In addition to the other powers and authority prescribed by this article, the corporation may purchase debentures or the common stock of small business investment companies or minority enterprise small business investment companies, incorporated or domiciled in the state under the provisions of the Small Business Investment Law of 1958, as amended, which debentures may be subordinate to any other debenture bonds, promissory notes or other debts and obligations of such small business investment companies except for those purchased by the small business administration in accordance with the Federal Small Business Investment Act of 1958, as amended (15 USCS Sections 661 et seq.); any purchases by the corporation of stock shall be made from funds derived from sources other than the State of Mississippi. The corporation is prohibited from investing in both the stock and evidences of indebtedness of any company.