Navigation Links
They were right after all
Date:1/31/2008

This release is also available in German.

Drugs derived from cinchona bark, known as cinchona alkaloids, have been used in healing from ancient times. The most prominent representative of this group is quinine, a bitter substance contained in beverages such as tonic water and used in modern medicine to combat malaria. As early as 1945, Robert Burns Woodward and William von Eggers Doering (Harvard University) described how to synthesize quinine in the laboratory. The last step of this formal total synthesis, a three-step reaction procedure previously described by Paul Rabe and Karl Kindler in 1918, has continued to be the subject of much controversy to this day. Aaron C. Smith and Robert M. Williams at Colorado State University (USA) have now successfully reproduced the RabeKindler protocol. As described in an Angewandte Chemie article dedicated to Doering on his 90th birthday, they repeated the entire procedure without employing any modern methods.

Had they done it or not? That has been the question for decades. Woodward and Doering published the synthesis of d-quinotoxine in 1944. Based on the conversion of d-quinotoxine into quinine described by Rabe and Kindler in 1918, they claimed to have derived the total synthesis of quinine, though they had not actually completed this last step themselves before publishing. Their formal total synthesis was strongly challenged and was even dismissed as a myth by Gilbert Stork (Columbia University) in 2001.

Quinine and the cinchona bark alkaloids play an important role in modern medicine. It is thus amazing that no attempts to reproduce the RabeKindler conversion of quinotoxine into quinine have been published, marvels Williams. Smith and Williams reviewed the old publications, researched further references, and set themselves the task of repeating the procedure outlined by Rabe and Kindlerand with techniques available at the time. Initially, the yield of quinine they obtained was far too low. The key turned out to be the aluminum powder used as a reducing agent in the last step. It must not be too fresh, instead it must be exposed to air for a while first to produce a small amount of aluminum oxide. This results in yields of quinine in agreement with those in the old publications.

Analytically pure quinine can be isolated from this reaction by the selective crystallization of the corresponding tartrate salt, just as described by Rabe in 1939, says Williams. We have thus corroborated Rabe and Kindlers 1918 publication. Woodward and Doering could theoretically also have followed this procedure in 1944.


'/>"/>

Contact: Robert M. Williams
rmw@chem.colostate.edu
970-491-6747
Wiley-Blackwell
Source:Eurekalert

Related medicine news :

1. Bright Options for Medicare Beneficiaries in Louisiana
2. A Bright Future for Medicare Beneficiaries in Maine
3. KV Pharmaceutical Company Announces Acquisition of Rights to Gestiva(TM)
4. Phony Physicians Committee Suing Restaurants is Animal-Rights Trojan Horse, says CCF
5. Wachovia Foundation Announces $1 Million Each for Atlanta BeltLine Partnership, Center for Civil and Human Rights
6. Brighton Hospital Announces Creation of Brighton National Addiction Foundation
7. Exercise Your Right to Vote and Continue to Make a Difference by Giving Blood in 2008
8. AARP Calls New EEOC Policy A Civil Rights and Economic Fiasco
9. Make 2008 the Year to Find an Insurance Agent Thats Right for You
10. Settlement Reached Between Dilon Technologies and Naviscan on Patent Rights
11. AAPD to Present 2008 Henry B. Betts Award to International Human Rights Disability Advocate Eric Rosenthal
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, ... Christina Austin - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms ... Final Cut Pro X . Simply select a ProHand generator and drag it above ...
(Date:6/25/2016)... ... 2016 , ... As a lifelong Southern Californian, Dr. Omkar Marathe earned his ... David Geffen School of Medicine at UCLA. He trained in Internal Medicine at Scripps ... in hematology/oncology at the UCLA-Olive View-Cedars Sinai program where he had the opportunity to ...
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, Van ... Wellness at Work award to iHire in recognition of their exemplary accomplishments in worksite ... 7th annual Maryland Workplace Health & Wellness Symposium at the BWI Marriott in Linthicum ...
(Date:6/24/2016)... Angeles, CA (PRWEB) , ... June 24, 2016 , ... ... surgery procedures that most people are unfamiliar with. The article goes on to state ... procedures, but also many of these less common operations such as calf and cheek ...
(Date:6/24/2016)... ... June 24, 2016 , ... June 19, 2016 is World Sickle ... chronic pain and the benefits of holistic treatments, Serenity Recovery Center of ... Sickle Cell Disease. , Sickle Cell Disease (SCD) is a disorder of the red ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... 24, 2016  Consumers have taken a more ... placed more emphasis on patient outcomes. ... in the pharmaceutical industry have evolved beyond just ... companies are focusing on becoming more patient-oriented across ... and services that improve health. ...
(Date:6/24/2016)... , June 24, 2016 ... of the "Structural Electronics 2015-2025: Applications, Technologies, ... In-Mold Electronics, Smart Skin, ... Photovoltaics Structural electronics involves electronic ... load-bearing, protective structures, replacing dumb structures such as ...
(Date:6/24/2016)... -- According to a new market research ... Safety Pen Needles), Needle Length (4mm, 5mm, 6mm, 8mm, ... Purchase (Retail, Non-Retail) - Trends & Global Forecasts to ... for the forecast period of 2016 to 2021. This ... 2021 from USD 1.65 Billion in 2016, growing at ...
Breaking Medicine Technology: