Cupiennins are a group of small cytolytic peptides from the venom of the wandering spider Cupiennius salei. They are known to have high bactericidal, insecticidal and haemolytic activities. They are chemically cationic α-helical peptides.[1] They were isolated and identified in 2002 as a family of peptides called cupiennin 1. The sequence was determined by a process called Edman degradation, and the family consists of cupiennin 1a, cupiennin 1b, cupiennin 1c, and cupiennin 1d. The amino acid sequences of cupiennin 1b, c, and d were obtained by a combination of sequence analysis and mass spectrometric measurements of comparative tryptic peptide mapping. Even though they are not strong toxins, they do enhance the effect of the spider venom by synergistically enhancing other components of the venom, such CSTX.[2]