Tetrahydrogestrinone THG

Figure 1.1 Pharmacologist Dr. Donald H. Gatlin sits in front of an LC/MS/MS system, an instrument used for detecting drugs from urine samples, at the UCLA Olympic Analytical Laboratory. Gatlin is noted for developing a breakthrough testthat detects the illegal steroid, tetrahydrogestrinone (THG), taken by athletes to enhance performance.

This general approach is not permanent, but each time the laboratories improve the efficacy of the detection procedure, cheaters immediately turn into any possible remaining loopholes. As a recent example, tetrahydrogestrinone (THG), a new designer steroid produced specifically for the exclusive purpose to improve athletic performances, posed a real identification challenge to the laboratories. The development or the implementation of rapid, informative, and reliable systematic screening tests, which have the required sensitivity and can withstand the scrutiny of cross-examination at the Court, is constantly needed. 

Steroids have had a major beneficial effect on human well-being, as medicines and in the control of fertility. However, abuse of steroids as performance-enhancing drugs in competitive athletics has surfaced occasionally. Thus, the sports world was shaken when illicit use of the designer steroid tetrahydrogestrinone (THG) was discovered in 2003— designed to avoid detection in doping tests. 

You will have noticed the presence of the C=C triple bond attached to C17 in these synthetic compounds, an alteration that makes the drugs particularly potent. Such triple bonds can be hydrogenated ( saturated ) with hydrogen in the presence of a catalyst (Section 13-6). It is suspected that it was this simple alteration of the commercial drug gestrinone that led to the dopant tetrahydrogestrinone (THG see Chapter Opening). 

Figure 4.5 Structures of selected steroidal analytes 5a-androstan-17P-ol-3-one (1), 5P-androstan-17P-ol-3-one (2), 17a-methyl-5a-androstan-17P-ol-3-one (3), la-methyl-5a-androstan-17P-ol-3-one (4), testosterone (5), nandrolone (6), 1-testosterone (7), metenolone (8), 5a-androst-l-ene-3,17-dione (9), metandienone (10), 18-nor-17P-hydroxymethyl,17a-methyl-androst-l,4,13-trien-3-one (metandienone metabolite) (11), androsta-4,6-dien-17P-ol-3-one (12), androsta-4,9-dien-17P-ol-3-one (13), trenbo-lone (14), methyltrienolone (15), tetrahydrogestrinone (THG, 16), and stanozolol (17).

Anabolic steroids, such as stanozolol, nandrolone, and tetrahydrogestrinone have the same effect on the body as testosterone, but they are more stable, so they are not metabolized as quickly. Tetrahydrogestrinone (also called THG or The Clear), the performance-enhancing drug used by track star Marion Jones during the 2000 Sydney Olympics, was considered a designer steroid because it was initially undetected in urine tests for doping. After its chemical structure and properties were determined, it was added to the list of banned anabolic steroids in 2004. 

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