2
OH NH2
OHOH
NH2
O
O
NH2
NH2
OO
NH
Bz
OMe
NH2
NH2
NH2 OH
NH2
NH2
NH2
NH2
NH2
Frequency of Effectiveness (G2)R1 Structure Freq. R2 Structure Freq.
A 1 1 4B 2 2 0C 4 3 3D 0 4 0E 5 5 3F 4 6 1G 0 7 6H 1 8 0
9 0
Cl N NH2
N
NH2
NH
N
N
O
NH2
N NH2
NNH2
N
NH2
N
NH2
NNH
OH
AnalysisGroup one did not have much positive results
because of the lack of positive charge in the library.
Group 2 had more positive results than Group one because it had both positively charged and hydrophobic groups. But it is possible that we’ve gone too far in the other direction and that there is now enough positive charge, but no longer sufficient hydrophobic bulk.
ConclusionWe analyzed the data and designed
a new library.The following chart depicts the
functional groups for these libraries.
“Desirable” Functional Groups Hydrophobic Groups:
Plate 1, # 2:
Plate 1, # 3:
Plate 1, # 8:
Plate 1, # C:
Plate 1, # F:
Plate 1, # H:
Plate 2, # C:
Plate 2, # E:
Plate 2, # F:
Charged Groups:
Plate 2, # 7:
Plate 2, # 1:
Plate 2, # 5:
Plate 2, # 3:
N
NH2
N
NH2
N NH2
N NH2
OH NH2
Cl
OH OH
NH2
OHNH2
O
NH2
NH2
OMe
NH2
Proposed New Library
In the new library, we would like to use a triazine with adamantane, then use the selected positive groups for the R1 position, and cross them with both the hydrophobic and charged moieties in the R2 position. This should help us to determine the best balance of charge vs. hydrophobicity.
R1 Structure R2 Structure
AA
B
BC
D
C1
2
D3
4
5
6
7
8
9
N
NH2
N
NH2
N NH2
N NH2
OH NH2
Cl
OH OH
NH2
OHNH2
O
NH2
NH2
OMe
NH2
N
NH2
N
NH2
N NH2
N NH2
N
N
N
NH
R1 R2