You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Pharmaceutical_industry

Context:
In 1971, Akira Endo, a Japanese biochemist working for the pharmaceutical company Sankyo, identified mevastatin (ML-236B), a molecule produced by the fungus Penicillium citrinum, as an inhibitor of HMG-CoA reductase, a critical enzyme used by the body to produce cholesterol. Animal trials showed very good inhibitory effect as in clinical trials, however a long term study in dogs found toxic effects at higher doses and as a result mevastatin was believed to be too toxic for human use. Mevastatin was never marketed, because of its adverse effects of tumors, muscle deterioration, and sometimes death in laboratory dogs.

Question:
Where did Endo discover ML-236B?

Penicillium citrinum