ARYX ARYx Therapeutics Inc (CE)

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I — REGISTRANT INFORMATION

PART II — RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

PART III — NARRATIVE

State below in reasonable detail why Forms 10 - K, 20 - F, 11 - K, 10 - Q, 10 - D, N - SAR, N - CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

As previously disclosed, following preliminary notification from the U.S. Food and Drug Administration, or the FDA, of an additional delay by the FDA in providing guidance regarding the special protocol assessment we submitted for our lead product candidate naronapride, we were advised by our existing principal and potential new investors that were contemplating a potential

financing arrangement for our company  that they would not be participating in any future funding of our company.  In addition, as previously disclosed, we received a notice of default, or the Notice, from one of our secured lenders, Lighthouse Capital Partners V, L.P., or Lighthouse, on March 16, 2011, indicating an event of default had occurred under that certain Loan and Security Agreement No. 4512, dated as of March 28, 2005, as amended, by and between Lighthouse and us.  The Notice demands we turn over the collateral securing our loan with Lighthouse, which consists of all of our assets, including our intellectual property.

Our Board of Directors has determined that continued operations of our company is not possible due to our lack of cash resources and no available funding options, and has authorized our management to cooperate with our secured creditors to effect an orderly wind-down of our operations, which is currently in process.  Absent the continued cooperation and agreement of our secured creditors to effect an orderly wind-down of our operations and disposition of our assets, our Board of Directors has authorized and directed management to proceed with the filing by us of a voluntary petition for bankruptcy under the provisions of Chapter 7 of the U.S. Bankruptcy Code.

In light of the foregoing developments, our independent registered public accounting firm will not be providing us with audit or other services going forward and will not be in a position to issue a report and consent in connection with an Annual Report on Form 10-K for the year ended December 31, 2010.  Accordingly, we lack the resources and personnel to continue to fulfill any reporting obligations under Section 13(a) of the Securities and Exchange Act of 1934, as amended.

(Attach extra Sheets if Needed)

PART IV — OTHER INFORMATION

ARYx Therapeutics, Inc.

(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

INSTRUCTION: The form may be signed by an executive officer of the registrant or by any other duly authorized representative. The name and title of the person signing the form shall be typed or printed beneath the signature. If the statement is signed on behalf of the registrant by an authorized representative (other than an executive officer), evidence of the representative’s authority to sign on behalf of the registrant shall be filed with the form.