3. Table of Contents
1. Background
2. Projected Solution
3. Methodology
4. Conclusion
5. Personal Development
6. Acknowledgements
7. Questions
4. Background
• Chronic pain affects 116 million Americans per
year 1
• Opioid drugs are the primary prescribed pain-
killers
1O’Reilly, Kevin B. American Medical News. 2011
5. Background
• Opioid drugs have several side effects:
- digestive problems2
- addiction3
- tolerance3
As the dosage increases, the side effects increase until the point that
the side effects outweigh the benefits
2Chan, Lingtak-Neander. Nutrition Issues in Gastroenterology. 2008
3Stuckert, Jeffery. Psych Central. 2011
6. Projected Solution
• Previous research has discovered that the
Neuropeptide FF antagonist receptors can
prevent morphine-induced tolerance
• The use of a dual-acting compound with
Opioid & NPFF receptors looks promising:
-opioid drug use without tolerance
16. Methodology
• Because this synthesis required multiple steps,
after each step, verification had to take place
in before starting the next reaction
-in order to determine it was actually the desired
product
-make sure there were no impurities
17. Methodology
Thin Layer Chromatography (TLC)
- used to determine Rf value
Rf value = distance product traveled
distance solvent traveled
= 6.25 cm
8.00 cm
= 0.781
18. Methodology
TLC is also used to make
comparisons:
-the compound is the same across,
verifying that the different tubes
from column chromatography
contain the same compound.
20. Conclusion
• We successfully modified VBJ192 into an amidine derivative
• NMR verified
• Pharmacological evaluation will be performed on this compound
21. Personal Development
1. Honed research/lab skills
2. Delved into Medicinal Chemistry
3. Application of prior information
4. Patience
http://www.amednews.com/article/20111017/profession/310179937/2/
http://www.iom.edu/activities/publichealth/painresearch/pain-care-improvements-recommended-in-iom-report.aspx
***So what’s the big deal? We have Americans in pain, and we have opioids to fight their pain…
2. http://www.medicine.virginia.edu/clinical/departments/medicine/divisions/digestive-health/nutrition-support-team/nutrition-articles/ChanArticle.pdf
--opioid receptors are also found in the gastrointestinal tract; causes issues with the normal motility and secretory functions within the tract
3. http://psychcentral.com/lib/opioid-dependence-and-withdrawal/0008507
--Opioid addiction is a disease of the brain. Repeated use of an opioid leading to opioid dependence causes long-term changes in both the structure (the architecture of the brain) and the way the brain functions (the biochemistry of the brain). Many use it outside of the prescription directions.
4.SAME AS 3
Tolerance: need more of the opioid to get the desired effect
the GI issues become worse with the increase in dosage – making the side effects worse than the pain-relieving benefits
Opioid drugs, such as morphine, have to be increased overtime to continue delivering an adequate amount of pain relief
-- previous reseach shows that we do have a possible solution. If we act on the NPFF system in coorelation with the opioid system, then tolerance will not develop.
No tolerance means no increased dosages. No increased dosages means less addiction and less harm to the GI tract.
--Previous research within our own lab shows that compound VBJ192 works due to testing performed on mice. However, it only works when injected directly into the brain. Noone wants to inject shots into their brain. Need to find a drug that will work orally. That’s where the BBB comes into play. The BBB is very picky. Does not work if something is
1.
That’s where the BBB comes into play. The BBB is very picky. Does not work if something is too highly charged, too large, not lipid soluble..
Also, if it is too basic. AND, we know that 5 Nitrogens within a structure is the max number of nitrogens that can enter the BBB.
Therefore, we would like to use SAR. Once we change different parts, we can try & enter the BBB. SAR will allow us to determine what part is necessary to have the desired function
As well as help us change structures to one that will pass BBB more efficiently.
For my compound, we used SAR and changed from guanidine to aminidine.
WHY?
amidine functional group has been shown to be able to penetrate the Blood-Brain Barrier (BBB) from peripheral administration when it has been substituted for the guanidine functional group.
Hoping the rest of the compound will work as VBJ192 did, but be able to penetrate BBB so we can make oral drugs.
Bromobenzene was added to triphenylphosphine, was dissolved in toluene, and refluxed at toluene’s BP overnight to yield the benzyltriphenylphosphonuim salt, which
Is needed to proceed with the Wittig Reaction.
97% yield
Used the salt made, combined it with benzylpiperidone & refluxed overnight in a solution of LDA. LDA was used in order to produce the YLIDE. (+ and - charge next to each other)
It was very important, at the step, to perform the reflux under argon, due to LDA’s reactivity with our air. LDA will take a Hydrogen, which destroys LDA’s ability, which stops the reaction
from taking place. Produced our desired compound, 1-benzyl-4-benzylidenepiperidine, and by product triphosphoniumoxide. After separating the two we proceeded..
42.2% yield
To bromination. This was a cool step. The bromine was a dark orange color with fuming orange vapors.
--let it stir, heated & added NaOH and MeOH. Did purification to just have desired product without any starting materials.
80.7% yield
We took our brominated product and reacted it with cynaopheynlboronic acid and tetrakis(triphenylphosphine) palladium. The palladium is air sensitive (used argon) as well as light sensitive. (Also, side note – makes a really pretty neon color show when put under UV light for TLC). So, we had to wrap the flask in foil to prevent the reactants from being exposed to light as it refluxed over night. This reaction added the phenyl group with the cyano to our compound. 52.1% yield
Then, came the last part of the synthesis. Converting the cyano group into amindine. THEORETICAL YIELD:
Gravity filtration in order to separate the different compounds of the mixture. Used this to separate the desired product from byproduct in Wittig reaction.
Chromotography to separate the compound for purity: use different mobile phases based of polarity that allowed for separation. We didn’t use pressure. Very time-consuming.
So, we made the compound, purified it, then verified it was the actual desired product in a purified form.
Different vials from Chromography. Used a sample of what we new was the compound (from previous column)
-verifies the mass of the compound
-shows that there aren’t detectable impurities because of single peak
. If the in vitro assays are in close agreement with VBJ-192, MCM1 will be investigated in vivo for antinociceptive activity through peripheral administration in Core D of the COBRE program, followed by investigation at Torrey Pines for acute antinociceptive tolerance.
--learned to be patient because chemistry doesn’t work on a planned schedule
--you will mess up; it’s a part of the practice.
Ex. Dropped stir bar into chemical waste bucket.
