A compound of the structure ##STR1## wherein R.sup.1 and R.sup.2 are each, independently, hydrogen, --CONH--[(CR.sup.3 R.sup.4).sub.m (--A--(CR.sup.5 R.sup.6).sub.n).sub.p ].sub.q --B; ##STR2## R.sup.3, R.sup.4, R.sup.5, R.sup.6, and B are each, independently, hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylaminoalkyl, dialkylaminoalkyl, arylalkyl, cycloalkyl, --OR.sup.7, --SR.sup.7, halogen, --CN, --NO.sub.2, --CF.sub.3, --COR.sup.7, --CO.sub.2 R.sup.7, --CONHR.sup.7, --SO.sub.2 R.sup.7, --OSO.sub.3 R.sup.7, --NR.sup.7 R.sup.8, --NHCOR.sup.7, --NHSO.sub.2 R.sup.7, or Ar;R.sup.7 and R.sup.8 are each, independently, hydrogen, alkyl, arylalkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylaminoalkyl, dialkylaminoalkyl, cycloalkyl;R.sup.9 and R.sup.10 are each, independently, alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylaminoalkyl, dialkylaminoalkyl, arylalkyl, --CF.sub.3, --COR.sup.7, --CO.sub.2 R.sup.7, --CONHR.sup.7, --SO.sub.2 R.sup.7, or Ar;A is --CH.sub.2 --, --NR.sup.7 --, --O--, --S--, --SO--, --SO.sub.2 --, --PR.sup.7 --, --CO--, --NHCO--, --NHSO--, or --P(O)(R.sup.7)--;Ar is phenyl, naphthyl, pyridyl, quinolyl, isoquinolyl, quinoxalyl, thienyl, thionaphthyl, furyl, benzofuryl, benzodioxyl, benzoxazolyl, benzoisoxazolyl, indolyl, thiazolyl, isoxazolyl, pyrimidinyl, pyrazinyl, imidazolyl, benzopyranyl, benz[b]thiophenolyl, benzimidazolyl, benzthiazolyl, benzodioxolyl, piperidinyl, morpholinyl, piperazinyl, tetrahydrofuranyl, or pyrrolidinyl; wherein the Ar group may be optionally mono-, di-, or tri- substituted; ##STR3## is a nitrogen containing heterocycle that may be saturated, unsaturated, or partially unsaturated, and may be optionally mono-, di-, or tri- substituted; with the proviso that R.sup.1 and R.sup.2 are not both hydrogen;m=0-6;n=0-6;p=0-1;q=0-1;or a pharmaceutically acceptable salt thereof which is useful as an immunosuppressive, antiinflammatory, antifungal, antiproliferative, and antitumor agent.