Michael adduct amino esters as total base number boosters for marine diesel engine lubricating compositions

A lubricating composition suited to use in a marine diesel engine includes an oil of lubricating viscosity and an amino carboxylate compound of formula (I): NR1R2-((CHR3)xNR4)n-(CHR5)2-COY, where R1 and R2 are independently selected from -(CHR6)2-COY′, H, and C1C3 alkyl and wherein at least one of R1 and R2 is -(CHR6)2-COY′; or wherein NR1R2 is a cyclic structure; Y and Y′ are independently selected from -OR7, NHR7, and -N(R7)2; each R7 is independently selected from C6-C12 alkyl and C6-C12 alkenyl; R3, R5 and R6 are independently selected from H and C1-C4 alkyl; R4 is selected from H, C1-C4 alkyl, and (CHR3)xNH2; x is from 2 to 4; and n is at least 1, except where NR1R2 is a cyclic structure, where n is at least 0.