The invention provides a family of compounds useful as anti-infective agents and/or anti-proliferative agents, for example, chemotherapeutic agents, anti-fungal agents, anti-bacterial agents, anti-parasitic agents, anti-viral agents, and/or anti-inflammatory agents, and/or prokinetic (gastrointestinal modulatory) agents, having the formula: ##STR00001## or pharmaceutically acceptable salts, esters, or prodrugs thereof.