The present invention provides compositions comprising compounds having formula (I): and additionally provides methods for the use thereof in the treatment of various disorders including inflammatory or autoimmune disorders, and disorders involving malignancy or increased angiogenesis, wherein R1-R11, X, Y, Z, and n are as defined herein. In certain embodiments, the compositions are for systemic (e.g., oral) administration. In certain embodiments, methods for the treatment of various disorders including inflammatory or autoimmune disorders comprise systemically (e.g., orally) administering to a subject in need thereof a therapeutically effective amount of a compound of formula (I).