Exhibit 5


                 [HELLER EHRMAN WHITE AND MCAULIFFE LLP LETTERHEAD]


July 11, 2002



Lipid Sciences, Inc.
7068 Koll Center Parkway, Suite 401
Pleasanton, California  94566

                           POST-EFFECTIVE AMENDMENT TO
                       REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

         We have acted as counsel to Lipid Sciences, Inc., a Delaware
corporation (the "Company"), in connection with the Post Effective Amendment No.
1 (the "Amendment") to the Registration Statements on Forms S-8 (Registration
Nos. 333-88530 and 333-44017, the "Registration Statements"), which the Company
proposes to file with the Securities and Exchange Commission on or about July
11, 2002, in connection with the reincorporation of Lipid Sciences, Inc., an
Arizona corporation ("Lipid Arizona"), into the State of Delaware. The Amendment
covers shares of Common Stock of the Company (the "Shares") reserved for
issuance pursuant to the Lipid Sciences, Inc. 2001 Performance Equity Plan (the
"2001 Plan"), the Lipid Sciences, Inc. 2000 Stock Option Plan (the "2000 Plan"),
the New Mexico and Arizona Land Company 1997 Stock Incentive Plan (the "1997
Plan"), and individual Non-Qualified Stock Option Agreements with certain
consultants and a director (collectively with the 2001 Plan, the 2000 Plan and
the 1997 Plan, the "Plans"). The Company is assuming the Plans as part of the
reincorporation.

         In connection with this opinion, we have assumed the authenticity of
all records, documents and instruments submitted to us as originals, the
genuineness of all signatures, the legal capacity of natural persons and the
conformity to the originals of all records, documents and instruments submitted
to us as copies.

         In rendering our opinion, we have examined the following records,
documents and instruments:

         (a)      The Certificate of Incorporation of the Company, certified by
                  the Secretary of State of the State of Delaware as of June 19,
                  2002, and certified to us by an officer of the Company as
                  being complete and in full force as of the date of this
                  opinion;

[HELLER EHRMAN LOGO]                                        Lipid Sciences, Inc.
                                                                   July 11, 2002
                                                                          Page 2


         (b)      The Bylaws of the Company certified to us by an officer of the
                  Company as being complete and in full force and effect as of
                  the date of this opinion;

         (c)      A Certificate of officers of the Company (i) attaching records
                  certified to us as constituting all records of proceedings and
                  actions of the Board of Directors and shareholders of the
                  Company relating to the adoption of the Plans, and (ii)
                  certifying as to certain factual matters;

         (d)      A report of American Stock Transfer & Trust Company, the
                  transfer agent of the Company, as to the number of shares of
                  Common Stock outstanding as of July 8, 2002;

         (e)      The 2001 Plan;

         (f)      The 2000 Plan;

         (g)      The 1997 Plan;

         (h)      The Form of the Company's Nonqualified Stock Option Agreement
                  for Scientific Advisory Board Members;

         (i)      Nonqualified Stock Option Agreement dated as of March 25, 2000
                  between the Company and Gary S. Roubin; and

         (j)      Nonqualified Stock Option Agreement dated as of October 9,
                  2000 between the Company and Joe Markham.

         This opinion is limited to the federal laws of the United States of
America and the general corporate laws of the State of Delaware, and we disclaim
any opinion as to the laws of any other jurisdiction. We further disclaim any
opinion as to any other statute, rule, regulation, ordinance, order or other
promulgation of any other jurisdiction or any regional or local governmental
body or as to any related judicial or administrative opinion.

         Based upon the foregoing and our examination of such questions of law
as we have deemed necessary or appropriate for the purpose of this opinion, and
assuming that (i) the Shares to be sold are issued in accordance with the terms
of the applicable Plan, (ii) the full consideration stated in the applicable
Plan is paid for each Share, (iii) the per share consideration for each Share is
greater than the par value per share of the Common Stock, and (iv) all
applicable securities laws are complied with, it is our opinion that when issued
and sold by the Company, after payment therefor in the manner provided in the
applicable Plan and the Amendment, the Shares will be legally issued, fully paid
and nonassessable.

[HELLER EHRMAN LOGO]                                        Lipid Sciences, Inc.
                                                                   July 11, 2002
                                                                          Page 3


         This opinion is rendered to you in connection with the Amendment and is
solely for your benefit. This opinion may not be relied upon by you for any
other purpose, or relied upon by any other person, firm, corporation or other
entity for any purpose, without our prior written consent. We disclaim any
obligation to advise you of any change of law that occurs, or any facts of which
we may become aware, after the date of this opinion.

         We hereby consent to the filing of this opinion as an exhibit to the
Amendment.

                                    Very truly yours,


                                    /s/ Heller Ehrman White & McAuliffe LLP