7.   Promissory Note Receivable

On June 19, 2023, the Company was issued a promissory note (the “Note”) with Safi Biosolutions, Inc. (“Safi”) in the principal amount of $1,500,000, which was issued in exchange for the convertible promissory note (the “Convertible Note”) issued to the Company by Safi on October 1, 2020. The Note has a maturity date of two (2) years from the date of issuance and can be extended by the mutual consent of the Company and Safi for two (2) additional one (1) year terms upon the payment of all accrued interest accrued through the date of such extension. In addition, the outstanding balance under the Note, or portions thereof, is due within a specified number of days after the receipt by Safi in a closing of specified financing milestones as more detailed in the Note. The Note bears interest at the rate of 5% per annum, which will increase to 7% for the first one (1) year extension and 9% for the second one (1) year extension. Upon the issuance of the Note, the Convertible Note, which bore interest at the rate of 5% per annum and had a maturity date of October 1, 2023, was voided.

​

For the three months ended March 31, 2024 and 2023, interest income amounted to $22,000 and $18,000, respectively. For the nine months ended March 31, 2024 and 2023, interest income amounted to $66,000 and $56,000, respectively. As of March 31, 2024 and June 30, 2023, the Note balance and accrued interest, which have been classified as long term, totaled $1,772,000 and $1,687,000, respectively.