data <- "['oguma', 'makeup', u'\u0e27\u0e34\u0e15\u0e32\u0e21\u0e34\u0e19\u0e2b\u0e19\u0e49\u0e32\u0e40\u0e14\u0e47\u0e01', 'jeban',]"
data
gsub("u'[^[:ascii:]]+',?\\s*", "", data, perl=T)
ZGF0YSA8LSAiWydvZ3VtYScsICdtYWtldXAnLCB1J1x1MGUyN1x1MGUzNFx1MGUxNVx1MGUzMlx1MGUyMVx1MGUzNFx1MGUxOVx1MGUyYlx1MGUxOVx1MGU0OVx1MGUzMlx1MGU0MFx1MGUxNFx1MGU0N1x1MGUwMScsICdqZWJhbicsXSIKZGF0YQpnc3ViKCJ1J1teWzphc2NpaTpdXSsnLD9cXHMqIiwgIiIsIGRhdGEsIHBlcmw9VCk=