Abstract: This invention provides a compound of the structure ##STR1## wherein R.sup.1 and R.sup.2 are each, independently, hydrogen or ##STR2## R.sup.3 is --(CH.sub.2).sub.q CO.sub.2 R.sup.6 ;R.sup.4 is hydrogen, alkyl, or arylalkyl;R.sup.5 is hydrogen or COOR.sup.7 ;R.sup.6 is hydrogen, alkyl, alkenyl, arylalkyl, fluorenylmethyl, or phenyl which is optionally substituted;R.sup.7 is alkyl, alkenyl, arylalkyl, fluorenylmethyl, or phenyl which is optionally substituted;m is 0-4;n is 0-4;p is 1-2;q is 0-4;wherein R.sup.3, R.sup.4, m, and n are independent in each of the ##STR3## subunits when p=2; with the proviso that R.sup.1 and R.sup.2 are not both hydrogen; and further provided that if R.sup.5 is CO.sub.2 R.sup.7, then R.sup.6 is hydrogen; and still further provided that if R.sup.6 is not hydrogen, then R.sup.5 is hydrogen;or a pharmaceutically acceptable salt thereof which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent.