This two part post concerns the drugs often sold under the term “Bath Salts”. In this first instalment I shall describe the structural chemistry of such drugs. In the second (coming Friday!), the drugs mechanism of action shall be detailed.
To the average Joe or plain Jane, Bath Salts may just be that go-to present for your Nan at Christmas. However, Bath Salts is also an umbrella term for a whole host of psychoactive and stimulatory compounds resembling a fine white powder which can be bought legitimately over the internet, in stores stocking “legal highs” or from dealers on the street. They are otherwise advertised as “research chemicals” or “novel psychoactive drugs”.
These drugs are synthetic analogues of cathinone, a stimulatory compound found naturally in the plant Khat. This plant is traditionally chewed socially in many cultures owing to its euphoric and excitatory effects. Since 3 July 2013, Khat is illegal in the U.K and is designated as a class C drug. However, due to the vast quantity of analogues, there are many available alternatives on the illicit market. They can be taken orally, by insufflation (snorting) or intravenously.
Ingestion leads to an improved mood, varying levels of euphoria, a sense of increased alertness among other pleasurable feelings but adverse effects are common, especially with the inexperienced. These include hallucinations, paranoia, anxiety as well as suicidal tendencies. They have also been blamed for some shocking incidents including a case in which a mans face was ravaged by a junkie. Check out this piece of anti-drug propaganda put together by the American Navy. It may be hilarious, but its message is clear:
Cathinones and its analogues are structurally similar to amphetamines, a more commonly known stimulant. Let’s do some chemistry:
Cathinones consist of:
1. An aromatic ring. In this, 6 carbon atoms are arranged into a regular hexagon connected alternately by single and double covalent bonds.
A “covalent bond” is formed through the sharing of electrons. The easiest way to visualise an atom, though not strictly true according to most recent understanding, is as follows. Protons and neutrons are localised within a central nucleus and are orbited by electrons. These electrons exist in “shells”. Each shell can facilitate only a certain number of electrons. For example, the first orbital can hold 2 electrons, the second shell and every shell after that can hold 8 electrons. This is, unfortunately, a simplified model for electron distribution once again: I may discuss more complicated models another time, if the opportunity presents itself.
Anyhoo, carbon has 6 electrons. Therefore 2 electrons exist in the first orbital, and 4 reside in the second orbital. It is energetically favourable for carbon to fill the orbital into which the last electrons are deposited and as such carbon atoms “share” electrons to make it up to the full 8, forming covalent bonds.
In an aromatic ring, carbon shares a pair of electrons with one neighbour forming a single covalent bond, while with the other neighbouring carbon it shares two pairs of electrons forming a double bond. This leaves the outer shell short of one electron (7/8) and this is sourced by sharing electrons with a hydrogen atom or another carbon.
2. A propyl chain. One of the carbons of the aromatic ring is bound via a covalent linkage to a series of 3 carbon atoms. A single bound carbon would be termed a methyl group, a two-carbon chain is termed an ethyl chain, three is propyl and four would be butyl. All carbon chains of different lengths are named weirdly. Accept it, love it. Each carbon in the chain is bound by different atoms to complete its “outer electron shell”. In the propyl chain of cathinones:
a) The first carbon forms a double bond with oxygen creating what is known as a “carbonyl group” and forms a single bond to the next carbon in the chain.
b) The second forms a single bond to nitrogen which itself is bound to 3 hydrogen atoms forming an “amine group”. This carbon also binds the last carbon in the chain.
c) The final carbon in the chain is bound by just 3 hydrogen atoms.
There you have it. The structure of cathinone. Remember, the structures of cathinone analogues are not exactly the same as previously described but it is their similarity to this basic form that allow them to elicit the same effects when ingested. How they elicit these effects shall be covered next time.