What is "hopanoids"

n. (plural of hopanoid English)

Hopanoids are natural pentacyclic compounds (containing five rings) based on the chemical structure of hopane. The first known triterpenoid of the class, hydroxyhopanone, was isolated by two chemists at The National Gallery, London working on the chemistry of dammar gum, a natural resin used as a varnish for paintings. The name hopane was derived from the genus Hopea (a source of the resin) itself named after John Hope, the botanist. Since this first finding, however, hopanoids have been found to be present in nature in vast amounts as components of bacteria and other primitive organisms. A range of hopanoids are found in petroleum reservoirs, where they are used as biological markers. Hopanoids are not detected in archaea.