The present invention is directed to compounds of the general formula (1), wherein the integers are defined as follows: R1 is - (CH2) nCH (CH3) 2, R2 is - (CH2) n + 2CH (CH3) 2, G1 selected from monosaccharides with 4 to 6 carbon atoms, x in the range from 1.1 to 4, n is a number in the range from zero to 3.