The Israeli daily Haaretz published an obituary in its Hebrew edition. Below follows an English translation. [I have tried to keep it as close to the original as possible, and interpolated comments where necessary for foreign readers --- Gershom Martin]
Yehuda Mazur was born in Lodz, Poland, and immigrated to Israel with his family in 1939. After completing his studies at the Balfour high school, he 'ascended' to Jerusalem to study chemistry at the Hebrew University. He prepared his M.Sc. thesis with Prof. Moshe Weizmann, brother of The First President [of Israel, i.e. Chaim Weizmann]. During the War of Independence, he served in the Science Corps [of the nascent IDF], and afterwards traveled abroad for Ph.D. studies at the [Swiss] Federal Polytechnic in Zurich [ETH-Zuerich], under Prof. Leopold Ruzicka, Nobel Laureate in Chemistry. There he met Fanny Janko, married her, and their two sons Yair and Amos were born.
In 1954 he joined the Organic Chemistry department at the Weizmann Institute, served as Acting Department Head (1960-1962) and as Head of the Department from 1979 until his retirement in 1990. According to his student and successor, Prof. Mudi Sheves of the Organic Chemistry Department at the Weizmann Institute, "Yehuda was an excellent scientists with an international reputation, who kept alive his scientific enthusiasm to the end of his days". Indeed, over the years he published some 200 papers on his prime subjects of interest: the chemistry of steroids and their derivatives; development of physical methods for [chemical] structure determination (instead of manifold chemical reactions); development of selective molecular oxidation methods; investigations of vitamin D and its derivatives; and the use of hypericin and its derivatives as antiviral compounds. In the latter two areas, he made an important contribution to the pharmaceutical industry in Israel and abroad.
In 1979 Prof. Mazur, with Prof. Shmuel Edelstein --- then with the Biochemistry department at the Weizmann Institute --- the drug alpha-D3 of the "Teva" pharmaceutical company, which brought relief to kidney and osteoporosis patients. In its day, it was described as "The first wholly 'blue-and-white' [i.e., Israeli] drug", but part of the process was already known abroad, and thus it is [now] accepted to see copaxone --- which is used in the treatment of multiple sclerosis --- as the first drug wholly invented in Israel (again at the Weizmann Institute). In 1988, Prof. Mazur linked up with Prof. David Lavie --- likewise at the Organic Chemistry department at the Weizmann Institute --- for development of drugs based on the compound hypericin, aimed at sufferers of AIDS, brain tumors, and more. According to Dr. Gad Lavie (son of the late Prof. Lavie) of the Tel HaShomer hospital [in the Tel-Aviv suburb of Ramat-Gan], Prof. Mazur was involved, before his [final] illness, in the development of a synthetic method for commercial quantities of the compound [hypericin], aimed at clinical trials on humans.
Prof. Mazur raised generations of students, that fill key positions in academia and in industrial and defense research establishments. One of them, Dr. Amiram Hirschfeld --- presently continuing the research of Prof. Mazur with Prof. Sheves --- relates how Prof. Mazur followed his students with encouragement and warmth, and assisted them in their professional advancement: when Dr. Hirschfeld spent some time at the Criminal Identification Unit of the Israel Police [i.e., what would be called the Crime Scene Investigations unit in the US and the Forsensics department in the UK], Prof. Mazur allocated him a bench in his lab so he would develop compounds for revealing fingerprints, and later helped him find his way in the chemical industry under one of his other students. Prof. Elisha Tel-Or, of the [Hebrew University] Faculty of Agriculture in Rechovot, says that Prof. Mazur was involved all his life with compounds beneficial to human health, "in order to check whether it is possible to improve that which Nature left unfinished".