A compound of the structure ##STR1## wherein R.sup.1 and R.sup.2 are each, independently, hydrogen, --CONR.sup.3 (CR.sup.4 R.sup.5).sub.m (CR.sup.6 R.sup.7).sub.n (CR.sup.8 R.sup.9).sub.p NR.sup.10 R.sup.11, or ##STR2## or --CONR.sup.3 R.sup.13 ; R.sup.3 is hydrogen, alkyl, or arylalkyl;R.sup.4, R.sup.5, R.sup.8, and R.sup.9 are each, independently, hydrogen, alkyl, --OH, --CF.sub.3, or --F;R.sup.6 is hydrogen or --OR.sup.13 ;R.sup.7 is hydrogen or alkyl;R.sup.10 is hydrogen, alkyl, or arylalkyl;R.sup.11, R.sup.12 and R.sup.13 are each, independently, --(CR.sup.15 R.sup.16).sub.r R.sup.17 ;R.sup.14 is hydrogen, alkyl of 1-6 carbon atoms, tri-(alkyl)silyl, tri-(alkyl)silylethyl, triphenylmethyl, benzyl, alkoxymethyl, tri-(alkyl)silylethoxymethyl, or tetrahydropyranyl;R.sup.15 and R.sup.16 are each, independently, hydrogen or alkyl;R.sup.17 is ##STR3## or --C.tbd.C--R.sup.21 ; R.sup.18, R.sup.19, R.sup.20, and R.sup.21 are each, independently, hydrogen, alkyl, halogen, or phenyl, wherein the phenyl group may be optionally mono-, di-, or tri-substituted; ##STR4## is a 5-7 membered saturated or partially unsaturated heterocyclic radical containing at least 2 ring nitrogens, wherein the heterocyclic ting may optionally contain NR.sup.22 in the heterocyclic ring, and the ring carbons may optionally be substituted by alkyl, arylalkyl, halogen, --CF.sub.3, --OR.sup.14, or --CO.sub.2 R.sup.10 ;R.sup.22 is hydrogen, alkyl, or arylalkyl;m=0-6;n=1-6;p=0-6; andr=1-6with the proviso that R.sup.1 and R.sup.2 are both not hydrogen, or a pharmaceutically acceptable salt thereof which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent.