Issue Date: July 18, 2016
Juno, Tamiflu, and Theranos
A couple of stories caught my attention over the past couple of weeks.
The first one is the arrival of Juno in Jupiter. Juno is a NASA space probe that was launched in August 2011 and entered the orbit of Jupiter this month. The spacecraft is the ninth to visit Jupiter and only the second to stay in the planet’s orbit. It’ll now spend 20 months studying the planet and beaming information back to Earth, including data about the composition of Jupiter’s atmosphere and the nature of the planet’s core (see page 25).
Second, researchers at Tohoku University have reported the 60-minute total synthesis of oseltamivir, an antiviral drug marketed as Tamiflu (Org. Lett. 2016, DOI: 10.1021/acs.orglett.6b01595). The neuraminidase inhibitor is used to treat—and in some cases prevent—flu caused by influenza A and B. The authors of the study reported one-pot chemistry that takes just five steps to complete in less than one hour. This is in contrast with previous one-pot procedures that take 57 hours for completion of all synthetic transformations. It also differs from other multistep reaction mechanisms, which take a minimum of 30 hours to complete. Commercial manufacture of Tamiflu is a complex process that uses shikimic acid—a substance that can be extracted from star anise or produced by bacterial fermentation—as starting material.
The Tohoku team’s new synthesis starts with a nitroalkene that undergoes a Michael reaction in the presence of three catalysts. This is followed by domino Michael and Horner-Wadsworth-Emmons reactions and protonation with HCl. Epimerization from the undesired 5R isomer to 5S is the next step followed by a reduction of a nitro group to an amine using zinc and microwave radiation. Reduction took a mere five minutes to complete.
The reaction proved effective not only in terms of reducing reaction time but also in terms of yield, selectivity, and greenness.
Of course this 60-minute synthesis of oseltamivir is nothing compared with the three-minute synthesis of ibuprofenusing continuous-flow technology reported in 2014 (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201409093). But it is a move in the right direction: Both processes allow the production of common medicines in record time, cheaply, simply, and effectively. As a result, they could eliminate or reduce the need to stockpile reserves because drugs can be produced at very short notice. The ability to achieve these reduced production times in drugs such as Tamiflu or certain vaccines would transform the way countries around the world prepare for and respond to emergency situations such as outbreaks or pandemics.
And finally, the Theranos saga that I have been covering in these pages over the past few months saw yet another installment. As you know, Theranos is the blood-testing firm founded by Elizabeth Holmes. The company had received a lot of scrutiny from the media, which intensified last year when a Wall Street Journal exposé revealed that Theranos was under investigation by regulators. Now regulators have revoked Theranos’s license to operate its California lab and banned Holmes from the blood-testing business for at least two years. Theranos also faces criminal probes by the Securities & Exchange Commission and the Department of Justice about whether it misled investors and regulators about its technology and operations as well as eight consumer lawsuits.
Theranos is said to be cooperating with agencies and regulators and undertaking “remedial action” at its California lab. But with the announcement of Holmes’s ban and so many questions yet to be answered about the technology, the valuation of the company dropped from $9 billion to $800 million. Interestingly, Holmes is still scheduled to present data on Theranos’s blood-testing devices on Aug. 1 at the American Association for Clinical Chemistry conference in Philadelphia. Will she turn up? Many of us are looking forward to her presentation.
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