Complex sentence: Marcus painted portraits many people associated with the arts including collectors, critics and artists such as Jill Johnston, Red Grooms, Lucas Samaras, Willem De Kooning, Sari Dienes Henry Geldzahler, Myron Stout Bob Thompson and Roy Neuberger to name a few.
Split into simpler sentences: Marcus painted portraits of many people associated with the arts including collectors, critics and fellow artists. Among those Marcus depicted were Jill Johnston, Red Grooms, Lucas Samaras, Willem De Kooning, Sari Dienes Henry Geldzahler, Myron Stout Bob Thompson and Roy Neuberger to name a few.