The holy grail of synthetic taxol may be in sight. Taxol, used to treat breast and ovarian cancers, is extracted in very small quantities from the leaf and bark of the endangered Himalayan and Pacific yew. But now, two teams of organic chemists -- led by K C Nicolaou of the Scripps Research Institute in California and Robert Holton of the Florida State University -- have announced that they have succeeded in synthetically isolating taxol (Science, Vol 263, No 5149).

These efforts open up possibilities of concocting "designer" taxols. Although it is a potent drug, taxol is highly insoluble and difficult to administer. Tumour cells can also develop resistance to it. Scientists now believe that by manipulating the chemical structure of taxol, they could eventually enhance its performance.