A study of tobacco carcinogenesis.XI. Tumor initiators, tumor accelerators, and tumor promoting activity of condensate fractions

Abstract

The neutral portion of cigarette smoke condensate, its fraction B, and subtraction BI are the only portions of cigarette smoke condensate which are active as carcinogens and tumor initiators. BI amounts to about 0.6% of dry “tar” and contains polynuclear aromatic hydrocarbons (PAH), N- and O-heteroaromatic compounds, chlorinated insecticides, and some of their pyrolysis products, esters, terpenes, and quinones. Heretofore, 12 known carcinogens and several tumor accelerators have been identified. BI was separated into 5 portions. The active portion (BIh, 0.09%) was chromatographed into 80 subtractions. BIh 56-66 were highly active as tumor initiators, but did not contain known carcinogens; BIh 71-78 contained known as well as unidentified carcinogens. Such alkylated PAH, as alkylated fluoranthenes, cyclopentaphenanthrenes, and chrysenes, are present in significant concentration in the active BIh sub-fractions. Of all tobacco “tar” fractions, only the acidic portion showed significant tumor promoting activity.