Xantocillin

Xantocillin (INN), also known as xanthocillin X or ophthocillin, was the first reported natural product found to contain the isocyanide functional group. It was first isolated from Penicillium notatum by Westling in 1950 and subsequently from several other sources. ...
Found on http://en.wikipedia.org/wiki/Xantocillin
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