We have previously reported the discovery that antitumor activity is conferred on a monofunctional PI; on S half m~ stard,~ and on a simpler alkylating function5 by the presence of a polynuclear moiety in the same molecule. Several simple chloromethyl aromatic hydrocarbons were among the most potent compounds. This discovery was surprising since these are hydrophobic, insoluble chemicals which were given as fine ...