Comparison of zwitterionic N-alkylaminomethanesulfonic acids to related compounds in the Good buffer series

Abstract

SummarySeveral N-alkyl and N,N-dialkylaminomethanesulfonic acids were synthesized (as zwitterions and/or sodium salts) to be tested for utility as biological buffers at lower pH levels than existing Good buffer compounds (aminoalkanesulfonates with a minimum of two carbons between amine and sulfonic acid groups as originally described by Norman Good, and in common use as biological buffers). Our hypothesis was that a shorter carbon chain (one carbon) between the amino and sulfonic acid groups should lower the ammonium ion pK a values. The alkylaminomethanesulfonate compounds were synthesized in aqueous solution by reaction of primary or secondary amines with formaldehyde/sodium hydrogensulfite addition compound. The pK a values of the ammonium ions of this series of compounds (compared to existing Good buffers) was found to correlate well with the length of the carbon chain between the amino and sulfonate moeties, with a significant decrease in amine basicity in the aminomethanesulfonate compounds (pK a decrease of 2 units or more compared to existing Good buffers). An exception was found for the 2-hydroxypiperazine series which shows only a small pK a decrease, probably due to the site of protonation in this compound (as confirmed by X-ray crystal structure). X-ray crystallographic structures of two members of the series are reported. Several of these compounds have pK a values that would indicate potential utility for buffering at pH levels below the normal physiological range (pK a values in the range of 3 to 6 without aqueous solubility problems) – a range that is problematic for currently available Good buffers. Unfortunately, the alkylaminomethanesulfonates were found to degrade (with loss of their buffering ability) at pH levels below the pK a value and were unstable at elevated temperature (as when autoclaving) – thus limiting their utility.

Tunable Loading of Oligonucleotides with Secondary Structure on Gold Nanoparticles through a pH-Driven Method

“…HEPES is a zwitterionic buffer with two dissociation constants: one at the piperazine ring (p K a = 7.5) and one at the sulfonate group (p K a = 2). 27,28 Thus, the net charge of HEPES can be tuned over a range of pH. As-synthesized AuNS are coated by HEPES capping layers, and the NP surface charge can be determined by the overall charge of the adsorbed HEPES.…”

“…15 At pH = 1.7 of the citrate solution, protonation at the piperazine ring (N1 and N4) and the sulfonate group resulted in an increase of surface charge of AuNS (ζ = −16.6 ± 0.97 mV) (Supporting Information Figure S2). The charge of the HEPES molecule, however, decreased at higher pH due to deprotonation at N1, N4, and sulfonate, 28 which also resulted in a higher negatively charged surface of the AuNS (at pH = 7.9, ζ = −22.0 ± 0.24 mV) (Supporting Information Figure S2). …”

ТЕРМОДИНАМИКА ДИССОЦИАЦИИ АМИНОМЕТАНСУЛЬФОКИСЛОТЫ И ЕЕ N-Замещенных ПРОИЗВОДНЫХ В ВОДНЫХ РАСТВОРАХ ПРИ 293-313 K, "Журнал Физической Химии"

“…В биологических и биохимических исследованиях альтернативой классическим бу-ферным системам (фосфатная, цитратная, борат-ная и т.д. ), которые неприменимы из-за их ток-сичности или метаболического воздействия [3], для поддержания кислотности среды в диапазоне физиологических рН являются буферные раство-ры Н. Гуда [4]. Широкое применение в указанных исследованиях занимают соединения цвиттери-онного строения, например аминоалкансульфо-кислоты и их N-производные [5].…”

Electrochemical Properties of Aminomethanesulphonic Acid – Water System

“…Широкое применение для поддержания рН нашли аминоалкансульфоновое кислоты, их производные и соли [1,2,[4][5][6][7], в частности АМСК. Другие классы соединений (цитрат, борат и фосфат) в биологических исследованиях неприменимы из-за их токсичности или метаболического воздействия [7].…”

“…Широкое применение для поддержания рН нашли аминоалкансульфоновое кислоты, их производные и соли [1,2,[4][5][6][7], в частности АМСК. Другие классы соединений (цитрат, борат и фосфат) в биологических исследованиях неприменимы из-за их токсичности или метаболического воздействия [7]. Кроме того, АМСК, ее производные и соли -биологически активные вещества, проявляющие антимиотические, цитостатические, бактерицидные и инсектицидные свойства [8].…”