December 3, 1999

by Glycogenesys Inc
April 28th, 2000

December 3, 1999

Jon Arnold
Shaw's Supermarkets
140 Laurel St.
E. Bridgewater, MA 02333

Dear Jon:

As we discussed, the following will serve to formalize our agreement with regard
to exclusivity for Shaw's. Please review and initial at the bottom of the page
if you are in agreement.

1.    The definition of exclusivity will consist of two components: (1) Any
      product brought to market by SafeScience, Inc. and (2). The brand name
      "SafeScience".

2.    Shaw's will have supermarket channel exclusivity throughout New England
      for as long as they stock these lines. New England will be defined as the
      states of Maine, New Hampshire, Vermont, Massachusetts, Connecticut and
      Rhode Island. This exclusivity will pertain to all supermarket retailers
      doing business in New England, including retailers whose base is outside
      New England but have stores which spill-in to the region. (Except that
      SafeScience will have the right to sell to supermarkets whose base is
      outside New England if they agree not to place the products into their New
      England stores).

3.    Shaw's may grant an exception to supermarket channel exclusivity,
      especially for retailers with minimal numbers of stores in the region.
      SafeScience must make a written request for all exceptions and provide
      store locations to Shaw's. However, Shaw's is not obligated to grant any
      such requests for exclusivity.

4.    Shaw's will have a six-month exclusivity for all retail channels, for the
      six months September 1, 1999 to February 28, 2000. This would exclude all
      existing distribution such as CVS, BJ's Wholesale Club and small
      hardware/home center outlets.

5.    Exclusivity is not transferable to other markets, should Sainsbury
      purchase additional retailers.

6.    Shaw's will have the right of first refusal on any new SafeScience
      products. If Shaw's does not exercise this right within 90 days,
      SafeScience has the right to market this technology to any New England




      supermarkets but cannot use the SafeScience brand name as the brand.

SafeScience:           /s/ Richard Salter                           Date:3/3/00
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Shaw's:      /s/ Illegible                                          Date:12/3/99
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