25 years of Science Citation Index--some experiences.

Science Citation Index (SCI) depends for intellectual content entirely on citations by authors, who are sometimes prodded by editors and referees. Its patchiness is therefore not surprising, but frequently it gives access to relevant and up-to-date documents not easily accessible by other means. Two contrasting "citation families" are described.

N-carbamoyl-2-(p-hydroxyphenyl)glycine from leaves of broad bean (Vicia faba L.).

1. dl-2-(p-Hydroxyphenyl)glycine was resolved through the bromocamphorsulphonate to give its d-isomer. The N-carbamoyl derivatives of these amino acids were synthesized.

An obstacle in preparing alloisoleucine.

Alloisoleucine, prepared from a mixture of racemic isoleucine-alloisoleucine diastereoisomers, can be heavily contaminated with isoleucine if the recrystallization of acetyl-dl-alloisoleucine is controlled by melting point only. Two commercial specimens were found to be thus contaminated.

A search for O-polypeptidyl-ribonucleic acids in rabbit-reticulocyte ribosomes by electrophoresis in phenol-acetic acid-water systems.

1. When solutions of ;soluble' or transfer RNA (s-RNA) and of cytochrome c in phenol-acetic acid-water were mixed, intractable coacervates were formed. The addition to the solutions of various strong electrolytes prevented coacervation and allowed electrophoretic separation on filter paper.