Chemistry Reference
In-Depth Information
10 Terpenes in
Human Health
10.1 THE STATIN DRUGS
In this chapter we return to some more examples of terpenes, particularly those
offering human health benefits. One important group of terpenes forms the statin
family of cholesterol-lowering drugs. Statins inhibit the enzyme hydroxymethyl-
glutaryl-CoA (HMG-CoA) reductase inhibitors known as monacolins, which play
an important role in the liver to produce cholesterol. Over the years, a great deal of
research has resulted in a number of statin compounds reaching the market, includ-
ing Mevacor, chemically known as lovastatin or monacolin K (Figure 10.1) produced
by Merck from a microbial source, and later Simvastatin originating at Bristol Myers
Squibb. The best-selling statin drug to date is sold by Pfizer and known as Lipitor.
Another source of statins is found in red yeast rice (RYR), a traditional Chinese
food and medicine, produced from fermented rice using a strain of the food fungus
Monascus purpureus Went Rice. It is sold in China as a drug and in the West as
a dietary supplement. This product has been widely used as a food supplement in
China and other Asian countries for centuries for the preparation of fish, meat, and
bean curd, and in the making of rice wine. It was used in traditional Chinese food
and medicine “to improve blood circulation and to promote a healthy digestive func-
tion in the body.” These same compounds are also found in the oyster mushroom
(Figure 10.2). In RYR, lovastatin is most often produced as the major component, but
several other related monacolin analogs are generally coproduced in fermentation.
The structures of these statin (monacolin)-related drugs are shown in Figure 10.3.
Modern methods of analysis are used to separate and identify the monacolins.
Using a reverse phase C18 (5 μm) column as a stationary phase, separation is achieved
with a linear gradient of aqueous acetonitrile and 0.1% trifluoroacetic acid (TFA) as
the mobile phase at a flow rate of 0.9 mL/min. Detection of compounds is achieved
by coupling the system either to a photodiode array (PDA) detector or, for liquid
chromatography-mass spectrometry (LC-MS) analysis, to an electrospray ionization
(ESI) quadrupole ion-trap detector.
10.2 STEROIDS AND CORTISONE
A very important and large class of naturally occurring compounds is the steroid,
represented in Figure 10.4. One example is cortisone, a 17-hydroxy-11-dehydrocorti-
costerone steroid hormone (Figure  10.5). It is used to treat a variety of ailments,
particularly to reduce inflammation, eczema, and dermatitis.
Isolation of steroids may be achieved with the use of organic solvents. Often a
saponification step is required using alcohol to rupture the steroid ester bond, releas-
ing the steroid, which can be extracted into either hexane or ether.
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