CO.sub.2 R.sub.9 in which R.sub.9 is hydrogen or lower alkyl, or --(CH.sub.2).sub.m NR.sub.9 R.sub.10 in which R.sub.9 and R.sub.10 are each independently hydrogen or lower alkyl and m is an integer of 0 to 6, p is an integer from 0 to 2, and r is an