Pollenopyrroside A and B, Novel Pyrrole Ketohexoside Derivatives from Bee-Collected Brassica campestris Pollen

Abstract
Pollenopyrroside A and pollenopyrroside B, novel pyrrole ketohexoside derivatives, were isolated from the extract of Bee-collected Brassica campestris pollen. Their structures were elucidated by spectroscopic analysis (UV, IR, MS, NMR and X-ray) and chemical evidence. Pollenopyrrosides A and B represent a novel carbon skeleton with a six–six and five–six member dioxaspirocycle bearing nitrogen atom, respectively.