BIOSIS, accessed through Web of Science, is a citation index in the life sciences covering molecular and cell biology, pharmacology, endocrinology, genetics, neurosciences, infectious diseases, ecology and organismal biology.
Citations from approximately 4,800 worldwide journals with approximately 13 million references to journal articles in life sciences and a concentration on biomedicine. The majority of the publications covered in MEDLINE are scholarly journals from 1966 to the present.
PubChem provides information on the biological activities of small molecules. PubChem is organized as three linked databases within the NCBI's Entrez information retrieval system. These are PubChem Substance, PubChem Compound, and PubChem BioAssay. PubChem also provides a fast chemical structure similarity search tool.