Ala. Code § 37-7-14

In connection with the issuance of any obligations, a corporation may make such covenants or agreements and do any and all such acts and things as may be necessary or convenient or desirable in order to secure its obligations or which, in the absolute discretion of the board, tend to make the obligations more marketable, notwithstanding that such covenants, agreements, acts and things may constitute a limitation on the exercise of the powers granted in this chapter.