The Phytochemical Analysis of Vinca L. Species Leaf Extracts Is Correlated with the Antioxidant,Antibacterial, and Antitumor Effects

The phytochemical analysis of Vinca minor, V. herbacea, V. major, and V. major var. variegata leaf extracts showed species-dependent antioxidant, antibacterial, and cytotoxic effects correlated with the identified phytoconstituents. Vincamine was present in V. minor, V. major, and V. major var. variegata, while V. minor had the richest alkaloid content, followed by V. herbacea. V. major var. variegata was richest in flavonoids and the highest total phenolic content was found in V. herbacea which also had elevated levels of rutin. Consequently, V. herbacea had the highest antioxidant activity followed by V. major var. variegata. Whereas, the lowest one was of V. major. The V. minor extract showed the most efficient inhibitory effect against both Staphylococcus aureus and E. coli. On the other hand, V. herbacea had a good anti-bacterial potential only against S. aureus, which was most affected at morphological levels, as indicated by scanning electron microscopy. The Vinca extracts acted in a dose-depended manner against HaCaT keratinocytes and A375 melanoma cells and moreover, with effects on the ultrastructure, nitric oxide concentration, and lactate dehydrogenase release. Therefore, the Vinca species could be exploited further for the development of alternative treatments in bacterial infections or as anticancer adjuvants.     

In Silico Analysis and Functional Characterization of Antimicrobial and Insecticidal Vicilin from Moth Bean (Vigna aconitifolia (Jacq.) Marechal) Seeds

Vicilin has nutraceutical potential and different noteworthy medicative health-promoting biotic diversions, and it is remarkable against pathogenic microorganisms and insects. In this study, Vigna aconitifolia vicilin (VacV) has been identified and characterized from the seed of Vigna aconitifolia (Jacq.) Marechal (Moth beans). LC-MS/MS analysis of VacV provided seven random fragmented sequences comprising 238 residues, showing significant homology with already reported Vigna radiata vicilin (VraV). VacV was purified using ammonium sulfate precipitation (60%) followed by size exclusion chromatography on Hi-Load 16/60 Superdex 200 pg column and anion-exchange chromatography (Hi trap Q FF column). Purified VacV showed a major ~50 kDa band and multiple lower bands on 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under both reduced and non-reduced conditions. After all, a three-dimensional molecular structure of VacV was predicted, which showed β-sheeted molecular conformation similar to crystallographic structure of VraV. All Vicilins from V. aconitifolia and other plants were divided into six sub-groups by phylogenetic analysis, and VacV shared a high degree of similarity with vicilins of Vigna radiata, Pisum sativum, Lupinus albus, Cicer arietinum and Glycine max. Additionally, VacV (20 μg) has significant growth inhibition against different pathogenic bacteria along strong antifungal activity (50 μg). Likewise, VacV (3.0 mg) produced significant growth reduction in Rice Weevil Sitophilus oryzae larvae after 9 days compared with control. Furthermore, by using MMT assay, the cytotoxicity effect of VacV on the growth of HepG2 liver cancerous cells was tested. VacV showed cytotoxicity against the HepG-2 line and the acquired value was 180 µg after 48 h. Finally, we performed molecular docking against caspase-3 protein (PDB ID: 3DEI) for VacV bioactive receptor interface residues. Hence, our results reveal that VacV, has nutraceutical potential and moth beans can be used as a rich resource of functional foods.     

Quality Characteristics and Anthocyanin Profiles of Different Vitis amurensis Grape Cultivars and Hybrids from Chinese Germplasm

To evaluate the important Vitis amurensis germplasm, the quality characteristics and anthocyanin profiles of the ripe berries of 20 V. amurensis grapes and 11 interspecific hybrids in two consecutive years were analysed. Compared with the V. vinifera grapes, V. amurensis grapes had small berries with low total soluble solids and high titratable acids, and were richer in phenolic compounds except for flanan-3-ols in their skins but had lower phenolic contents in their seeds and showed lower antioxidant activities. An outstanding feature of the V. amurensis grapes was their abundant anthocyanin contents, which was 8.18-fold higher than the three wine grapes of V. vinifera. The anthocyanin composition of V. amurensis was characterized by an extremely high proportion of diglucoside anthocyanins (91.71%) and low acylated anthocyanins (0.04%). Interestingly, a new type of speculated 3,5,7-O-triglucoside anthocyanins was first identified and only detected in V. amurensis grapes and hybrids. Based on the total phenolic and anthocyanin characteristics, V. amurensis grapes were set apart from V. vinifera cultivars and the interspecific hybrids, for the same qualities, fell between them, as assessed by principal component analysis.     

The crystal structure of Ba2V2O7

Ba₂V₂O₇ is triclinic with a = 13.571(3), b = 7.320(2), c = 7.306(2) Å, α = 90.09(1), β = 99.48(1), β = 99.48(1), γ = 87.32(1)°, V = 7.15.1 ų, Z = 4, and space group $\text{P}\text{1}$. The crystal structure was solved by Patterson and Fourier methods and refined by full-matrix least-squares analysis to a R_w of 0.034 (R = 0.034) using 2484 reflections measured on a Syntex $\text{P}\text{1}$ automatic four-circle diffractometer. The structure has two unique divanadate groups that are repeated by the b and c lattice translations to form sheets of divanadate groups parallel to (100). These sheets are linked by four unique Ba atoms that lie between these sheets. Ba(1) and Ba(3) are coordinated by eight oxygens arranged in a distorted biaugmented triangular prism and a distorted cubic antiprism, respectively. Ba(2) is coordinated by 10 oxygens arranged in a distorted gyroelongated square dipyramid and Ba(4) is coordinated by nine oxygens arranged in a distorted triaugmented triangular prism. These coordination numbers are substantiated by a bond strength analysis of the structure, and the variation in 〈BaO〉 distances is compatible with the assigned cation and anion coordination numbers. Both divanadate groups are in the eclipsed configuraton with 〈VO(br)〉 bond lengths of 1.821(4) and 1.824(4) Å and VO(br)V angles of 125.6(3) and 123.7(3)°, respectively. Examination of the divanadate groups in a series of structures allows certain generalizations to be made. Longer 〈VO(br)〉 bond lengths are generally associated with smaller VO(br)V angles. When VO(br)V < 140°, the divanadate group is generally in an eclipsed configuration; when VO(br)V > 140°, the divanadate group is generally in a staggered configuration. Nontetrahedral cations with large coordination numbers require more oxygens with which to bond, and hence O(br) is more likely to be three coordinate, with the divanadate group in the eclipsed configuration. In the eclipsed configuration, decrease in VO(br)V promotes bonding between O(br) and nontetrahedral cations, and hence smaller nontetrahedral cations are generally associated with smaller VO(br)V angles.     

Espèces du genre vibrio associées aux produits marins du bassin d'arcachon

The distribution of Vibrio species in water and seafood collected from Arcachon Bay (located in the southwest of France) was studied. All invertebrate animals collected were associated with one or more Vibrio species. Eighty strains corresponding to 14 species were precisely identified. The identification of strains with V. parahaemolyticus was checked by DNA/DNA hybridization. The most frequently recovered species were V. alginolyticus, V. parahaemolyticus (non-haemolytic strains), V. harveyi and V. metschnikovii. The three V. cholerae non-O1 strains isolated from water and crab did not produce immunologically detectable cholera toxin and had no DNA fragment hybridizing with a cholera-toxin-gene-specific probe. It is suggested that the sanitary surveillance of seafood in France should include the precise characterization of potentially pathogenic Vibrio species.     

Enhancing the Thermostability of a Cold-Active Lipase from Penicillium cyclopium by In Silico Design of a Disulfide Bridge

Cysteine mutants of a cold-active lipase (PcLipI) from Penicillium cyclopium were designed by the software Disulfide by Design Ver. 1.20 in an effort to improve enzyme thermostability by addition of a disulfide bridge. Those mutants predicted by molecular dynamics simulation to have better thermostability than the wild type were first expressed in Escherichia coli BL21(DE3) and then, for further investigation, in Pichia pastoris GS115. By replacing Val²⁴⁸ and Thr²⁵¹ with cysteines to create a disulfide bridge, the recombinant lipases reE-PcLip^V248C-T251C (expressed in E. coli) and reP-PcLip^V248C-T251C (expressed in P. pastoris) were obtained. Both had enhanced thermostability with half-lives at 35 °C about 4.5- and 12.8-fold longer than that of the parent PcLipI expressed in E. coli and P. pastoris, respectively. The temperature optima of reE-PcLip^V248C-T251C and reP-PcLip^V248C-T251C were 35 and 30 °C, which were each 5 °C higher than those of the parent PcLipI expressed in E. coli and P. pastoris. The K _ms of reE-PcLip^V248C-T251C and reP-PcLip^V248C-T251C toward tributyrin were 53.2 and 39.5 mM, while their V _maxs were 1,460 and 3,800 U/mg, respectively. PcLip^V248C-T251C had better thermostability and catalytic efficiency than the other mutants and the parent PcLipI.     

Anthocyanin identification and composition of wild Vitis spp. accessions by using LC–MS and LC–NMR

The composition and concentration of anthocyanins of grape berry skins were analyzed in order to assess phenotypic variation between four grape wine varieties belonging to 4 different species: Vitis vinifera, Vitis amurensis, Vitis cinerea and Vitis X champinii. High-performance liquid chromatography coupled to mass spectrometry (LC–MS) and NMR spectroscopy (LC–NMR) were used to separate and identify the structure of anthocyanins present in these species. Combination of LC–MS and LC–NMR data resulted in the identification of 33 anthocyanins. In particular, newly reported cis isomers of p-coumaric-derivatives were identified (petunidin-, peonidin- and malvidin-3-(6-p-coumaroyl)-5-diglucoside). In V. cinerea and V. vinifera, anthocyanins were monoglucoside derivatives whereas in V. amurensis and V. X champinii, both mono- and diglucoside derivatives were identified. Malvidin-, delphinidin- and petunidin-derivatives were, respectively, the most abundant components in V. cinerea and V. vinifera, V. amurensis and V. X champinii.     

Study of anthocyanic profiles of twenty-one hybrid grape varieties by liquid chromatography and precursor-ion mass spectrometry

The anthocyanins of 21 hybrid red varieties produced by crossing V. vinifera, V. riparia, V. labrusca, V. lincecumii and V. rupestris species, the profiles for which have not yet been reported, were studied. Profiles were determined by LC/DAD, and identification of single anthocyanins was confirmed by LC/MS precursor-ion analysis. Anthocyanidin precursors (pelargonidin at m/z 271, dephinidin at m/z 303, cyanidin at m/z 287, petunidin at m/z 317, peonidin at m/z 301, and malvidin at m/z 331) and precursors of monoglucoside compounds allowed 24 different compounds to be identified. Analysis of precursor ions of monoglucoside anthocyanins at low capillary voltage revealed the signals of diglucosides only, providing a very selective method for analysis of diglucoside anthocyanins in grape. According to anthocyanin profile, the samples were subdivided into two groups: one characterized by the substantial presence of diglucoside compounds (particularly Seyve Villard 23-399 and Seyve Villard 23-369) and one by the scarce presence or practical absence of diglucosides (Seibel 10878, Burdin 4077, and Galibert 238-35). Particularly interesting for producing anthocyanin for the natural colorant industry were the varieties Siebel 8357, Bacò 30-12 and Terzi 100-31.     

Vibrational deactivation of DF

Rate constants for deactivation of DF in vibrational states n = 1 to 7 in collisions with DF (0) are calculated semiclassically in the temperature range from 300 K to 3000 K. The variation with the temperature agrees quite well with experiments for n = 1, although the theoretical rates are 30% lower than the experimental values for temperatures above 1200 K and 75% lower at 300 K. This difference is discussed. Single quantum transitions dominate. At 300 K the mechanism is predominantly a V—V transfer for n = 2 and a V-T/R transfer for n = 7, while both mechanisms contribute for n = 3–6. Collision complexes are important for both V—V and V-T/R energy transfer. Rotational relaxation times are calculated for HF and DF.     

A laser induced fluorescence study of vibrational energy transfer processes in cyclopropane

Results of infrared laser induced fluorescence studies on cyclopropane are presented. Molecules were excited from the ground state to the v₁₀ level of cyclopropane using a Q-switched CO₂ laser operating on either the P(14) or P(20) transition of the 9.6 μ branch. Fluorescence was observed from the v₆, v₈, v₁₀ + v₁₁ and v₅ + v₁₀ levels of cyclopropane. The self-deactivation of vibrationally excited cyclopropane through V → T/R processes was found to have a rate of 8.0 ± 1.5 ms^?1 torr^?1. Deactivation by rare gas collisions was also studied with comparison to simple V → T and V → R theories. V → V equilibration processes are discussed involving the v₆, v₈, v₁₀, v₁₁, and v₁₀ + v₁₁ levels.     

Radiation-induced reduction of vanadium(IV) to vanadium(II) in aqueous picolinate-formate solutions

Quantitative reduction of V(IV)(pic) to V(III)(pic)_n and then to V(II)(pic)_n(1 ⩽ n ⩽3) occurs when N₂O-saturated formate solutions (pH 4.2–6.3) containing V(IV) and picolinic acid (2-carboxypyridine) are irradiated. Pulse radiolysis measurements show that CO^-₂ reacts with picolinate only when the N-atom is protonated (k = 2.7 × 10⁸ dm³ mol^-1 s^-1). Reduction of V(IV)(pic) and V(III)(pic)_n is effected by the electron adduct of the protonated picolinate (picH)^. with rate constants at pH 4.2 of (3.5 ± 0.2) × 10⁷ dm³ mol^-1 s^-1 for V(IV)(pic) and (6.9 ± 0.4) × 10⁸ dm³ mol^-1 s^-1 for V(III)(pic)_n. No reduction of V(II)(pic)_n is observed.     

Extraction of antimony and tantalum from aqueous fluoride solutions by n-octanol and tributyl phosphate

¹⁹F and ²¹Sb NMR spectroscopy and chemical analysis were used to study the composition and structure of fluoride complexes of antimony(V) and tantalum(V) in organic and aqueous phases in extraction by tributyl phosphate (TBP) and n-octanol. It is found that extraction from solutions containing a single element or both elements occurs via the hydrate-solvate mechanism. The possibility of separating tantalum(V) and antimony(V) by extraction from fluoride solutions is shown. The efficiency of tantalum(V) and antimony(V) separation by extraction from fluoride solutions is enhanced at a transition from TBP to n-octanol.     

Location of energy barriers. VII. Sudden and gradual late-energy-barriers

In the earlier papers of this series it was noted that barriers of “type II” (“Late barriers”, associated with substantially endothermic reaction) exhibited a large cross section if a given reagent energy was present predominantly as vibration in the bond under attack. It was found, however, that it was advantageous to retain in the reagents an amount of translation sufficient to surmount that part of the endothermic energy barrier which lay in the coordinate of approach; this could be identified with the repulsive part of the energy-release in the reverse, exothermic, reaction. In the present 3D classical trajectory study we compare S_r(V′)_T′+V′, for two endothermic surfaces with almost identical barrier heights and late barrier-crest locations, but differing fractions of the barrier in the coordinate of approach. For the surface IIS with a “sudden” rise to the barrier crest (implying substantial attractive energy-release in the reverse direction), S_r(V′_T′+V′ increased continually with V′, despite very low T′. By contrast surface IIG with “gradual” rise to the barrier crest (highly repulsive in the reverse direction), exhibited an S_r(V′_T′+V′ that passed through a maximum. Two further surfaces were investigated; surface IIHS resembling IIS but with a substantially higher barrier, and surface I, IIG with an intermediate barrier-location and hence a large fraction of the barrier along the coordinate of approach. The dynamics exhibited S-type (sudden) behaviour on IIHS, and G-type (gradual) behaviour on I, IIG. The presence of a significant fraction of the barrier on G-type surfaces along the endothermic coordinate of approach correlated with a more gradual curvature of the repulsive wall. This is likely to contribute to the greater availability of translation for barrier-crossing on G-type surfaces. Increased reagent rotation, R′, increased the reactive cross-section for endothermic reaction; the indications are that the mechanism by which rotation is effective involves vibration-rotation interaction.     

Enantioselective O-acetylcyanation/cyanoformylation of aldehydes using catalysts with built-in crown ether-like motif in chiral macrocyclic V(V) salen complexes

Chiral macrocyclic V(V) salen complexes 1a-f derived from macrocyclic ligands obtained by the reaction of 1R,2R-(−) diaminocyclohexane/(1R,2R)-(+)-1,2-diphenylethylenediamine with bis-aldehydes 2 and 3 were synthesized and used as efficient catalysts in asymmetric cyanation reactions. The V(V) catalysts demonstrated excellent performance (product yields and ees up to 99%) with potassium cyanide (KCN) and sodium cyanide (NaCN). The catalytic system also performed very well with a safer source of cyanide-ethyl cyanoformate to give cyanohydrin carbonates in excellent yield and ee (up to 97%). The V(V) macrocyclic salen complex 1b retained its performance at multi-gram level and was conveniently recycled for a number of times.     

Anodic behavior of gold in acid thiourea solutions: A cyclic voltammetry and quartz microgravimetry study

It is shown that at potentials E < 0.5 V (NHE) gold undergoes practically no dissolution in thiourea solutions containing no catalytically active species. The dissolution at a perceptible rate (> 100 μA cm^?2) starts at E ≥ 0.65 V, with the primary process being the oxidation of thiourea, which gives rise a current peak at E ? 1.0 V. The thiourea oxidation at E ≥ 1.1 produces the appearance of catalytically active species, which drastically accelerate the gold dissolution process in the potential region extending from a steady-state value to 0.6 V, where the current efficiency for gold approaches 100% and a peak emerges at E ? 0.55 V. The peak’s height is commensurate with the value of the limiting diffusion current associated with the ligand supply. The species in question make no discernible impact on the thiourea oxidation process. Formamidine disulfide, which forms during the anodic oxidation of thiourea or which is added in solution on purpose, exerts no noticeable catalytic influence on the anodic gold dissolution. The catalytically active species is presumably the S^2? ion, product of decomposition and deep oxidation of thiourea and formamidine disulfide. Indeed, adding sulfide ions in solution has a strong catalytic effect on the gold dissolution, whose character is identical to that of the effect exerted by products of anodic oxidation of thiourea at E ≥ 1.1 V μA cm^?2.     

Nitrosative Stress Response in <Emphasis Type="Italic">Vibrio cholerae</Emphasis>: Role of <Emphasis Type="Italic">S</Emphasis>-Nitrosoglutathione Reductase

Vibrio cholerae, the causative agent of cholera, poses serious threats to humans worldwide. V. cholerae faces host inflammatory response and encounters nitrosative stress before establishing successful colonization. It is not clear how V. cholerae combats nitric oxide and reactive nitrogen species. In the present study, we used three clinical strains of V. cholerae and tested their nitrosative stress response pattern towards sodium nitroprusside (SNP) and S-Nitrosoglutathione (GSNO). Among them, V. cholerae, belonging to both O1 and O139 serotypes, showed moderate resistance to SNP and GSNO. However, a V. cholerae strain belonging to non O1 and non O139 showed sensitivity to SNP but resistance towards GSNO. Reduced glutathione and glutathione reductase play a significant role to combat nitrosative stress in V. cholerae. This is the first report where we show the presence of GSNO reductase activity in V. cholerae and that it plays an important role to detoxify S-Nitrosoglutathione. GSNO reductase activity of V. cholerae was regulated by posttranslational modification through S-nitrosylation under in vitro conditions which could be reversed by dithiothreitol (DTT). In addition, we show that biofilm formation remained unaffected under nitrosative stress in V. cholerae.     

Production of Polyhydroxyalkanoates (PHAs) by Vibrio alginolyticus Strains Isolated from Salt Fields

Vibrio alginolyticus is a halophilic organism usually found in marine environments. It has attracted attention as an opportunistic pathogen of aquatic animals and humans, but there are very few reports on polyhydroxyalkanoate (PHA) production using V. alginolyticus as the host. In this study, two V. alginolyticus strains, LHF01 and LHF02, isolated from water samples collected from salt fields were found to produce poly(3-hydroxybutyrate) (PHB) from a variety of sugars and organic acids. Glycerol was the best carbon source and yielded the highest PHB titer in both strains. Further optimization of the NaCl concentration and culture temperature improved the PHB titer from 1.87 to 5.08 g/L in V. alginolyticus LHF01. In addition, the use of propionate as a secondary carbon source resulted in the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). V. alginolyticus LHF01 may be a promising host for PHA production using cheap waste glycerol from biodiesel refining.     

Flow-injection spectrophotometry of vanadium by catalysis of the bromate oxidation of N,N'-bis(2-hydroxyl-3-sulfopropyl)-tolidine

A highly sensitive flow-injection method is proposed for the catalytic determination of vanadium(V) at sub-nanogram per milliliter levels using a new indicator reaction. The method is based on the catalytic effect of vanadium(V) on the bromate oxidation of N,N′-bis(2-hydroxyl-3-sulfopropyl)-tolidine. 1,2-Dihydroxybenzene-3,5-disulfonate was used as an activator in the vanadium(V)-catalyzed reaction and significantly enhanced the sensitivity of the method. Vanadium(V) in the range 0.01-3.0 ng ml⁻¹ was easily determined with sampling rate of about 30 h⁻¹. Vanadium(IV) could be also determined. The limit of detection (S/N=3) was 0.008 ng ml⁻¹ and the relative standard deviations were 1.4 and 1.6% for ten determinations of 0.2 ng ml⁻¹ vanadium(IV) and vanadium(V), respectively. Interferences from metal ions could be suppressed by the addition of ethylenediamine-N,N,N′,N′-tetrakis(methylenephosphonic acid) as a masking agent. The proposed method was successfully applied to the determination of vanadium in water samples.     

Locating redox couples in the layered sulfides with application to Cu[Cr2]S4

Use of LiPF₆ in EC:DEC as electrolyte has allowed electrochemical extraction of Li from LiV_1−yM_yS₂ and LiTi_1−yM_yS₂ (M=Cr or Fe). The data show access not only to the Ti(IV)/Ti(III) and V(IV)/V(III) redox couples, but also to the V(V)/V(IV) and Fe(III)/Fe(II) couples in these layered sulfides. However, the Cr(IV)/Cr(III) couple could not be accessed. The concept of redox-couple pinning is outlined and applied to the V(V)/V(IV) and Fe(III)/Fe(II) couples, which are pinned at the top of the S-3p bands. Holes associated with the “pinned” couples occupy orbitals of dominant S-3p character, but they have sufficient cation-3d character to prevent condensation of the holes into p-p antibonding states of disulfide bonds. Strong covalent bonding in the pinned couples creates itinerant-electron states in the partially occupied couples. Application to the metallic, ferromagnetic thiospinel Cu[Cr₂]S₄ favors location of the itinerant holes in states of a pinned Cu(II)/Cu(I) couple having primarily S-3p character.     

Metabolomic Profiling of Antioxidant Compounds in Five Vachellia Species

The genus Vachellia, previously known as Acacia, belongs to the family Fabaceae, subfamily Leguminosae, which are flowering plants, commonly known as thorn trees. They are traditionally used medicinally in various countries including South Africa for the treatment of ailments such as fever, sore throat, Tuberculosis, convulsions and as sedatives. The aim of this study was to determine biochemical variations in five Vachellia species and correlate their metabolite profiles to antioxidant activity using a chemometric approach. The antioxidant activity of five Vachellia aqueous-methanolic extracts were analyzed using three methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺) analysis and the ferric reducing antioxidant power (FRAP) assay by means of serial dilution and bioautography with the thin-layer chromatography (TLC) method. Amongst the Vachellia extracts tested, V. karroo, V. kosiensis and V. xanthophloea demonstrated the highest DPPH, ABTS⁺ and FRAP inhibitory activity. The antioxidant activities of DPPH were higher than those obtained by ABTS⁺, although these values varied among the Vachellia species. Proton nuclear magnetic resonance (¹H NMR), coupled with multivariate statistical modeling tools such as principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), were performed to profile metabolites responsible for the observed activity. The OPLS-DA categorized the five Vachellia species, separating them into two groups, with V. karroo, V. kosiensis and V. xanthophloea demonstrating significantly higher radical scavenging activity than V. tortilis and V. sieberiana, which clustered together to form another group with lower radical scavenging activity. Annotation of metabolites was carried out using the ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS), and it tentatively identified 23 metabolites of significance, including epigallocatechin (m/z = 305.0659), methyl gallate (m/z = 183.0294) and quercetin (m/z = 301.0358), amongst others. These results elucidated the metabolites that separated the Vachellia species from each other and demonstrated their possible free radical scavenging activities.