Ephedra bases

Figure 4.2 Steve Bechler, a former pitcher for the Baltimore Orioles, died after taking a weight loss supplement containing ephedra. Here he is being taken off the playing field during training camp, when he began to suffer from heat exhaustion, a side effect of ephedra-based drugs.

Even before the FDA s official ban, many supplement companies volunteered to pull their own ephedra-based products from shelves. They also scrambled to come up with a similar ingredient after news of Bechler s death. Newer, ephedra-free supplements contain HCA, bitter orange, or other so-called thermogenic substances, often combined with each other. 

Enamide cyclizations, application in alkaloid synthesis, 22, 189 (1983) Enzymatic transformation of alkaloids, microbial and in vitro, 18, 323 (1981) Ephedra bases, 3, 339 (1933)... 

A disulfide-linked bis(aminoethanol) 82 prepared from L-cystine also catalyzes the borane reduction of ketones. Other oxazaborolidine derivatives are obtained from 83, 84, " and 85, " and polymer-bound species. Those derived from the ephedra bases find use in the asymmetric reduction of imines. bicyclic oxazaborolidine generated... 

In the only large study ever done to assess risk factors for stroke in young people (age 20-49) over a 1 -yr period (in Poland, a country where ephedra based products are widely used), nearly half the stroke cases were associated with preexisting hypertension, another 15% had hyperlipidemia, and 6% were diabetic (Jovanovic, 1996). None of the individuals were ephedrine users. 

Several bases, other than ephedrine and i -ephedrine, have been identified in Ma Huang. Smith found 1-iV-methylephedrine (146) and nor-d-i -ephedrine (147) in the sirupy alkaloidal residue obtained in the manufacture of ephedrine. Nagai and Kanao (149), working up thoroughly a Ma Huang extract, confirmed Smith s observations and separated another new alkaloid, d-A-methyl- f -ephedrine. Kanao (150) succeeded in isolating a sixth ephedra base, 1-norephedrine. 

The separation of the six natural ephedra bases has been described by Kanao (150). /-Ephedrine was first separated as hydrochloride, then -ephedrine as the free base, /-methylephedrine as the oxalate, d-methyl-lA-ephedrine as the d-bitartrate and finally nor-d- -ephedrine, from... 

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