Note 10 - Common stock warrants

On August 21, 1998, the Company filed for voluntary reorganization with the United States Bankruptcy Court for the Northern District of California, and on January 11, 2000, the Company’s Plan of Reorganization was approved. Among other things, the Company’s Plan of Reorganization allowed creditors and claimants to receive new Series A, B, C, and D warrants in settlement of their prior claims. All Series A and Series C warrants were exercised by December 31, 2014. All Series B warrants were exercised on January 11, 2022. Exercise prices in effect from January 1, 2015 through December 31, 2022 for Series D warrants were $1.60. On October 14, 2023, the Board of Directors of the Company authorized a reset of the Series D warrants strike price to $0.02 plus a $0.10 per warrant redemption fee, if applicable.

The Company intends to allow warrant holders or Company designees, in place of original holders, additional time as needed to exercise the remaining Series D warrants.

As of March 31, 2026, and December 31, 2025, there were 4,250,000 Series D warrants outstanding with an exercise price of $0.02 per share plus a $0.10 per warrant redemption fee, if applicable. If the called warrants are not exercised, the Company has the right to designate the warrants to a new holder in return for a $0.10 per share redemption fee payable to the original warrant holders. All such changes in the exercise price of warrants were provided for by the court in the Plan of Reorganization to provide a mechanism for all debtors to receive value even if they could not or did not exercise their warrants. The Series D warrants expire on May 11, 2038.

In 2009, the Company entered into an Investment Banking Agreement and a related Strategic Advisory Agreement regarding a potential merger with a cancer development company. In conjunction with those related agreements, the Company issued 689,159 Series H ($7) Warrants with a 30-year life. As of March 31, 2026, and December 31, 2025, there were 413,512 Series H ($7) warrants outstanding. The warrants are subject to cashless exercise based upon the ten-day trailing closing bid price preceding the exercise as interpreted by the Company. The Series H warrants expire on November 8, 2039.

As of March 31, 2026, and December 31, 2025, the weighted average contractual life for all Mentor warrants was 12.25 years and 13.25 years, respectively, and the weighted average outstanding warrant exercise price was $0.64 and $0.62 per share, respectively.

During the three months ended March 31, 2026, no Series D warrants were exercised, and no warrants were issued. The intrinsic value of outstanding warrants at March 31, 2026 and December 31, 2025 was $110,500 and $237,150, respectively.

The following table summarizes Series D common stock warrants as of each period:

 Schedule of common stock warrants 

Series E, F, G, and H warrants were issued for investment banking and advisory services during 2009. Series E, F, and G warrants were exercised in 2014. As of March 31, 2026, there were 413,512 Series H ($7) Warrants outstanding. The following table summarizes Series H ($7) warrants as of each period:

On February 9, 2015, in accordance with Section 1145 of the United States Bankruptcy Code and the Company’s Third Amended Plan of Reorganization, the Company announced a minimum 30-day partial redemption of up to 1% of the already outstanding Series D warrants to provide for the court specified redemption mechanism for warrants not exercised timely by the original holder or their estates. Company designees that applied during the 30 days paid 10 cents per warrant to redeem the warrant and then exercised the Series D warrant to purchase a share of the Company’s Common Stock at the court-specified formula of not more than one-half of the closing bid price on the day preceding the 30-day exercise period. In successive months, the authorized partial warrant redemption amount was recalculated, and the redemption offer repeated according to the court formula. In the Company’s October 7, 2016 press release, Mentor stated that the 1% redemptions which were formerly priced on a calendar month schedule would subsequently be initiated and priced on a random date schedule after the prior 1% redemption was completed to prevent potential third-party manipulation of share prices at month-end. The periodic partial redemptions could continue to be recalculated and repeated until such unexercised warrants are exhausted, or the partial redemption is otherwise paused, or truncated by the Company. For the three months ended March 31, 2026, and 2025 no warrants were redeemed.