Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter in the brain that has an enormous influence over many brain functions. It is synthesized, from the amino acid L-tryptophan, in brain neurons and stored in vesicles. Serotonin is found in three main areas of the body: the intestinal wall; large constricted blood vessels; and the central nervous system. The most widely studied effects have been those on the central nervous system. The functions of serotonin are numerous and appear to involve control of appetite, sleep, memory and learning, temperature regulation, mood, behavior (including sexual and hallucinogenic behavior), cardiovascular function, muscle contraction, endocrine regulation, and depression.
The activity of serotonin arises in the brainstem from clusters of neurons known as the raphe nucleus. From the brain, serotonin neurons extend to virtually all parts of the central nervous system making the branching of the serotonin network the most expansive neurochemical system in the brain. The importance of this network becomes apparent when considering each serotonin neuron exerts an influence over as many as 500,000 target neurons. Due to the widespread distribution of serotonin in the nervous system, it is not surprising that this neurotransmitter can be linked to many types of behavior.
Of the chemical neurotransmitter substances, serotonin is perhaps the most implicated in the treatment of various disorders, including anxiety, depression, obsessive-compulsive disorder, schizophrenia, stroke, obesity, pain, hypertension, vascular disorders, migraine, and nausea. A major factor in the understanding of the role of 5-HT in these disorders is the recent rapid advance made in understanding the physiological role of various serotonin receptor subtypes. There are at least four populations of receptors for serotonin: 5-HT1, 5-HT2, 5-HT3, and 5-HT4. The physiological function of each receptor subtype has not been established and is currently the subject of intensive investigation.
This was taken from Serotonin
Also called Normelatonin, this is an intermediate step in the production of melatonin from serotonin.
This is the molecule serotonin that can be rotated around. It is a fairly simple model in that it is straightforward and has no weird angles and is just in a two dimensional plane.
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In the table below are the values I got from WebMo concerning the Free Energy (G) and the Enthalpy (H).
| Compound | Free Energy (KJ/mol) | Enthalpy (KJ/mol) |
| C2H4O(acetyl group) | -92.45601928 | -13.09474201 |
| C10H12ON2(Serotonin first conformation) | 461.2614998 | 595.4642287 |
| C10H12ON2(Serotonin second conformation) | 461.2614998 | 595.4721044 |
| C10H12ON2(Serotonin third conformation) | 456.8012017 | 596.522204 |
| C12H14N2O2(N-acetylserotonin first conformation) | 378.035856 | 540.1344808 |
| C12H14N2O2(N-acetylserotonin second conformation) | 373.9719705 | 531.9463291 |
The table below shows all the combinations of reactions that can take place. To save space, the names of the molecules have been abbreviated as follows: Acetyl Group= Ace, Serotonin Conformation 1= Sero1 and so on for the 3 conformations of serotonin, N-Acetyl Serotonin 1 and N-Acetylserotonin 2= Acsero1 and Acsero2 respectively.
To find the Change in Free Energy, I subtracted the combined Free Energy of the Reactants (Ace and Sero) from the Free Energy of the Product (Acsero). The same is true as to how I found the Change in Enthalpy, just substitute the word Enthalpy for Free energy in the above sentence and it's all good.
| Reaction | Change in Free Energy (KJ/mol) | Change in Enthalpy (KJ/mol) |
| Ace + Sero1 --> Acsero1 | 9.23037548 | -42.23.23500589 |
| Ace + Sero2 --> Acsero1 | 9.23037548 | -42.24288159 |
| Ace + Sero3 --> Acsero1 | 13.69067358 | -43.29298119 |
| Ace + Sero1 --> Acsero2 | 5.16648998 | -50.42315759 |
| Ace + Sero2 --> Acsero2 | 5.16648998 | -50.43103329 |
| Ace + Sero3 --> Acsero2 | 9.62678808 | -51.48113289 |
From the first table it is pretty easy to see that the Acetyl group has the best and probably most realistic results. This is probably because it is such a small molecule that it would be difficult to come up with a drastically different conformation.
As for the other molecules, I wish I had had more time to fine tune my models, but they are what they are, and the results aren't terrible. By some odd way or another though, conformations 1 and 2 of Serotonin ended up with the exact same Free Energy while having slightly different Enthalpies. From this, it can be assumed the first conformation is slightly better because its enthalpy is lower by about a hundreth of a KJ/mol.
As for the N-acetylserotonins, it was pretty apparent that the second conformation is better. This can be shown by looking at the molecules individually, or when taken as part of the reaction. All three reactions that involved the second conformation of N-acetylserotonin were significantly less than their counterparts using the first conformation.
Had there been more time, it would have been interesting to tweak these molecules even more and try and find the best structures and run more demanding calculations on them.
Thanks for looking at my site, and I will see you in the future!
