R2, R3, R4, R5, and R6 are the same or different and each represents one member selected from the group consisting of hydrogen, a hydroxyl group, a substituted or unsubstituted aliphatic hydrocarbon group, and {TAIL ~ a substituted or unsubstituted aromatic hydrocarbon group}, provided that at least one R2 to R6 is a hydroxyl group; and wherein R1 represents one member selected from the group consisting of hydrogen, a substituted or unsubstituted aliphatic hydrocarbon group, and {HEAD ~ a substituted or unsubstituted aromatic hydrocarbon group}, 
R2 , R3 , R4 , R5 , and R6 are the same or different and each represents one member selected from the group consisting of hydrogen , a hydroxyl group , a substituted or unsubstituted aliphatic hydrocarbon group , and { TAIL ~ a substituted or unsubstituted aromatic hydrocarbon group } , provided that at least one R2 to R6 is a hydroxyl group ; and wherein R1 represents one member selected from the group consisting of hydrogen , a substituted or unsubstituted aliphatic hydrocarbon group , and { HEAD ~ a substituted or unsubstituted aromatic hydrocarbon group } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH