AMENDMENT TO LEASE AGREEMENT
DATED DECEMBER 23, 1996
BY AND BETWEEN
DOUGLAS KAYE, LESSOR
AND
GLYKO, INC., LESSEE
DATED MARCH 15, 2000


The above referenced lease agreement shall be amended as follows:

RENT
Commencing  April 1, 2000  section  1,  "Rent" of the lease  agreement  shall be
amended as follows:
Year 1: $12,100 per month
Year 2: $12,700 per month
Year 3: $13,300 per month

OPTION TO RENEW
In the  event  Lessee  has not  been  in  default  under  any of the  terms  and
conditions  of this lease  Lessee  shall have two (2),  two (2) year  options to
renew upon the following term and  conditions:  Lessee shall give Lessor written
notice of Lessee's intent to exercise its option to renew no earlier than twelve
(12) months and no later than six (6) months prior to the lease expiration date,
and first option to renew period, if exercised.

First Option Period
Year 4: $13,850 per month
Year 5: $14,500 per month

Second Option Period, if exercised
Rent for the second option period shall be determined as follows:

Rent shall be adjusted to the then fair market value for the Premises (the "Fair
Market  Value").  Fair Market Value is defined as the rent for Comparable  Space
(office and R&D), in new leases signed  directly  with the  respective  lessors,
within the  previous  six (6) months of the  exercise  of any given  option (the
"Comparable  Leases").  If there  have been no leases  signed  within  such time
period,  then  Fair  Market  Value  shall  be  defined  as the rent  quoted  for
Comparable Space (the "Quoted Rent").  The definition of Fair Market Value shall
include annual rent  adjustments in the Comparable  Leases or Quoted Rent. In no
event shall the rent for any option  period be less than the rent paid by Lessee
during the year immediately preceding such option period.

All other  terms and  conditions  of the lease  shall  remain the same unless as
indicated herein.

Lessee: Glyko, Inc.                          Lessor: Douglas Kaye

By: /s/ Raymond Anderson                     By: /s/ Douglas Kaye

Title: Vice President Finance and Admin.     Title:

Date:  March 17, 2000                        Date:  March 22, 2000