Barend Coenraad Petrus Jansen

B. C. P. Jansen (1 April 1884, Zwolle - 18 October 1962) was a Dutch chemist and biochemist. In the Dutch Indies, with his colleague W. F. Donath, he isolated in crystalline form an anti-beriberi factor (known as vitamine B1 or aneurin) from rice polishings and named it thiamine (sulfur-containing amine). It was the first vitamine to be obtained in pure form.