Newsletter 02/2025 edited by Loredano Pollegioni

Do you have news concerning the D-amino acids field to announce? Is there a relevant published paper to mention? Write us and take the advantage of this bimonthly Newsletter.

The Editor’s pick selection of the most intriguing papers is highlighted in yellow.

D-AAs AND PATHOLOGIES:

Detection of Fast Decliner of Diabetic Kidney Disease Using Chiral Amino AcidProfiling: A Pilot Study

Hirakawa Y, Kimura T, Sakai S, Mizui M, Mita M, Isaka Y, Nangaku M, Inagi RChem Biodivers. 2025 Jan 30:e202403332. doi: 10.1002/cbdv.202403332.

D-amino acids (D-AAs) have been reported to reflect kidney conditions but their efficacy in treating diabetickidney disease (DKD) has not been demonstrated. Here, the potential role of D-AAs as progression markers forDKD was investigated collecting the longitudinal estimated glomerular filtration rate (eGFR) data of 135patients. Fast decliners (FDs) were defined the patients exhibiting >10% decline from baseline eGFR per year: D-AAs could predict FDs independently of creatinine levels. In patients with DKD, D-serine, D-alanine, and D-proline were only detected in the blood, while 15 D-AAs were detected in the urine. Blood D-serine and urine D-AAs levels characterized DKD. Baseline blood D-serine levels and ratios did not differ between the FD and non-FD groups, while different short-term changes in blood D-serine levels were observed.

Examination of the relationship between D-amino acid profiles and cognitivefunction in individuals with mild cognitive impairment: A machine learning approach

Sugiki S, Tsuchiya S, Kimura R, Katada S, Misawa K, Tsujimura H, Hibi MInt J Neuropsychopharmacol. 2025 Mar 15:pyaf016. doi: 10.1093/ijnp/pyaf016.

In this paper, a cross-sectional study was conducted with 200 participants aged 50-89 years, classified intocognitively normal and mild cognitive impairment (MCI)-suspected groups based on Mini Mental StateExamination scores. Nonlinear models (kernel SVM and ANN) that combined D-amino acid profiles with subjectinformation achieved the highest area under the curve values of 0.78 and 0.79, respectively, demonstrating thatthe combination of D-amino acid profiles and non-invasive subject information is effective in detecting MCI.This approach could represent a cost-effective preliminary screening method before more invasive andexpensive diagnostic tests, thus contributing to the early detection and development of intervention strategiesfor dementia.

The Potential Mechanism of D-Amino Acids – Mitochondria Axis in the Progression of Diabetic Kidney Disease

Thuy Linh H, Nakade Y, Wada T, Iwata YKidney Int Rep. 2024 Nov 14;10(2):343-354. doi: 10.1016/j.ekir.2024.11.008.

Diabetic kidney disease (DKD) is a major complication of diabetes mellitus (DM) and the leading cause of end-stage renal disease. There is increasing evidence that mitochondrial dysfunction contributes to the developmentand progression of DKD. Accumulating evidence also demonstrates that D-AA levels in blood or urine couldserve as biomarkers for renal function. This review reports on the relationships between D-AAs and mitochondrial dysfunction and proposes a potential interaction and contribution of the D-AAs-mitochondria axis in DKD pathophysiology and progression.

Interpretable machine learning to evaluate relationships between DAO/DAOA (pLG72) protein data and features in clinical assessments, functional outcome, and cognitive function in schizophrenia patients

Lin CH, Lin E, Lane HY
Schizophrenia (Heidelb). 2025 Feb 22;11(1):27. doi: 10.1038/s41537-024-00548-z.
Machine learning has been proposed to utilize D-amino acid oxidase (DAAO) and pLG72 (also named DAO activator DAOA) protein levels to ascertain disease status in schizophrenia. This work reports on an interpretable machine learning (IML) framework to analyze DAAO/pLG72 levels of 380 Taiwanese schizophrenia patients, also including 27 parameters encompassing demographic variables, clinical assessments, functional outcomes, and cognitive function as features. DAAO levels showed significant associations with the 17-item Hamilton Depression Rating Scale (HAMD17), while Lasso model identified four features (HAMD17, age, working
memory, and overall cognitive function) and highlighted HAMD17 as the most significant one. Concerning pLG72, the Lasso model also identified four features (overall cognitive function, Scale for the Assessment of Negative Symptoms 20-item, quality of life scale), and category fluency-and highlighted overall cognitive function as the most significant feature.

Evolution of D-amino acid oxidase inhibitors: From concept to clinic

Bajaj A, Tsukamoto T Adv Pharmacol. 2025;102:301-345. doi: 10.1016/bs.apha.2024.10.016.

This review reports on D-amino acid oxidase (DAAO), especially on the production of more potent and drug-likeDAAO inhibitors with greater translational potential. Some of these inhibitors were investigated in a range ofpreclinical in vivo studies to assess pharmacokinetics, pharmacodynamics, and behavioral pharmacology. Thesestudies culminated with the discovery of TAK-831 (luvadaxistat), an orally available brain-penetrant DAAOinhibitor currently under clinical development.

Potential application of the D-amino acid oxidase (DAAO) inhibitor sodiumbenzoate for individuals experiencing psychological stress after traumaticevents

Lin SH, Abdullah M, Huang LC, Yang YKAdvancements in Life Sciences. 2025;12 (1):271-274, doi: 10.62940/ALS.V12I1.3310.

Preventing post-traumatic stress disorder (PTSD) is an urgent issue: on this side, the glutamatergic system couldbe a potential pathway. The D-amino acid oxidase (DAAO) inhibitor sodium benzoate is therapeuticallyeffective for certain mental disorders. Studies indicated a medium effect size on the perceived stress and28%-61% reduction of panic symptoms. The authors proposed the: “proper use of sodium benzoate in thepreparation of rations for individuals with mental disorders who will be or are currently exposed to stressorscould be a feasible method for preventing PTSD and other associated mental disorders”.

D-AAS & PHYSIOLOGICAL ROLES:

D-Alanine, a Circadian Metabolite that Regulates Glucose Metabolism andViral Infection

Kimura T, Sakai S, Isaka Y Chembiochem. 2025 Feb 18:e202500018. doi: 10.1002/cbic.202500018.

This review summarizes the physiological roles of D-alanine (D-Ala) as a circadian metabolite. Recent findingshave revealed that the regulation of circadian rhythm by D-Ala is vital for correcting blood glucose levels indiabetic conditions. In viral infections, D-Ala serves as a sensitive biomarker that reflects the severity of theinfection. D-Ala supplementation alleviates the progression of viral infections, acts as a circadian regulator andexerts a wide range of physiological effects.

Biological function of D-tryptophan: a bibliometric analysis and review

Wang F, Du R, Shang YFront Microbiol. 2025 Jan 13;15:1455540. doi: 10.3389/fmicb.2024.1455540.

This review focuses on D-tryptophan (D-Trp) roles in organic and medicinal chemistry and food science. D-Trprepresents a non-nutritional sweetener and a food preservative, as well as an inhibitor of the growth ofbacterial biofilms. Furthermore, D-Trp plays a role in the therapy of atherosclerosis, osteoporosis, tuberculosis,and cancer.

DAAO Mutant Sites among Different Mice Strains and Their Effects on EnzymeActivity

Yu-Cong Z, Sheng-Ling F, Hao LProtein Journal. 2025 44 (1), pp. 102 – 112. doi: 10.1007/s10930-024-10235-8.

Five nucleotide mutations were distributed in exons 2, 8, 9, 10 of D-amino acid oxidase encoding gene in C57mice: three mutations located on exons 8 and 9 were synonymous, and the remaining two in exons 2 (V64A) and10 (R295H) were non-synonymous mutations. These two point-substitutions increased the affinity of C57 DAAOwith substrate and enhanced its catalytic efficiency. Furthermore, decreased IC50 value for various inhibitorswas reported for C57 DAAO than for Balb/c and other DAAO mutants.

D-AAS & CHIRALITY:

Chiral Competition Reflected by Circularly Polarized Luminescence SignalInversion in Supramolecular Assembly of Pyrene-Amino Acid Derivatives and γ-Cyclodextrin

Zhang Y, Sun Y, Li H, Dong H, Dou M, Li T, Liu J, Kong J, Li YChemistry. 2025 Mar 10:e202500804. doi: 10.1002/chem.202500804.

The chiral competitive effect between carbohydrates and amino acids through the host-guest complexformation was studied by using amino acid modified pyrene derivatives and naturally occurring γ-cyclodextrin(γ-CD) as chiral sources, and the circularly polarized luminance (CPL) as indicator. Supramolecular complexesof achiral 1-pyrenebutyric acid and L-amino acid-pyrene derivatives with γ-CD exhibited positive CPL signals,with chirality derived from γ-CD’s stereochirality. In contrast, supramolecular complexes formed by D-aminoacid(D-AA)-pyrene derivatives with γ-CD showed a negative CPL signal, reflecting chiral competition betweenD-AAs and D-glucose in γ-CD; the amino acids stood out as the dominant chiral source in chiral competitionwith carbohydrates. The depth of insertion and stacking arrangement of the guest molecules within the γ-CDcavity played an essential role for the CPL inversion: chiral competition only occurred between D-AAs and D-carbohydrates, while cooperation was observed between L-amino acids and D-carbohydrates, which wereconsistent with the natural chirality bias.

D-AAS & BIOTECHNOLOGY:

Differential aortic aneurysm formation provoked by chemogenetic oxidativestress

Das AA, Waldeck-Weiermair M, Yadav S, Spyropoulos F, Pandey A, Dutta T, Covington TA,Michel TJ Clin Invest. 2025 Mar 18:e188743. doi: 10.1172/JCI188743.

Here, a chemogenetic approach was used to create an animal model of aortic aneurysm formation using atransgenic mouse line DAAO-TGTie2 expressing yeast D-amino acid oxidase (DAAO) under control of theendothelial Tie2 promoter. When DAAO-TGTie2 mice were chronically fed D-alanine, the animals becomehypertensive and developed abdominal but not thoracic aortic aneurysms: hydrogen peroxide production in theendothelium leads to oxidative stress throughout the vascular wall. Proteomics showed that protein kinase JNK1was dephosphorylated by the phophoprotein phosphatase DUSP3 in abdominal but not thoracic aorta, causingactivation of KLF4-dependent transcriptional pathways that trigger phenotypic switching and aneurysmformation. Pharmacological DUSP3 inhibition completely blocked aneurysm formation caused by chemogeneticoxidative stress.

Versatile Features of an Antibody Mimetic Peptide and Its Variants

Dolles S, Leukel S, Gensberger-Reigl S, Rohrhofer A, Rauch-Wirth L, Kaygisiz K, SynatschkeCV, Münch J, Schmidt B, Pischetsrieder M, Eichler JJ Pept Sci. 2025 Mar;31(3):e70005. doi: 10.1002/psc.70005.

The authors had previously designed a functional mimic of the broadly neutralizing HIV-1 antibody b12 thatrecognizes the CD4 binding site of the HIV-1 envelope glycoprotein gp120. Here, a variant of the b12 mimeticpeptide composed mostly of D-amino acids was shown to be stable towards proteolytic degradation, while didnot alter the binding and HIV-1 neutralizing properties. Furthermore, a peptide variant in which aspartateresidues were replaced with lysine ones strongly enhanced infection of cells with HIV-1 and GALV glycoproteinpseudotyped viral vectors, respectively: this peptide could facilitate retroviral gene transfer.

Effects of D-Amino Acid Replacements on the Conformational Stability ofMiniproteins

Xu R, Huang J, Kuhn AJ, Gellman SHChembiochem. 2025 Feb 13:e202500085. doi: 10.1002/cbic.202500085.

This study investigated the effects of L-to-D amino acid substitutions on tertiary structure stability for twominiproteins (a single-site variant of the chicken villin headpiece subdomain VHP and the human Pin1 WWdomain). For VHP, which features an α-helix-rich tertiary structure, substitutions led to significantdestabilization, while for WW, which has a β-sheet-rich tertiary structure, most single L-to-D changes seemed tocause complete unfolding at room temperature.

Imine Synthesis by Engineered D-Amino Acid Oxidase from Porcine Kidney

Khangkhachit W, Shirai S, Iwasaki G, Asano Y
ACS Omega. 2025 Jan 10;10(2):2212-2221. doi: 10.1021/acsomega.4c09160.

Various symmetric and asymmetric imines were synthesized using the novel amine oxidase represented byvariants of porcine kidney D-amino acid oxidase (pkDAAO; Y228L/R283G and I230A/R283G). Active primaryimines produced as intermediates in the oxidation of methylbenzylamine (MBA) derivatives were trapped byaliphatic, aromatic amines and diamines as nucleophiles forming new imines. (R)-Fluoro-MBA was the bestsubstrate for symmetric imine synthesis provided almost stoichiometric conversion (100 mM) and achievingnearly 100% yield. Several (R)-MBA derivatives were used as substrates, and the corresponding symmetric andasymmetric imines were synthesized.

Amino Acid-Mediated Enantioselective Synthesis of a BicyclicKetocarbaldehyde: Theoretical and Experimental Insights into a KeyIntermediate for Some Polycyclic Diterpene Synthesis

Leonelli F, Vetica F, Bodo E, Russo S, Michelini L, Sturabotti E, Mazzoccanti G, Ciogli A,Demitri N, Lamba D, Masi A, Migneco LM, Bettolo RMEur J Org Chem. 2025 28 (9): art. no. e202401291, doi: 10.1002/ejoc.202401291.

This work focuses on the amino acid-mediated intramolecular cyclization of a diketoaldehyde (2) to form abicyclic ketocarbaldehyde (1), a potentially useful intermediate in the synthesis of some polycyclic diterpenes.This cyclization exhibits a peculiar enantio-selectivity due to its product being the (S)-enantiomer when usingD-amino acids. The transformation proceeds through two irreversible steps: the cyclization and the subsequentdehydration process. The authors optimized the reaction enantiomeric excess by acting on the amino acids,solvents, and acids used: aldol intermediates were isolated.

ENZYMES ACTIVE ON D-AAS:

Directed Evolution and Unusual Protonation Mechanism of Pyridoxal Radical C-C Coupling Enzymes for the Enantiodivergent Photobiocatalytic Synthesis ofNoncanonical Amino Acids

Cheng L, Bo Z, Krohn-Hansen B, Yang YJ Am Chem Soc. 2025 Feb 5;147(5):4602-4612. doi: 10.1021/jacs.4c16716.

In this work, through high-throughput photobiocatalysis, a set of stereochemically complementary PLP radicalenzymes were evolved to allow the synthesis of both L- and D-amino acids with enhanced enantiocontrol acrossa broad pH window. These newly engineered enzymes allowed the use of a broad range of organoboronsubstrates, including boronates, trifluoroborates, and boronic acids, with excellent efficiency. The promiscuousracemase activity previously unveiled, was abolished in the evolved amino acid synthases. Mechanisticinvestigations suggest a switch of proton donor to account for the stereoinvertive formation of D-amino acids,highlighting an unusual stereoinversion mechanism.

D-AAS IN BACTERIA:

Identification and Characterization of a Novel D-Branched-Chain Amino Acids Importer from Lactobacillus fermentum

Aoki K, Mutaguchi Y, Hemmi H, Yoshimura T, Ito TChembiochem. 2025 Mar 15;26(6):e202401075. doi: 10.1002/cbic.202401075.

Various lactic acid bacteria synthesize D-branched-chain amino acids (D-BCAA) during growth: the pyridoxalphosphate-dependent enzyme isoleucine 2-epimerase (ILEP) has been identified as the key enzyme responsiblefor D-BCAA biosynthesis. The genes encoding ILEP and an uncharacterized amino acid-polyamine-organocation(APC) family transporter are adjacent in several D-BCAA-producing bacteria. In this study, the APC familytransporter from Lactobacillus fermentum (LfAAP) was reported to function as a non-stereospecific BCAAimporter. Heterologous expression of LfAAP in a L. lactis strain, which lacks the ILEP-AAP genes operon,revealed that ILEP functions as both synthetic and catabolic enzyme for D-BCAA.

Genomics analysis of Vreelandella piezotolerans V23 reveals its role in D-aminoacids metabolism

Liu D, Gu TJ, Wang HQ, Liu ZK, Wang MQ, Lü JL, Wang XY, Wang P, Wang CMar Genomics. 2025 Apr 15;80:101179. doi: 10.1016/j.margen.2025.101179.

The genome of Vreelandella piezotolerans V23, a Gram-negative and aerobic bacterium isolated from coastalseawater of the Yellow Sea (China) was determined. Genomic analysis revealed that strain V23 possessedvarious genes responsible for D-amino acids metabolism and a pathway of synthesizing peptidoglycan from D-amino acids. Strain V23 has the capacity to utilize D-amino acids and to grow up with different D-amino acidsas the sole nitrogen source.

D-AAS IN PEPTIDES AND PROTEINS:

Structure-based design, synthesis and biological evaluation of a novel D-aminoacid-containing peptide inhibitor by blocking the RAD51-BRCA2 interaction forthe treatment of kidney cancer

Wang J, Guan L, Wang J, Yin S, Gao J, Zhang Y, Niu MM, Li J, Li YEur J Med Chem. 2025 Apr 5;287:117372. doi: 10.1016/j.ejmech.2025.117372.

RAD51 is involved in the homologous recombination of DNA double-strand breaks by being directed to single-stranded DNA through BRCA2 protein. Therefore, blocking the interaction between RAD51 and BRCA2 isconsidered a potential anticancer therapy. In this paper, a novel, potent and biostable D-amino acid-containing peptide inhibitor (RB-1) that blocks the RAD51-BRCA2 interaction through an integrated virtualscreening protocol, was produced. RB-1 had excellent binding affinity for RAD51, antiproliferative activity onvarious kidney cancer cell lines and less toxicity to normal cells, and antitumor effects by inhibiting HR repair.RB-1 also showed a good biological stability in mouse serum. In vivo studies showed that RB-1 can effectivelysuppress tumor growth in mice without causing serious systemic side effects.

Control the Gene Delivery and Anticancer Efficacy of Peptides through ChiralModulation

Wang Z, Yue L, Min J, Liu H, Zhang Y, Du Y, Su R, Qi W, Wang YNano Lett. 2025 Feb 19;25(7):2693-2701. doi: 10.1021/acs.nanolett.4c05572.

Here, the authors designed four chiral peptides by adjusting the chirality of different functional modules.Compared with homochiral peptides, the heterochiral peptides with chirality inversion in their hydrophobicdomain transformed into more hydrophobic assemblies in response to the highly expressed enzyme matrixmetalloproteinase 7 (MMP-7) in cancer cells and showed higher endosomal membrane disruption activity. Inaddition, the heterochiral peptides showed high efficiency and selectivity in delivering siRNA gene drugs andinhibiting cancer cell growth, achieving a mortality rate of 95% in cancer cells.

Ultra-short lipopeptides containing D-amino acid exhibiting excellent stabilityand antibacterial activity against Gram-positive bacteria

Zou J, Wang J, Gao L, Xue W, Zhu J, Zhang Y, Gou S, Liu H, Zhong C, Ni JEur J Med Chem. 2025 Apr 5;287:117341. doi: 10.1016/j.ejmech.2025.117341.

The stability of antimicrobial peptides hampers their application. Here, a series of ultra-short lipopeptides usingD-amino acid substitution of the ultra-short lipopeptide C12-RRW-NH2 (with antibacterial activity against Gram-positive bacteria) were synthesized. The ultra-short lipopeptide Lip7 with full D-amino acid demonstrated goodstability in protease, serum, and salt ion environments, as well as excellent antibacterial activity against Gram-positive bacteria, especially against methicillin-resistant Staphylococcus aureus, and a low propensity todevelop bacterial resistance. Lip7 could rapidly depolarize the bacterial cytoplasmic membrane, disrupt theintegrity of the bacterial membrane, promote the generation of reactive oxygen species, and ultimately result inbacterial death.

Effect of Glycosylation on the Enzymatic Degradation of D-Amino Acid-Containing Peptides

Cui S, Jin Z, Yu T, Guo C, He Y, Kan Y, Yan L, Wu LMolecules. 2025 Jan 21;30(3):441. doi: 10.3390/molecules30030441.

This study investigates the effects of glycosylation position, glycan number, and monosaccharide structure on theconformation and enzymatic degradation of D-amino acid-containing peptides, using KYNEtWRSED (5-t) as amodel peptide and six monosaccharides as model glycans. Glycosylation inhibited the enzymatic degradation of5-t in the presence of most serine-like proteases; however, in the presence of chymotrypsin, glycosylation withmodified monosaccharides (except for β-D-GalNAc) promoted the degradation of 5-t. Molecular dockinganalysis revealed that the hydrogen bonding and electrostatic interactions between the glycopeptide andchymotrypsin were markedly strengthened. This study highlights the potential of glycosylation to enhance thetherapeutic and biomedical applications of D-amino acid-containing peptides in disease treatment and drugdesign.

Cancer Targeting Radiopeptidomimetics in Molecular Nuclear Medicine

Satpati DMol Pharm. 2025 Mar 13. doi: 10.1021/acs.molpharmaceut.4c01180.

This review outlines the design of peptidomimetics by incorporation of D-amino acids (inverso), reversal of D-amino acid sequence (retro-inverso), and reversal of L-amino acid sequence (retro). Clinically successful radio-peptidomimetics prepared using the three approaches have been evaluated to elucidate the important role of
peptidomimetics in cancer management.

Fatty acid conjugated BimBH3 analogues with D‑amino acid substitution as
PTPN1 inhibitors with enhanced activity, biostability and orally available
potency for the treatment of diabetes

Gong L, Dong G, Zhang Q, Shi Y, Gu Z, Yang X, Gao X, Zheng Y, Zhang CBioorg Med Chem. 2025 Apr 15;121:118107. doi: 10.1016/j.bmc.2025.118107.

Protein tyrosine phosphatase non-receptor type 1 (PTPN1) is a crucial regulator of insulin and leptin signalingpathways. Lipidated/acylated BimBH3 core peptide analogues function as potent PTPN1 inhibitors with potentialfor once-weekly hypoglycemic efficacy in the treatment of type 2 diabetes mellitus (T2DM). Here, 14 lipidatedBimBH3 analogues incorporating D-amino acids were generated: some exhibited potent PTPN1 inhibitoryactivity, significant resistance to proteolytic degradation, and good stability in mouse plasma. Subcutaneousadministration of D-14 one led to a significant 26% reduction in blood glucose, while oral administrationachieved a 15% reduction. Further studies confirmed the strong binding affinity of D-amino acid-containingBimBH3 analogues for PTPN1, supporting their potential for sustained hypoglycemic effects.

Modulating Copper(II) Coordination and Antimicrobial Activity: Effects of D-Amino Acid Substitution and Retro-Inverso Modification in Human Saliva MUC7Peptide

Wątły J, Szarszoń K, Sabieraj M, Kola A, Wieczorek R, Janek T, Valensin DInorg Chem. 2025 Mar 19. doi: 10.1021/acs.inorgchem.5c00438.

In order to improve the therapeutic use of the antimicrobial fragments of MUC7, it was modified using D-aminoacids and the retro-inverso strategy. The bioinorganic chemistry of these systems with Cu(II) and theirantimicrobial activity against fungal and bacterial strains were studied. The results demonstrated that the”standard” enantiomeric exchange and retro-inverso modifications of the MUC7 fragment had a minimal effecton the secondary structure and biological activity of the peptides and their Cu(II) complexes, while stronglyaffecting the thermodynamic stability.

Research on enhancing enzymatic degradation of anti-digestive peptidescontaining D-amino acids through N-terminal acetylation

Cui S, Guo C, Yan L, He Y, Wu LBioorg Chem. 2025 May;158:108337. doi: 10.1016/j.bioorg.2025.108337.

This study investigated the impact of N-terminal acetylation on the enzymatic hydrolysis of peptidesincorporating D-amino acids. Enzymatic activity assessments showed that N-terminal acetylation greatlypromoted the enzymatic breakdown of these peptides by Proteinase K, with a 17-fold increase in the substratedecay rate constant for the acetylated peptide Ac-6-w. This enhancement was specific to serine-type proteases: the N-terminal acetylation improved interactions within the catalytic triad of serine proteases, leading to faster enzymatic degradation.

Design, synthesis, and biological evaluation of novel and highly potent peptidestargeting syntenin

Zhou Y, Wang Y, Liu J, Bai Y, Ma J, Niu MM, Li J, Jiang HEur J Med Chem. 2025 Feb 25;289:117446. doi: 10.1016/j.ejmech.2025.117446.

Syntenin plays a critical role in renal cell carcinoma (RCC) progression, this pointing to its potential as atherapeutic target. In this paper, a novel, highly efficient, and stable peptide inhibitor (named PDPP-3 andcontaining D-amino acids) of syntenin was identified and investigated.

D-AAS AND ANALYTICAL METHODS:

Three-dimensional high-performance liquid chromatographic determination ofserine, threonine and allothreonine enantiomers in mouse tissues andphysiological fluids

Oyaide M, Akita T, Ishii C, Mita M, Hamase KJ Pharm Biomed Analysis Open, 5, art. no. 100053 doi: 10.1016/j.jpbao.2025.100053.

The serine, threonine and allothreonine (aThr) enantiomers levels were determined in 6 tissues (cerebrum,cerebellum, medulla oblongata, pancreas, liver and kidney) and 2 physiological fluids (plasma and urine) of miceusing a highly-selective three-dimensional high-performance liquid chromatographic (3D-HPLC) system. For Ser,the presence of the D-form could be determined in all the tissues and physiological fluids, and for D-Thr and D-aThr the presence in the cerebrum and urine was also demonstrated. Trace levels of D-Thr and D-aThr weredetected in the other tissues and plasma. The results show that these D-amino acids are widely present inmammalian tissues and physiological fluids.

Electrochemical reduction boosted Luminol cathodic electrochemiluminescencefor trace chiral recognition of alanine enantiomers

Tian T, Chen L, Li T, Wang X, Yang S, Wang H, Jiang Y, Yao X, Zhao H, Wang D, Li XBioelectrochemistry. 2025 Feb 19;165:108945. doi: 10.1016/j.bioelechem.2025.108945.

Electrochemiluminescence (ECL)-based chiral sensors highly desire a sensitive sensing interface: actually, theECL emission based on a luminol-dissolved O system shows the drawback of weak emission. Herein, anamplification strategy of ECL emission was proposed. The chiral ECL sensing interface combines the chiralrecognition of D-amino acid oxidase (DAAO) with the signal transduction and amplification of CdS/CNTs-enhanced ECL emission. During DAAO-catalyzed enantioselective-oxidations of alanine, dioxygen is convertedto hydrogen peroxide, which tunes the ROS generation. By the optimized system, alanine enantiomers arediscriminated and L-alanine is detected (detection limit of 0.014 fM).

INFORMATION

The D-amino acids International Research Center “DAAIR“ has been established in Gerenzano (Varese, Italy) in 2019 with the aim to support and perform scientific research projects and activities on the field of D-amino acids. The Center, located inside the Fondazione Istituto Insubrico Ricerca per la Vita, is aimed to represent a pole of excellence at international level for dissemination and research involving the D-amino acids (Director Silvia Sacchi).

Info@d-aminoacids.com

director@d-aminoacids.com

D-AMINO ACIDS INTERNATIONAL RESEARCH CENTER

INFO@D-AMINOACIDS.COM