2885-10-1Relevant articles and documents
Manganese (Mn2+)-dependent storage stabilization of Rhodotorula glutinis phenylalanine ammonia-lyase activity
Wall, Mark J.,Quinn, Andrew J.,D'Cunha, Godwin B.
, p. 894 - 902 (2008)
Phenylalanine ammonia-lyase (PAL; E C 4.3.1.5) reverse reaction has been exploited for the commercial production of optically pure L-phenylalanine from trans-cinnamic acid. Optimal conditions for the growth and PAL activity of Rhodotorula glutinis cells a
Synthesis, self-assembly, bacterial and fungal toxicity, and preliminary biodegradation studies of a series of l-phenylalanine-derived surface-active ionic liquids
Kapitanov, Illia V.,Jordan, Andrew,Karpichev, Yevgen,Spulak, Marcel,Perez, Lourdes,Kellett, Andrew,Kümmerer, Klaus,Gathergood, Nicholas
supporting information, p. 1777 - 1794 (2019/04/08)
We report for the first time a comprehensive study on the synthesis (supported by green chemistry metrics), aggregation properties, bacterial/fungal toxicities and preliminary data on biodegradation of a series of 24 l-phenylalanine derived surface-active ionic liquids (SAILs). The various cationic headgroups included pyridinium, imidazolium, and cholinium groups and enabled a comprehensive analysis of the effect of the alkyl ester chain (from C2 to C16) on the synthesis, toxicity, biodegradability, and surfactant properties of the novel SAILs. The evaluation of the SAILs revealed that a wide variety of properties were strictly dependent on the side chain length, including their bacterial and fungal toxicities (from low toxicity to high toxicity), and aggregation properties. Addition of the l-phenylalanine moiety which connects the lipophilic side chain to the cationic head group results in the phenyl group essentially contributing to the self-assembling properties. The interplay of dispersion interactions of the phenyl ring and the side chain hydrophobicity allows us to rank the novel SAILs (thus identifying the remarkable ones) as compared to other surfactants. The CMC values for the SAILs reported in this study are significantly (up to 10 times) lower than those reported for conventional surfactants with the same length of the side chain. Adsorption and micellization are among the factors affecting the toxicity of the studied SAILs. Preliminary biodegradation studies have shown that no clear trend was observed when comparing the closed bottle test results of the SAIL C2 and C10 derivatives. Medium chain length (C6 to C8) pyridinium SAILs have been recommended as the most prospective green alternatives for conventional cationic surfactants. These findings can contribute to designing new efficient amphiphiles with optimized antimicrobial activities and to employ them as potential environmentally benign mineralisable surfactants.
Synthesis, micellisation and interaction of novel quaternary ammonium compounds derived from L-Phenylalanine with 1,2-dipalmitoyl-sn-glycero- 3-phosphocholine as model membrane in relation to their antibacterial activity, and their selectivity over human red blood cells
Joondan, Nausheen,Caumul, Prakashanand,Akerman, Matthew,Jhaumeer-Laulloo, Sabina
, p. 117 - 129 (2015/02/05)
A series of quaternary ammonium compounds (QUATS) derived from L-Phenylalanine have been synthesized and their antibacterial efficiencies were determined against various strains of Gram-positive and Gram-negative bacteria. The antibacterial activity increased with increasing chain length, exhibiting a cut-off effect at C14 for Gram-positive and C12 for Gram-negative bacteria. The L-Phenylalanine QUATS displayed enhanced antibacterial properties with a higher cut-off point compared to their corresponding L-Phenylalanine ester hydrochlorides. The CMC was correlated with the MIC, inferring that micellar activity contributes to the cut-off effect in antibacterial activity. The hemolytic activities (HC50) of the QUATS against human red blood cells were also determined to illustrate the selectivity of these QUATS for bacterial over mammalian cells. In general, the MIC was lower than the HC50, and assessment of the micellar contribution to the antibacterial and hemolytic evaluation in TBS as a common medium confirmed that these QUATS can act as antibacterial, yet non-toxic molecules at their monomer concentrations. The interaction of the QUATS with the phospholipid vesicles (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) in the presence of 1-anilino-8-naphthalene sulfonate (ANS) and 1,6-diphenyl-1,3,5-hexatriene (DPH) as fluorescence probes showed that the presence of the quaternary ammonium moiety causes an increase in hydrophobic interactions, thus causing an increase in antibacterial activity.
