Clausenain B, a phenylalanine-rich cyclic octapeptide from Clausena anisum-olens

a new cyclic octapeptide, named clausenain b, was isolated by a multi-step chromatography procedure from clausena anisum-olens. its structure was established as cyclo(-phe1-ser-leu1-phe2-phe4-gly-leu2-phe3-) (1) based on extensive spectroscopic studies and chemical evidence. clausenain b (1) is a phenylalanine-rich cyclic octapeptide.