Table 1.

MALDI-ToF peaks interpretation. NaOH-catalysed reaction of catechin and hexamethylenediamine at 100 °C *.

289.9 Da = Catechin alone

509–512 Da = catechin-(hexamethylenediamine)2 (509 Da calculated)

524.6 Da = catechin-(hexamethylenediamine)2 ionic salt

526 Da = 524 diprotonated

552.8 Da = catechin-(hexamethylenediamine)2 + 3 × Na+ (calculated 553 Da)

579.7 Da = catechin-(hexamethylenediamine)2 + 4 × Na+ (calculated 582 Da)

602.7 Da = catechin dimer + Na+ (calculated 601 Da)

605 Da = catechin-(hexamethylenediamine)3 + Na+

631.6–633.7 Da = catechin-(hexamethylenediamine)3 + 2 × Na+ (calculated 630 Da)

664 Da = catechin-hexamethylenediamine-catechin (660 Da calculated)

However, also:

638 + 1 × Na+ = catechin-(hexamethylenediamine)3 ionic salt (calculated 661 Da)

678 Da = catechin-(hexamethylenediamine)3 + 4 × Na+ (calculated 675 Da)

758 Da = catechin-hexamethylenediamine-catechin-hexamethylenediamine

798 Da = catechin-(hexamethylenediamine)4 + 2 × Na+, ionic salt.

1169 Da = hexamethylenediamine-catechindimer-hexamethylenediamine-catechin-hexamethylenediamine + 1 × Na+

1459 Da = hexamethylenediamine-catechindimer-hexamethylenediamine-catechindimer-hexamethylenediamine, diprotonated

* In the spectra, there is a clear period of 40 Da. This is a diamine with 2Na⁺, thus 116 + 23+ 23 − 2 = 160 Da, thus with 2 × Na⁺, not an unusual occurrence. Also, 160/4 = 40 Da period, thus a series 798-758-718-678-634-594-553(small)-513 Da Thus, 513 + 160 = 673 Da (678 Da); thus 594 + 160 = 754 Da (758 Da). This is a salt 4 × 117 = 755 Da; thus 638 + 160 = 798 Da = 755 Da + 2Na⁺ = 801 Da − 2H⁺ = 799 Da.