S1U1L1P3H4O1N1A1T1E1
15 points
SULPHONATE is validvalid
to react with sulphuric acid [v SULPHONATED, SULPHONATES, SULPHONATING]
a salt of sulphonic acid [n -S] / to convert into sulphonic acid, also SULFONATE [v SULPHONATED, SULPHONATING, SULPHONATES]