Sulfanilamide Derivatives Effectiveness on Growth
Inhibition in E. coli and S. aureus
Tiffani Ream, Department of Biological Sciences, York College of PA
Space filling model of sulfanilamide.
http://www.ljmilitaria.com/1c77fe2c0.jpg
http://www.chm.bris.ac.uk/motm/sulfanilamide/sulfa1.gif
Introduction
Results
Results
Acetanilide
Area of Inhibition in Sulfanilamide Derivatives in E. Coli
Area of Inhibition in Sulfanilamide Derivatives in S. aureus
28000
28000
Ammonia
N-butylamine
Sec-butylamine
Standard Sulfanilamide
20000
16000
12000
8000
20000
-9.0
-8.5
-8.0
-7.5
-7.0
-6.5
-6.0
16000
12000
8000
0
-9.5
-5.5
-9.0
N-butylamine
Sec-butylamine Piperidine
Sec-butylamine (EC50=178.70) was more
effective than N-butylamine (EC50=257.50)
in E. coli only. N-butylamine (EC50=47.36)
was 1x105 times more effective in S. aureus.
-8.5
-8.0
-7.5
-7.0
-6.5
-6.0
-5.5
Log Concentration (ug/mL)
Log Concentration (ug/mL)
Ammonia
Morpholine
Figure 1. Comparison of area of inhibition between E. coli (left) and S. aureus(right)
in ammonia, n-butylamine, sec-butylamine derivatives of sulfanilamide and the
standard.
Means (n=6) and standard of error were calculated for each
concentration. An EC50 for each derivative and the standard sulfanilamide was
determined from these graphs.
Derivatives
Conclusion
Sulfanilamide is the most effective
compound in E. coli, while Morpholine is
more effective in S. aureus.
Antibiotic Disks (0-1000 µM)
Area of Inhibition in Sulfanilamide Derivatives in E. coli
Area of Inhibition in Sulfanilamide Derivatives in S. aureus
18000
Morpholine
Piperidine
Standard Sulfanilamide
14000
12000
10000
8000
6000
4000
-9.0
-8.5
-8.0
-7.5
-7.0
-6.5
-6.0
-5.5
Determine EC50
1. Is the standard sulfanilamide the most effective
sulfa drug?
2. Are trends evident within the different
sulfanilamide derivatives?
8000
6000
4000
Summary
0
-9.5
-9.0
-8.5
-8.0
-7.5
Table 1. EC50 Table of Sulfanilamide and Sulfanilamide derivatives.
a=
3. Do differences between gram positive and gram
negative bacteria exist?
10000
-7.0
-6.5
-6.0
Figure 2. Comparison of area of inhibition between E. coli (left) and S.
aureus(right) in morpholine and piperidine derivatives of sulfanilamide and the
standard. Means (n=6) and standard of error were calculated for each
concentration. An EC50 for each derivative and the standard sulfanilamide was
determined from these graphs.
Compound
Sulfanilamide
Ammonia
N-butylamine
Sec-butylamine
Morpholine
Piperidine
Questions Asked
12000
Log Concentration (ug/mL)
Log Concentration (ug/mL)
Measure zone
of inhibition
14000
Branched carbon chains are more
effective in E. coli, while a straight chain
has a lower EC50 in S. aureus. More of a
contrast in effectiveness of chain length is
evident in S. aureus.
2000
2000
0
-9.5
Morpholine
Piperidine
Standard Sulfanilamide
16000
Area of Inhibition (pixels)
E. coli
Polar substitutents are more effective than
non-polar functional groups.
18000
16000
S. aureus
Sulfanilamide is the most effective
compound in E. coli (EC50=10.78 µM),
while the morpholine derivative is most
effective in S. aureus (EC50=40.82 µM).
Morpholine is 3x105 times more effective
than Piperidine in both gram positive and
gram negative.
4000
4000
0
-9.5
Ammonia
N-butylamine
Sec-butylamine
Standard Sulfanilamide
24000
Area of Inhibition (pixels)
Area of Inhibition (pixels)
24000
Area of Inhibition (pixels)
Sulfa drugs have been used in medicine
since 1932 when Farbenindustrie patented
Protonsil (Williamson, Mindard, & Masters
2007).
The original sulfanilamide was
synthesized in 1908, along with thousands of
derivatives. In 1940, Domagk won the Nobel
Prize for his research in sulfanilamide
derivative development. However, due to the
technology of the time, most of the papers and
research he and other performed is not
accessible or readily available.
Sulfa drugs are competitive inhibitors of
p-aminobenzoic acid (PABA) (Woods 1941).
Bacteria require PABA in the synthesis of folic
acid, which is crucial for cell replication.
Normally, PABA binds to dihydropteroate
synthetase; however, when sulfanilamide is
present, competition occurs between PABA
and the drug (Yoneeyma & Katsumata 2006).
The
resulting
compound
of
sulfanilamide/dihydropteroate
synthetase
complex is not functional in the folic acid
synthesis pathway, thus causing cell cycle
arrest.
A standard practice in pharmaceutics is
to take an effective drug and modify it to
uncover a more efficient product or one with
more suitable qualities such as solubility or
polarity.
To do this, chain lengths are
modified and functional groups are added.
The objective of this study is to examine
derivatives of sulfanilamide for a more
effective compound. Both chain lengths and
functional groups were varied in this study in
the attempt to find a more effective derivative
of sulfanilamide.
Methods
µM
E. coli
10.78a
9.47
257.50
178.70
19.99
5.91x106
S. aureus
No fit
145.8
47.36
5.16x106
40.82
1.23x108
-5.5
The parent compound, sulfanilamide, is the
most effective in E. coli, while the morpholine
derivative is most effective in S. aureus.
Due to the disparity between gram positive
and gram negative, further research is
necessary to determine the cause. Structural
differences in the dihydropteroate synthetase or
the structural differences of the cell wall may
be the cause of these different results.
Literature Cited
•Williamson, K.L., R.D. Minard, and K.M. Masters.
2007. Macroscale and Microscale Organic
Experiments. Houghton Mifflin: Boston, MA.
•Woods, W.B. 1941. Studies on the Antibacterial
Action of Sulfonamide Drugs. JEM. 369-381.
•Yoneyama, H. and R. Katsumata. 2006. Antibiotic
Resistance in Bacteria and Its Future for Novel
Antibiotic Development. Bioscience, Biotechnology,
Biochemistry. 70.5, 1060-1075.
Acknowledgments
Area of Inhibition Measured
I would like to thank Dr. Kaltreider and Dr. Halligan for all of their help
and guidance in this project. I would also like to thank Brian Kanaskie
and Bethany Remeniuk for their help in the lab.