Isolation of guaianoid pigments from the gorgonian Calicogorgia granulosa.

Three pigments of the guaiazulene class have been isolated from the gorgonian Calicogorgia granulosa. Structures of these compounds have been determined as guaiazulene, 2,2'- diguaiazulenylmethane, and a new compound, 2,2'-biguaiazulenyl, by combined chemical and spectroscopic methods. 2,2'-Biguaiazulenyl exhibited moderate antimicrobial activity.