Amino acids, betaines and related ammonium compounds in Neapolitan limmo, a Mediterranean sweet lime, also known as lemoncetta Locrese.

BACKGROUND: The so-called 'Neapolitan limmo' or 'lemoncetta Locrese' is an old and now rare Mediterranean sweet lime, similar to lemon but smaller. It is a fruit distinguished from orange, lemon, mandarin, and lime for its sweeter, watery, and non-acidic taste, with a pH between 5.6 and 5.9. No compositional studies are currently available for this citrus fruit. Here we report, for the first time, the distribution in the limmo juice of free amino acids and their main derivatives such as betaines and related ammonium compounds. RESULTS: Seven proteinogenic amino acids (proline, asparagine, serine, aspartic acid, glutamine, alanine, and threonine) and a non-protein amino acid (γ-aminobutyric acid) characterize Neapolitan limmo juice. Proline betaine is the predominant betaine. The data were compared with those of other important citrus juices. CONCLUSION: The specific 'taste quality' of Neapolitan limmo juice can be attributed to its peculiar composition in amino acids. The species-specific presence of the ammonium compound derivatives of the amino acid proline, with proline betaine as the predominant betaine, characterize the non-acidic varieties of Mediterranean sweet lime. Our study constitutes an important step towards the repopulation of this ancient plant and its exploitation in food industry. © 2020 Society of Chemical Industry.

The Ancient Neapolitan Sweet Lime and the Calabrian Lemoncetta Locrese Belong to the Same Citrus Species.

"Neapolitan limmo" is an ancient and rare sweet Mediterranean lime, now almost extinct but used until a few decades ago for the production of a fragrant liqueur called the "four citrus fruits". The objective of this work was to compare, through the use of chemical (flavonoids, volatile organic compounds, and chiral compounds) and molecular (DNA fingerprint based on RAPD-PCR) markers, the residual population of Neapolitan limmo with other populations of sweet limes, identified in Calabria and known as "lemoncetta Locrese". We report for the first time specific botanical characteristics of the two fruits and unequivocally show that the ancient sweet Mediterranean limes Neapolitan limmo and lemoncetta Locrese are synonyms of the same Citrus species. Owing to the biodiversity conserved in their places of origin, it will now be possible to recover, enhance and implement the use of this ancient sweet lime for agro-industrial purposes.

Ophthalmic acid is a marker of oxidative stress in plants as in animals.

BACKGROUND: Ophthalmic acid (OPH), γ-glutamyl-L-2-aminobutyryl-glycine, a tripeptide analogue of glutathione (GSH), has recently captured considerable attention as a biomarker of oxidative stress in animals. The OPH and GSH biosynthesis, as well as some biochemical behaviors, are very similar. Here, we sought to investigate the presence of OPH in plants and its possible relationship with GSH, known to possess multiple functions in the plant development, growth and response to environmental changes. METHODS: HPLC-ESI-MS/MS analysis was used to examine the occurrence of OPH in leaves from various plant species, and flours from several plant seeds. Different types of oxidative stress, i.e., water, dark, paraquat, and cadmium stress, were induced in rye, barley, oat, and winter wheat leaves to evaluate the effects on the levels of OPH and its metabolic precursors. RESULTS: OPH and its dipeptide precursor, γ-glutamyl-2-aminobutyric acid, were found to occur in phylogenetically distant plants. Interestingly, the levels of OPH were tightly associated with the oxidative stress tested. Levels of OPH precursors, γ-glutamyl-2-aminobutyric acid and 2-aminobutyric acid, the latter efficiently formed in plants via biosynthetic pathways absent in the animal kingdom, were also found to increase during oxidative stress. CONCLUSIONS: OPH occurs in plants and its levels are tightly associated with oxidative stress. GENERAL SIGNIFICANCE: OPH behaves as an oxidative stress marker and its biogenesis might occur through a biochemical pathway common to many living organisms.

Ergothioneine Antioxidant Function: From Chemistry to Cardiovascular Therapeutic Potential.

Ergothioneine (ESH), the betaine of 2-mercapto-L-histidine, is a water-soluble naturally occurring amino acid with antioxidant properties. ESH accumulates in several human and animal tissues up to millimolar concentration through its high affinity transporter, namely the organic cation transporter 1 (OCTN1). ESH, first isolated from the ergot fungus (Claviceps purpurea), is synthesized only by Actinomycetales and non-yeast-like fungi. Plants absorb ESH via symbiotic associations between their roots and soil fungi, whereas mammals acquire it solely from dietary sources. Numerous evidence demonstrated the antioxidant and cytoprotective effects of ESH, including protection against cardiovascular diseases, chronic inflammatory conditions, ultraviolet radiation damages, and neuronal injuries. Although more than a century after its discovery has gone by, our understanding on the in vivo ESH mechanism is limited and this compound still intrigues researchers. However, recent evidence about differences in chemical redox behavior between ESH and alkylthiols, such as cysteine and glutathione, has opened new perspectives on the role of ESH during oxidative damage. In this short review, we discuss the role of ESH in the complex machinery of the cellular antioxidant defense focusing on the current knowledge on its chemical mechanism of action in the protection against cardiovascular disease.

Experimental Evidence and In Silico Identification of Tryptophan Decarboxylase in Citrus Genus.

Plant tryptophan decarboxylase (TDC) converts tryptophan into tryptamine, precursor of indolealkylamine alkaloids. The recent finding of tryptamine metabolites in Citrus plants leads to hypothesize the existence of TDC activity in this genus. Here, we report for the first time that, in Citrus x limon seedlings, deuterium labeled tryptophan is decarboxylated into tryptamine, from which successively deuterated N,N,N-trimethyltryptamine is formed. These results give an evidence of the occurrence of the TDC activity and the successive methylation pathway of the tryptamine produced from the tryptophan decarboxylation. In addition, with the aim to identify the genetic basis for the presence of TDC, we carried out a sequence similarity search for TDC in the Citrus genomes using as a probe the TDC sequence reported for the plant Catharanthus roseus. We analyzed the genomes of both Citrus clementina and Citrus sinensis, available in public database, and identified putative protein sequences of aromatic l-amino acid decarboxylase. Similarly, 42 aromatic l-amino acid decarboxylase sequences from 23 plant species were extracted from public databases. Potential sequence signatures for functional TDC were then identified. With this research, we propose for the first time a putative protein sequence for TDC in the genus Citrus.

Sirtuins in vascular diseases: Emerging roles and therapeutic potential.

Silent information regulator-2 (Sir-2) proteins, or sirtuins, are a highly conserved protein family of histone deacetylases that promote longevity by mediating many of the beneficial effects of calorie restriction which extends life span and reduces the incidence of cancer, cardiovascular disease (CVD), and diabetes. Here, we review the role of sirtuins (SIRT1-7) in vascular homeostasis and diseases by providing an update on the latest knowledge about their roles in endothelial damage and vascular repair mechanisms. Among all sirtuins, in the light of the numerous functions reported on SIRT1 in the vascular system, herein we discuss its roles not only in the control of endothelial cells (EC) functionality but also in other cell types beyond EC, including endothelial progenitor cells (EPC), smooth muscle cells (SMC), and immune cells. Furthermore, we also provide an update on the growing field of compounds under clinical evaluation for the modulation of SIRT1 which, at the state of the art, represents the most promising target for the development of novel drugs against CVD, especially when concomitant with type 2 diabetes.

Vascular-homing peptides for targeted drug delivery and molecular imaging: meeting the clinical challenges.

The vasculature of each organ expresses distinct molecular signatures critically influenced by the pathological status. The heterogeneous profile of the vascular beds has been successfully unveiled by the in vivo phage display, a high-throughput tool for mapping normal, diseased, and tumor vasculature. Specific challenges of this growing field are targeted therapies against cancer and cardiovascular diseases, as well as novel bioimaging diagnostic tools. Tumor vasculature-homing peptides have been extensively evaluated in several preclinical and clinical studies both as targeted-therapy and diagnosis. To date, results from several Phase I and II trials have been reported and many other trials are currently ongoing or recruiting patients. In this review, advances in the identification of novel peptide ligands and their corresponding receptors on tumor endothelium through the in vivo phage display technology are discussed. Emphasis is given to recent findings in the clinical setting of vascular-homing peptides selected by in vivo phage display for the treatment of advanced malignancies and their altered vascular beds.

Stachydrine ameliorates high-glucose induced endothelial cell senescence and SIRT1 downregulation.

Hyperglycaemia, a characteristic feature of diabetes mellitus, induces endothelial dysfunction and vascular complications by accelerating endothelial cell (EC) senescence and limiting the proliferative potential of these cells. Here we aimed to investigate the effect of stachydrine, a proline betaine present in considerable quantities in juices from fruits of the Citrus genus, on EC under high-glucose stimulation, and its underlying mechanism. The senescence model of EC was set up by treating cells with high-glucose (30 mM) for different times. Dose-dependent (0.001-1 mM) evaluation of cell viability revealed that stachydrine does not affect cell proliferation with a similar trend up to 72 h. Noticeable, stachydrine (0.1 mM) significantly attenuated the high-glucose induced EC growth arrest and senescence. Indeed, co-treatment with high-glucose and stachydrine for 48 h kept the percentage of EC in the G0 /G1 cell cycle phase near to control values and significantly reduced cell senescence. Western blot analysis and confocal-laser scanning microscopy revealed that stachydrine also blocked the high-glucose induced upregulation of p16(INK4A) and downregulation of SIRT1 expression and enzyme activity. Taken together, results here presented are the first evidence that stachydrine, a naturally occurring compound abundant in citrus fruit juices, inhibits the deleterious effect of high-glucose on EC and acts through the modulation of SIRT1 pathway. These results may open new prospective in the identification of stachydrine as an important component of healthier eating patterns in prevention of cardiovascular diseases.

Proteomic profiles of the embryonic chorioamnion and uterine caruncles in buffaloes (Bubalus bubalis) with normal and retarded embryonic development.

The aim of this study was to compare the proteome profiles of the chorioamnion and corresponding caruncle for buffalo embryos that had either normal or retarded development on Day 25 after artificial insemination (AI). In experiment 1, embryos that were to subsequently undergo late embryonic mortality had a smaller width on Day 25 after AI than embryos associated with pregnancy on Day 45 after AI. In experiment 2, 25 Italian Mediterranean buffaloes underwent transrectal ultrasonography on Day 25 after AI, and pregnant animals were categorized as one of two groups based on embryonic width: normal embryos (embryonic width > 2.7 mm) and retarded embryos (embryonic width < 2.7 mm). Three buffaloes of each group were slaughtered on Day 27 after AI to collect chorioamnion and caruncle tissues for subsequent proteomic analyses. Two-dimensional difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometer analysis were used to ascertain the proteomic profiles. To confirm 2D-DIGE-results, three selected proteins were analyzed by Western blot. The proteomic profiles of the chorioamnion of retarded embryos and the corresponding caruncles showed differences in the expression of several proteins compared to normal embryos. In particular, a down-regulation was observed for proteins involved in protein folding (HSP 90-alpha, calreticulin), calcium binding (annexin A1, annexin A2), and coagulation (fibrinogen alpha-chain) (P < 0.05), whereas proteins involved in protease inhibition (alpha-1-antiproteinase, serpin H1, serpin A3-8), DNA and RNA binding (heterogeneous nuclear ribonucleoproteins A2/B1 and K), chromosome segregation (serine/threonine-protein phosphatase 2A), cytoskeletal organization (ezrin), cell redox homeostasis (amine oxidase-A), and hemoglobin binding (haptoglobin) were up-regulated (P < 0.05).

The methylarginines NMMA, ADMA, and SDMA are ubiquitous constituents of the main vegetables of human nutrition.

Endogenous methylarginines, N(G),N(G)-dimethyl-L-arginine (asymmetric dimethylarginine, ADMA), N(G)-N('G)-dimethyl-L-arginine (symmetric dimethylarginine; SDMA), and N(G)-monomethyl-L-arginine (monomethylarginine; NMMA) are supposed to be produced in human body through the methylation of protein arginine residues by protein arginine methyltransferases (PRMT) and released during proteolysis of the methylated proteins. Micromolar concentration of ADMA and NMMA can compete with arginine for nitric oxide synthase (NOS) reducing nitric oxide (NO) formation, whereas SDMA does not. Indeed, increased ADMA and SDMA plasma levels or a decreased arginine/ADMA ratio is related with risk factors for chronic kidney disease and cardiovascular disease. To the best of our knowledge the exogenous presence of methylarginines, like that in fruits and vegetables, has never been described so far. Here, we report the finding that methylarginines are ubiquitous in vegetables which represent an important part of human daily diet. Some of these vegetables contain discrete amounts of ADMA, SDMA, and NMMA. Specifically, among the vegetables examined, soybean, rye, sweet pepper, broad bean, and potato contain the highest ADMA and NMMA mean levels. Our results establish that the three methylarginines, in addition to being produced endogenously, can also be taken daily through the diet in conspicuous amounts. We propose that the contribution of the methylarginines contained in the vegetables of daily diet should be taken into account when the association between vegetable assumption and their levels is evaluated in clinical studies. Furthermore, a comprehensive understanding on the role of the digestive breakdown process and intestinal absorption grade of the methylarginines contained in vegetables is now needed.

Determination of homoarginine, arginine, NMMA, ADMA, and SDMA in biological samples by HPLC-ESI-mass spectrometry.

N(G),N(G)-dimethyl-L-arginine (ADMA) and N(G)-methyl-L-arginine (NMMA) are endogenous inhibitors of nitric oxide synthase (NOS). In contrast, N(G),N'(G)-dimethyl-L-arginine (SDMA) possesses only a weak inhibitory potency towards neuronal NOS and it is known to limit nitric oxide (NO) production by competing with L-arginine for cellular uptake. The inhibition of NOS is associated with endothelial dysfunction in cardiovascular diseases as well in chronic renal failure. L-homoarginine (HArg), a structural analog of L-arginine (Arg), is an alternative but less efficient substrate for NOS. Besides, it inhibits arginase, leading to an increased availability of L-arginine for NOS to produce NO. However, its relation with cardiovascular disease remains unclear. To date, several analytical methods for the quantitative determination of Arg, HArg, NMMA, AMDA, and SDMA in biological samples have been described. Here, we present a simple, fast, and accurate HPLC-ESI-MS/MS method which allows both the simultaneous determination and quantification of these compounds without needing derivatization, and the possibility to easily modulate the chromatographic separation between HArg and NMMA (or between SDMA and ADMA). Data on biological samples revealed the feasibility of the method, the minimal sample preparation, and the fast run time which make this method very suitable and accurate for analysis in the basic and clinical settings.

Endothelial progenitor cells express PAF receptor and respond to PAF via Ca(2+)-dependent signaling.

Endothelial progenitor cell (EPC) therapy is a promising approach to promote angiogenesis and endothelial repair in patients with cardiovascular diseases (CVD). However, their release of proinflammatory mediators may compromise the therapeutic efficacy. Little is known about the role of Platelet-Activating Factor (PAF) in EPC functional response. Here, we investigated the expression of PAF receptor (PAF-R) in early EPC and the release of PAF under stimulation with factors involved in endothelial dysfunction. Results indicated that early EPC express the PAF-R and respond to PAF signaling via a transient increase of cytoplasmic Ca(2+) concentration. EPC release PAF in a time dependent manner upon stimulation with tumor necrosis factor-alpha (TNF-alpha) or high-glucose concentration with a peak at 30 min and 10 min (p<0.01 vs. control), respectively. PAF, starting at concentration of 50 ng/ml, exerted a detrimental effect on EPC number with a concomitant increase of p38 activity. Furthermore, both the reduction of early EPC number and the enhanced p38 activity induced by PAF were abolished by CV3988, a PAF receptor antagonist. These novel findings, revealing that early EPC respond to PAF signaling, unveil an inflammatory pathway that may play a crucial role in the outcome of cardiovascular cell therapy with EPC.

Modification of the detrimental effect of TNF-α on human endothelial progenitor cells by fasudil and Y27632.

Exposure of human endothelial progenitor cells (EPCs) to tumor necrosis factor-α (TNF-α) reduced their number and biological activity. Yet, signal transduction events linked to TNF-α action are still poorly understood. To address this issue, we examined the possible effect of fasudil and Y27632, two inhibitors of Rho kinase pathway, which is involved in endothelial dysfunction, atherosclerosis, and in- flammation. Results demonstrated that incubation with fasudil starting from 50 µM but not Y27632 determined a dose-dependent improvement of EPC number during exposure to TNF-α (P < 0.05 vs. TNF-α alone). Analysis of the signal transduction pathway activated by TNF-α revealed that the increased expression of p-p38 was not significantly altered by fasudil. Instead, fasudil blocked the TNF-α induced phosphorylation of Erk1/2 (P < 0.05 vs. TNF-α) as well as the inhibitor of Erk1/2-specific phosphorylated form, i.e., PD98059 (P < 0.05 vs. TNF-α). These results were confirmed by analysis of these kinases by confocal microscopy. Finally, 2D-DIGE and MALDI-TOF/TOF analysis of EPCs treated with fasudil revealed increased expression levels of an actin-related protein and an adenylyl cyclase associated protein and decreased expression levels of proteins related to radical scavenger and nucleotide metabolism. These findings suggest that fasudil positively affects EPC number and that other major signals might take part to this complex pathway.

High glucose downregulates endothelial progenitor cell number via SIRT1.

Increasing evidence indicates that mammalian SIRT1 mediates calorie restriction and influences lifespan regulating a number of biological molecules such as FoxO1. SIRT1 controls the angiogenic activity of endothelial cells via deacetylation of FoxO1. Endothelial dysfunction and reduced new blood vessel growth in diabetes involve a decreased bioactivity of endothelial progenitor cells (EPCs) via repression of FoxO1 transcriptional activity. The relative contribution of SIRT1 with respect to the direct effects of high glucose on EPC number is poorly understood. We report that treatment of EPCs with high glucose for 3 days determined a consistent downregulation of EPC positive to DiLDL/lectin staining and, interestingly, this was associated with reduced SIRT1 expression levels and enzyme activity, and increased acetyl-FoxO1 expression levels. Moreover, EPCs responded to high glucose with major changes in the expression levels of cell metabolism-, cell cycle-, and oxidative stress-related genes or proteins. Proteomic analysis shows increased expression of nicotinamide phosphoribosyl transferase and mitochondrial superoxide dismutase whereas a glucose-related heat shock protein is reduced. These findings show that SIRT1 is a critical modulator of EPCs dysfunction during alteration of glucose metabolism.

Structure and Ligands Interactions of Citrus Tryptophan Decarboxylase by Molecular Modeling and Docking Simulations.

In a previous work, we in silico annotated protein sequences of Citrus genus plants as putative tryptophan decarboxylase (pTDC). Here, we investigated the structural properties of Citrus pTDCs by using the TDC sequence of Catharanthus roseus as an experimentally annotated reference to carry out comparative modeling and substrate docking analyses. The functional annotation as TDC was verified by combining 3D molecular modeling and docking simulations, evidencing the peculiarities and the structural similarities with C. roseus TDC. Docking with l-tryptophan as a ligand showed specificity of pTDC for this substrate. These combined results confirm our previous in silico annotation of the examined protein sequences of Citrus as TDC and provide support for TDC activity in this plant genus.

Effect of low doses of red wine and pure resveratrol on circulating endothelial progenitor cells.

Circulating endothelial progenitor cells (EPCs) play a significant role in neovascularization of ischaemic tissues and in re-endothelization of injured blood vessels. Identification of compounds able to enhance EPC levels and improve their functional activity, noticeably compromised by risk factors for coronary heart disease, is of clinical interest. This study evaluates the effects of red wine on EPCs. After being isolated from total peripheral blood mononuclear cells, EPC phenotype was confirmed by the presence of double positive cells for DiLDL uptake and lectin binding and by expression of CD34, CD133 and VE-cadherin cell surface markers. Long-term culture in the presence of red wine (1 microl/ml), containing resveratrol (Resv) at physiological concentration (nM), determined a time-dependent amelioration of cell number (P < 0.05). The presence of red wine prevented the TNF-alpha-induced reduction of EPC number (P < 0.05) and this effect was accompanied by reduced p38-phosphorylation expression levels (P < 0.05) and increased NOx levels (P < 0.05) Indeed, pure Resv alone significantly improved the TNF-alpha reduced EPC number (P < 0.05). This evidence indicates novel beneficial effects of red wine and Resv in the positive modulation of EPCs levels.

SIRT1 and SIRT6 Signaling Pathways in Cardiovascular Disease Protection.

SIGNIFICANCE: Oxidative stress represents the common hallmark of pathological conditions associated with cardiovascular disease (CVD), including atherosclerosis, heart failure, hypertension, aging, diabetes, and other vascular system-related diseases. The sirtuin (SIRT) family, comprising seven proteins (SIRT1-SIRT7) sharing a highly conserved nicotinamide adenine dinucleotide (NAD+)-binding catalytic domain, attracted a great attention for the past few years as stress adaptor and epigenetic enzymes involved in the cellular events controlling aging-related disorder, cancer, and CVD. Recent Advances: Among sirtuins, SIRT1 and SIRT6 are the best characterized for their protective roles against inflammation, vascular aging, heart disease, and atherosclerotic plaque development. This latest role has been only recently unveiled for SIRT6. Of interest, in recent years, complex signaling networks controlled by SIRT1 and SIRT6 common to stress resistance, vascular aging, and CVD have emerged. CRITICAL ISSUES: We provide a comprehensive overview of recent developments on the molecular signaling pathways controlled by SIRT1 and SIRT6, two post-translational modifiers proven to be valuable tools to dampen inflammation and oxidative stress at the cardiovascular level. FUTURE DIRECTIONS: A deeper understanding of the epigenetic mechanisms through which SIRT1 and SIRT6 act in the signalings responsible for onset and development CVD is a prime scientific endeavor of the upcoming years. Multiple "omic" technologies will have widespread implications in understanding such mechanisms, speeding up the achievement of selective and efficient pharmacological modulation of sirtuins for future applications in the prevention and treatment of CVD. Antioxid. Redox Signal. 28, 711-732.

The betaine profile of cereal flours unveils new and uncommon betaines.

We report the LC-ESI-MS/MS determination of betaines in commercial flours of cereals and pseudocereals most utilized in human nutrition. Results showed that glycine betaine, trigonelline, proline betaine, Nε-trimethyllysine were metabolites common to all examined flours, whereas an uncommon betaine, valine betaine, and glutamine betaine were present only in flours of barley, rye, oat, durum wheat, winter wheat, Triticum dicoccum and Triticum monococcum. Valine betaine and glutamine betaine, the latter never reported before in plants and animals, are not evenly distributed in the Poaceae family, but their presence or absence in flours depends on the subfamily to which the plant belongs. Interestingly, we also report for the first time the occurrence of pipecolic acid betaine (homostachydrine) and its precursor 1,2-N-methylpipecolic acid in rye flour. These two metabolites were not detected in any other cereal or pseudocereal flour, suggesting their potential role as markers of rye flour occurrence in cereal-based foods.

Ruminant meat and milk contain δ-valerobetaine, another precursor of trimethylamine N-oxide (TMAO) like γ-butyrobetaine.

Quaternary ammonium compounds containing N-trimethylamino moiety, such as choline derivatives and carnitine, abundant in meat and dairy products, are metabolic precursors of trimethylamine (TMA). A similar fate is reported for Nε-trimethyllysine and γ-butyrobetaine. With the aim at investigating the metabolic profile of such metabolites in most employed animal dietary sources, HPLC-ESI-MS/MS analyses on ruminant and non-ruminant milk and meat were performed. Results demonstrate, for the first time, the presence of δ-valerobetaine, occurring at levels higher than γ-butyrobetaine in all ruminant samples compared to non-ruminants. Demonstration of δ-valerobetaine metabolic origin, surprisingly, showed that it originates from rumen through the transformation of dietary Nε-trimethyllysine. These results highlight our previous findings showing the ubiquity of free Nε-trimethyllysine in vegetable kingdom. Furthermore, δ-valerobetaine, similarly to γ-butyrobetaine, can be degraded by host gut microbiota producing TMA, precursor of the proatherogenic trimethylamine N-oxide (TMAO), unveiling its possible role in the biosynthetic route of TMAO.

Carnitine Precursors and Short-Chain Acylcarnitines in Water Buffalo Milk.

Ruminants' milk contains δ-valerobetaine originating from rumen through the transformation of dietary Nε-trimethyllysine. Among ruminant's milk, the occurrence of δ-valerobetaine, along with carnitine precursors and metabolites, has not been investigated in buffalo milk, the second most worldwide consumed milk, well-known for its nutritional value. HPLC-ESI-MS/MS analyses of bulk milk revealed that the Italian Mediterranean buffalo milk contains δ-valerobetaine at levels higher than those in bovine milk. Importantly, we detected also γ-butyrobetaine, the l-carnitine precursor, never described so far in any milk. Of interest, buffalo milk shows higher levels of acetylcarnitine, propionylcarnitine, butyrylcarnitine, isobutyrylcarnitine, and 3-methylbutyrylcarnitine (isovalerylcarnitine) than cow milk. Moreover, buffalo milk shows isobutyrylcarnitine and butyrylcarnitine at a 1-to-1 molar ratio, while in cow's milk this ratio is 5 to 1. Results indicate a peculiar short-chain acylcarnitine profile characterizing buffalo milk, widening the current knowledge about its composition and nutritional value.