Technical Update:

The Commercial Chemistry of GHB

The consequences of Schedule-I status for GHB and its analogs will be far reaching due to widespread industrial and commercial uses of these chemicals. The Schedule-I prohibition is absolute, meaning that “any detectable amount” is sufficient to make a commodity or retail product illegal. The presence of GHB and its analogs in foods is only the tip of the GHB-iceberg. GHB and its analogs are used to make a wide variety of polymer products (plastics, resins, fibers, films, elastics, coatings, etc.).

When GHB molecules are strung together like beads on a string (or like amino acids in a protein or enzyme), the resulting molecule is one kind of polyester. The word “ester” refers to a kind of chemical bond formed when an alcohol links with an acid.

One of the simplest esters is ethyl acetate, which is formed by bonding ethanol (ethyl alcohol) to acetate (acetic acid, vinegar) (see Figure A, top illustration [not shown]). Ethyl acetate is a volatile solvent that is used in some acetone-free nail-polish removers.

Unlike alcohol and acetate, GHB has both alcohol and acid groups on the same molecule. This dual capability means that GHB can form ester bonds with itself, or with other GHB molecules. When a GHB molecule forms an ester bond with itself, it becomes an “internal” or “cyclic” ester, which is called a lactone).So gamma-butyrolactone (GBL) is the cyclic ester of GHB. GBL is like a GHB-snake biting its own tail.

When a GHB molecule forms ester bonds with other GHB molecules, they attach on an alcohol-to-acid or acid-to-alcohol basis, much like a tangle of snakes randomly biting the tails of other snakes.

When the chain grows long, it is called a “polyester” (poly meaning many, ester meaning the alcohol-acid bond). A polyester is a long molecule with lots of ester linkages in it. Poly-GHB is but one example of a polyester.

The formation of the ester bond from an alcohol and an acid releases a molecule of water (see Figure A {not shown]). This is exactly analogous to the reaction between an amine and an acid to form an amide. The amide bond is similar to the ester bond, except that it contains nitrogen (N) from an amine, rather than oxygen (O) from an alcohol (see Figure A). The amide equivalent of poly-GHB is poly-GABA, otherwise known as Nylon-4. Amide polymers are extremely important in biology — we call them proteins. Amide bonds serve as the linkages between amino acids when they are assembled into enzymes, proteins and peptides (small proteins). Amino acids also release water when they are assembled into proteins (see Figure A).

When chemical engineers want to avoid water in their polyester or polyamide plastics, they resort to using the cyclic “dehydrated” version of GHB or GABA. The cyclic version of GHB is GBL, which has already been mentioned. The cyclic version of GABA is gamma-butyrolactam. A lactam is the nitrogen analog of a lactone. With an appropriate catalyst to start the reaction, these cyclic lactones and lactams reassemble into long polymer chains without generating water. Although GHB-derived and GBL-derived polymer chains have the same basic chemical structures—as do GABA-derived and butyrolactam-derived polymers—the presence or absence of water does alter the mechanical properties of these polymers. However they may be made, the polymer subunits (GHB or GABA) are still identifiable within the larger structure (see Figure B). In fact, these larger polymer chains break down into their molecular subunits when they are exposed to water, extreme pH, powerful solvents, elevated temperatures and/or high pressures. Some polymers are more resistant to hydrolysis (water breakdown) than others.

It is the ready reversibility of polyamides that makes them so valuable biologically. Proteins (polyamide polymers) can be disassembled (enzymatically digested) into monomer (amino acids) which can then be reassembled (recycled) into new proteins. This process is efficient.

Not all polymers have this readily reversible nature. Polymers made from carbon-carbon double bonds (polyethylene, poly-propylene, polyvinyls and polystyrenes, for example) do not reverse in the presence of water.

To be complete, I should point out that not all polyesters are made from GHB. Polyesters can also be made from succinic acid and 1,4-butanediol (i.e., gamma-hydroxybutanol) (see Figure B). Succinic acid is like a GHB molecule with two acids at each end (i.e., a two-headed snake), and 1,4-butanediol (butylene glycol) is like a GHB molecule with two alcohols at each end (i.e., a two-tailed snake). They bond to form polyester polymers in a nearly identical manner (i.e., snake heads still bite snake tails), but there ends up being a difference in the orientation of the ester bonds (see left- vs right-facing snake heads in margin illustration on previous page). Many polyesters are made in this two-part manner.

There are many different ways this polyester “recipe” can be modified. If succinic acid is replaced with phthalic or terephthalic acids (an aromatic ring with acids at two sides) or adipic acid (a two-carbon longer version of succinic acid), you get different varieties of polyesters. If 1,4-butanediol is replaced with 1,6-hexanediol or 1,2-ethanediol (ethylene glycol), you get still other kinds of polyesters. When carbonate is used to link diols (di-alcohols, e.g., 1,4-butanediol), you get polycarbonate plastics (commonly used in water bottles). The carbonate group is like a two-sided ester (see Figure C [not shown]). Carbonate and ester linkages can be intermixed in the same polymer.

Many different plastics use GHB or GHB- like molecules as part of their structures. For example, 1,4-butanediol is used in making polyurethane elastomers (i.e., Spandex), polyvinylpyrrolidones (used in PVP-iodine, toothpastes, blood-plasma extenders, textile finishes, adhesives, cosmetics, beer and wine clarifiers), and alkyd resins (used in marine and exterior house paints, and in electrical components such as distributor caps). The full presence and extent of GHB analogs in commercial products is far beyond my knowledge, which is far beyond that of the average citizen. Nevertheless, the law and the courts hold that “ignorance of the law is no excuse.”

The inherent hypocrisy of that position may be best exemplified by law-enforcement agents, who are charged with the enforcement of the controlled-substance statutes, yet who rely upon GHB-analog polymers in their bullet-proof vests, stronger-than-steel automotive parts and high-performance polymer-reinforced tires for the safe performance of their duties.

Then again, perhaps the greatest irony is that politicians have criminalized their own “innocent” behaviors and thereby opened themselves to the possibility of being placed under citizen’s arrest while publically dining on GHB-containing steaks or buying GHB-containing groceries at a supermarket. This adds a whole new twist to the concept of civil disobedience.