How do Substituted Functional Groups affect Substances?

[Cface]

Bit of basic Org. Chemistry/Pharmacology help needed!

How is it that substituted functional groups affect the subjective effects of a substance so drastically?

i.e. 4-MMC > 4-MEC > 4-FMC.
While 4-MMC has drastically stronger acute subjective effects (i.e. strong euphoria, mild-strong stimulation, and strong entactogen/empathogenic qualities) when compared to 4-MEC or 4-FMC...
While 4-FMC has virtually no euphoria or entactogen qualities compared to 4-MMC. And 4-MEC containing only mild euphoria and entactogen/empathogen qualities.

 

[nuke]

It depends on what the modified compound binds to in the body (enzymes, receptors, transcription factors) and by the strength of the binding... For starters the fluorine in 4-FMC is much more electronegative than the methyl group, you should be able to predict some difference in electrostatic interactions with amino acids in proteins because of that.

 

[Hammilton]

They alter the ligand's interaction with the receptor, for one, and for substances that do a variety of things, they cause these changes unevenly. What benefits SERT affinity may hurt VMAT2 and DAT, may benefit 5HT2a, etc.

Then there are the obvious other issues like ability to penetrate the blood brain barrier, rate of metabolism, metabolic products, etc.

 

[sekio]

How do Substituted Functional Groups affect Substances used as Drugs?

This is perhaps the oldest question in medicinal chemistry - welcome to the wonderful world of structure-activity relationships! It ain't pretty or simple at all.

 

[vecktor]

this is known as SAR or QSAR, there are very good descriptions of the principles on wikipedia and elsewhere online where the physical and chemical properties of the substituent are correlated to the pharmacology.

The targets for cathinones (generally toxic and low potency compounds) are the three monoamine transporters NERT SERT DAT and some of the monoamine receptors. changing the nature and position of the substituent changes the affinity for the transporters, changes the way the substance interacts with the transporters and perhaps more importantly it effects the PK (pharmacokinetics)

the best thing for the OP to do is look up the things in bold, read everything they find and then come back with questions at a higher level.

 

[Cface]

Hey thanks for highlighted material vecktor! Got bit of material to read now, thanks for the direction