which may be the same or different, are: (a) hydrogen; (b) lower-alkyl having 1-6 carbon atoms inclusive; or (c) allyl;wherein R5 is: (a) hydrogen; or (b) R7 CH2 C(O)--;wherein R13 is hydrogen, hydroxy, alkoxy of 1 to 6 carbon atoms inclusive, or --OM wherein M is an alkali metal, alkyl of 1 to 6 carbon atoms, inclusive, or NR8.sup.??? R9 R10 R11, or HNR8.sup.??? R9 R10, or the pharmacologically