Exhibit 23.1



               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS



     We consent to the incorporation by reference in the Registration Statement
(Form S-3 No. 333-73890) and related Prospectus of Essential Therapeutics, Inc.
of our report dated March 16, 2001, with respect to the financial statements of
Althexis, Inc. included in this Current Report on Form 8-K/A dated October 24,
2001.

                                               /s/ ERNST & YOUNG LLP


Boston, Massachusetts
December 17, 2001