A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase.

Ligand-targeted drugs (LTDs) such as antibody-drug conjugates (ADCs) are currently attracting great attention as an alternative class of therapeutics to conventional chemotherapy for the clinical treatment of cancer. The linker is one of important factors determining the efficacy and toxicity of LTDs. The linker for LTDs should have enough stability during blood circulation, effectively release the payload, and leave no polar moieties in the released payload. However, the drug release activity and plasma stability of cleavable linkers are generally evaluated by complex and sophisticated in vivo techniques containing LC-MS, and the designing of new clinically applicable linkers remains a challenge. In this work, leucine aminopeptidase (LAP)-responsive fluorescent probes were designed as a simple preliminary model to verify whether a peptidase-responsive fluorescent probe can be used as a facile tool for the development of cleavable linkers although LAP is an exopeptidase and can't be a real target for cleavable linkers. LAP-responsive fluorescent probes were prepared by conjugation of a leucine to several xanthene fluorophores through a few linkages with a p-aminobenzyl spacer. The stability tests, kinetic study and live cell imaging of LAP-responsive activatable fluorescent probes demonstrated that the chemical stability and intrinsic activity of the linker for the release of drug can be easily evaluated by a fluorogenic assay. The ex vivo plasma stability test using mice suggested that an enzyme-responsive activatable fluorescent probe can be used as a feasible platform to evaluate the plasma stability of cleavable linkers during blood circulation.

Correction: A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase.

Correction for 'A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase' by Julie Kang et al., Analyst, 2022, https://doi.org/10.1039/d2an01145j.

Metabolomic analysis of amino acids and organic acids in aging mouse eyes using gas chromatography-tandem mass spectrometry.

This is a metabolomics study for monitoring altered amino acid (AA) and organic acid (OA) metabolism of in eyes from aging an mouse model at 8 and 18 weeks and 18 months. Simultaneous metabolic profiling analysis of OAs and AAs was performed as ethoxycarbonyl/methoxime/tert-butyldimethylsilyl derivatives by gas chromatography-tandem mass spectrometry. A total of 42 metabolites-24 AAs and 18 OAs-were determined and their composition values were normalized to the corresponding mean values of 8-week-old mice as the control group. Then their normalized values were plotted as star graphs, which were distorted and readily distinguishable for each age-related group. Among the 42 metabolites, 18 AAs and 11 OAs were age dependent and significantly different (p < 0.05). Principal component analysis and partial least squares discriminant analysis showed unclear separation between 8- and 18-week-old mice but clear separation between these and 18-month-old mice. In particular, the variable importance in projection scores of 4-hydroxyproline, cis-aconitic acid, glycine, isocitric acid, leucine, pipecolic acid and lysine from partial least-squares-discriminant analysis were higher than 1.3. A heatmap for the classification and visualization of 42 metabolites showed differences in metabolite changes with aging. Altered AA and OA profiles were monitored, which may explain the metabolic disturbance of AA and OA. These findings are related to mitochondrial dysfunctions related to energy metabolism and the impaired antioxidant system in the aging eye. Therefore, the present metabolomics results of the association between physiological states and altered metabolism of AA and OA will be useful for understanding the aging eye and related diseases.

Medicarpin and Homopterocarpin Isolated from Canavalia lineata as Potent and Competitive Reversible Inhibitors of Human Monoamine Oxidase-B.

Thirteen compounds were isolated from the Canavalia lineata pods and their inhibitory activities against human monoamine oxidase-A (hMAO-A) and -B (hMAO-B) were evaluated. Among them, compounds 8 (medicarpin) and 13 (homopterocarpin) showed potent inhibitory activity against hMAO-B (IC50 = 0.45 and 0.72 µM, respectively) with selectivity index (SI) values of 44.2 and 2.07, respectively. Most of the compounds weakly inhibited MAO-A, except 9 (prunetin) and 13. Compounds 8 and 13 were reversible competitive inhibitors against hMAO-B (Ki = 0.27 and 0.21 µM, respectively). Structurally, the 3-OH group at A-ring of 8 showed higher hMAO-B inhibitory activity than 3-OCH3 group at the A-ring of 13. However, the 9-OCH3 group at B-ring of 13 showed higher hMAO-B inhibitory activity than 8,9-methylenedioxygroup at the B-ring of 12 (pterocarpin). In cytotoxicity study, 8 and 13 showed non-toxicity to the normal (MDCK) and cancer (HL-60) cells and moderate toxicity to neuroblastoma (SH-SY5Y) cell. Molecular docking simulation revealed that the binding affinities of 8 and 13 for hMAO-B (-8.7 and -7.7 kcal/mol, respectively) were higher than those for hMAO-A (-3.4 and -7.1 kcal/mol, respectively). These findings suggest that compounds 8 and 13 be considered potent reversible hMAO-B inhibitors to be used for the treatment of neurological disorders.

Physcion-Matured Dendritic Cells Induce the Differentiation of Th1 Cells.

In addition to their use as colorants, anthraquinone derivatives have numerous medical applications, for example, as antibacterial and antiinflammatory agents. We confirmed that physcion (an anthraquinone derivative) induces TNF-alpha production by macrophages and increased the expressions of surface molecules (CD40, CD80, and CD86) and major histocompatibility complex (MHC) II. Based on these results, we hypothesized that physcion might induce the maturation of dendritic cells (DCs) to antigen-presenting cells (APCs), and decided to conduct in vitro experiments using bone-marrow-derived DCs (BMDCs). Physcion was not toxic to DCs and increased the expression of surface molecules (e.g., CD40, CD80, CD86, and MHC II) and the production of cytokines (e.g., IL-12p70, IL-1beta, IL-6, and TNF-alpha), but not of IL-10. To confirm that DCs matured by physcion induce T-cell-immune responses, naive CD4+ T cells were treated with physcion-treated DCs or their supernatants. Physcion induced the maturation of DCs, which promoted the polarization of Th1 cells. Our results show physcion-induced DC maturation via TLR4, and that mature DCs promote the differentiation of Th1 cells without affecting the differentiation of Th2 cells. These findings show that physcion has potential use as a treatment for inflammatory diseases associated with Th1/Th2 cell imbalance.

Atraric Acid Exhibits Anti-Inflammatory Effect in Lipopolysaccharide-Stimulated RAW264.7 Cells and Mouse Models.

Lichens, composite organisms resulting from the symbiotic association between the fungi and algae, produce a variety of secondary metabolites that exhibit pharmacological activities. This study aimed to investigate the anti-inflammatory activities of the secondary metabolite atraric acid produced by Heterodermia hypoleuca. The results confirmed that atraric acid could regulate induced pro-inflammatory cytokine, nitric oxide, prostaglandin E2, induced nitric oxide synthase and cyclooxygenase-2 enzyme expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Meanwhile, atraric acid downregulated the expression of phosphorylated IκB, extracellular signal-regulated kinases (ERK) and nuclear factor kappa B (NFκB) signaling pathway to exhibit anti-inflammatory effects in LPS-stimulated RAW264.7 cells. Based on these results, the anti-inflammatory effect of atraric acid during LPS-induced endotoxin shock in a mouse model was confirmed. In the atraric acid treated-group, cytokine production was decreased in the peritoneum and serum, and each organ damaged by LPS-stimulation was recovered. These results indicate that atraric acid has an anti-inflammatory effect, which may be the underlying molecular mechanism involved in the inactivation of the ERK/NFκB signaling pathway, demonstrating its potential therapeutic value for treating inflammatory diseases.

Metabolomic approaches to polyamines including acetylated derivatives in lung tissue of mice with asthma.

INTRODUCTION: Recently, the relationship between polyamine (PA) metabolism and asthma has been studied in severe asthmatic therapy, but systematic PA metabolism including their acetylated derivatives was not fully understood. OBJECTIVES: Profiling analysis of polyamines (PAs) was performed to understand the biochemical events and monitor altered PA metabolism in lung tissue of mice with asthma. METHODS: Polyamine profiling of lung tissue of mice with asthma was performed without derivatization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with star pattern recognition analysis. The PA levels between control and asthma groups were evaluated by multivariate analysis. RESULTS: In mouse lung tissue, seven PAs were determined by LC-MS/MS in multiple reaction monitoring (MRM) mode. Their levels were normalized to the corresponding mean levels of the control group for star pattern analysis, which showed distorted heptagonal shapes with characteristic and readily distinguishable patterns for each group. Levels of putrescine (p < 0.0034), N1-acetylputrescine (p < 0.0652), and N8-acetylspermidine (p < 0.0827) were significantly increased in asthmatic lung tissue. The separation of the two groups was evaluated using multivariate analysis. In unsupervised learning, acetylated PAs including N1-acetylspermine were the main metabolites for discrimination. In supervised learning, putrescine and N1-acetylputrescine were evaluated as important metabolites. CONCLUSIONS: The present results provide basic data for understanding polyamine metabolism in asthma and may help to improve the therapy for severe asthma patients.

Role of Th2 cytokines on the onset of asthma induced by meta-xylene in mice.

meta-Xylene (m-xylene) is one of three isomers of xylene, which is widely used as a solvent and detergent in various industries and medical technology. Exposure to volatile organic compounds, such as m-xylene, causes pulmonary inflammation and airway inflammation, thereby contributing to the onset of asthma. Exposure to m-xylene increases acute wheezing and intensity of asthma symptom. However, the mechanism of the onset of asthma by m-xylene has not been studied yet. C57BL/6 mice were sensitized and challenged by m-xylene at 100 or 300 mg/kg. The mice were then sacrificed after the last challenge. Exposure to m-xylene increased the total number of inflammatory cells and the production of interleukin (IL)-4, IL-5, IL-13, and immunoglobulin E related to the Th2 immune response. In contrast, the production of interferon-γ related to the Th1 immune response was decreased. In addition, the airway resistance increased according to the airway hyper-responsiveness measurements. Finally, a histological analysis revealed infiltration of inflammatory cells, mucus production, and lung fibrosis. These results suggest that m-xylene is a potential risk factor for asthma and the onset of asthma is caused by TH2 cytokines.

Asymmetric and Reduced Xanthene Fluorophores: Synthesis, Photochemical Properties, and Application to Activatable Fluorescent Probes for Detection of Nitroreductase.

Xanthene fluorophores, including fluorescein, rhodol, and rhodamines, are representative classes of fluorescent probes that have been applied in the detection and visualization of biomolecules. "Turn on" activatable fluorescent probes, that can be turned on in response to enzymatic reactions, have been developed and prepared to reduce the high background signal of "always-on" fluorescent probes. However, the development of activity-based fluorescent probes for biological applications, using simple xanthene dyes, is hampered by their inefficient synthetic methods and the difficulty of chemical modifications. We have, thus, developed a highly efficient, versatile synthetic route to developing chemically more stable reduced xanthene fluorophores, based on fluorescein, rhodol, and rhodamine via continuous Pd-catalyzed cross-coupling. Their fluorescent nature was evaluated by monitoring fluorescence with variation in the concentration, pH, and solvent. As an application to activatable fluorescent probe, nitroreductase (NTR)-responsive fluorescent probes were also developed using the reduced xanthene fluorophores, and their fluorogenic properties were evaluated.

The Protective Effects of 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-Glucoside in the OVA-Induced Asthma Mice Model.

Asthma is an inflammatory disease caused by an imbalance of Th1 and Th2 cells. In general, asthma is characterized by a stronger Th2 response. Most conventional asthma treatment focuses on improving airway flow or suppression of airway inflammation. To reduce the side effects of currently used asthma medicines, we have conducted studies on natural products that have no side effects. 2,3,5,4'-tetrahydroxystilbene-2-O-ß-d-glucoside (TSG), the main compound of Polygonum multiflorum (PM), has various biological activities, including anti-inflammation and anti-oxidation activities. However, the effect of TSG on asthma has not been studied yet. We examined the effects of TSG on Th2 immune responses using an OVA-induced asthma animal model. OVA-sensitized mice were treated with TSG. 24 h after the last intranasal challenge, airway hyperresponsiveness (AHR) was measured or serum and bronchoalveolar lavage fluid (BALF) were harvested. We measured typical Th1 and Th2 cytokines in serum and BALF. As a result, TSG suppressed Th2 responses, as shown by the lower levels of IL-4, IL-5, total IgE, OVA-specific IgE, and OVA-specific IgG1. On the other hand, TSG increased Th1 responses, as shown by the levels of IFN-gamma. Collectively, these results confirm the potential of TSG for asthma treatment through modulation of inflammatory responses. Considering that the cytotoxic effect of PM extract is due to the cis isomer of TSG, if the effect of TSG on asthma treatment is found to be non-toxic in clinical trials, it would be more effective to use it as a purified component than PM extract as an asthma treatment agent.

Protective Effects of 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside on Ovariectomy Induced Osteoporosis Mouse Model.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside (TSG), an active polyphenolic component of Polygonum multiflorum, exhibits many pharmacological activities including antioxidant, anti-inflammation, and anti-aging effects. A previous study demonstrated that TSG protected MC3T3-E1 cells from hydrogen peroxide (H2O2) induced cell damage and the inhibition of osteoblastic differentiation. However, no studies have investigated the prevention of ovariectomy-induced bone loss in mice. Therefore, we investigated the effects of TSG on bone loss in ovariectomized mice (OVX). Treatment with TSG (1 and 3 µg/g; i.p.) for six weeks positively affected body weight, uterine weight, organ weight, bone length, and weight change because of estrogen deficiency. The levels of the serum biochemical markers of calcium (Ca), inorganic phosphorus (IP), alkaline phosphatase (ALP), and total cholesterol (TCHO) decreased in the TSG-treated mice when compared with the OVX mice. Additionally, the serum bone alkaline phosphatase (BALP) levels in the TSG-treated OVX mice were significantly increased compared with the OVX mice, while the tartrate-resistant acid phosphatase (TRAP) activity was significantly reduced. Furthermore, the OVX mice treated with TSG showed a significantly reduced bone loss compared to the untreated OVX mice upon micro-computed tomography (CT) analysis. Consequently, bone destruction in osteoporotic mice as a result of ovariectomy was inhibited by the administration of TSG. These findings indicate that TSG effectively prevents bone loss in OVX mice; therefore, it can be considered as a potential therapeutic for the treatment of postmenopausal osteoporosis.

Suppression Effect of Astaxanthin on Osteoclast Formation In Vitro and Bone Loss In Vivo.

Osteoporosis is characterized by a reduction of the bone mineral density (BMD) and microarchitectural deterioration of the bone, which lead to bone fragility and susceptibility to fracture. Astaxanthin (AST) has a variety of biological activities, such as a protective effect against asthma or neuroinflammation, antioxidant effect, and decrease of the osteoclast number in the right mandibles in the periodontitis model. Although treatment with AST is known to have an effect on inflammation, no studies on the effect of AST exposure on bone loss have been performed. Thus, in the present study, we examined the antiosteoporotic effect of AST on bone mass in ovariectomized (OVX) mice and its possible mechanism of action. The administration of AST (5, 10 mg/kg) for 6 weeks suppressed the enhancement of serum calcium, inorganic phosphorus, alkaline phosphatase, total cholesterol, and tartrate-resistant acid phosphatase (TRAP) activity. The bone mineral density (BMD) and bone microarchitecture of the trabecular bone in the tibia and femur were recovered by AST exposure. Moreover, in the in vitro experiment, we demonstrated that AST inhibits osteoclast formation through the expression of the nuclear factor of activated T cells (NFAT) c1, dendritic cell-specific transmembrane protein (DC-STAMP), TRAP, and cathepsin K without any cytotoxic effects on bone marrow-derived macrophages (BMMs). Therefore, we suggest that AST may have therapeutic potential for the treatment of postmenopausal osteoporosis.

Effects of diisononyl phthalate on osteopenia in intact mice.

Osteopenia is characterized by bone loss and deterioration of trabecular bone, which leads to osteoporotic fractures. This disease is highly prevalent in industrialized areas and is associated with exposure to endocrine disrupting chemicals (EDCs). Diisononyl phthalate (DINP) is one of these EDCs and is mainly used as a plasticizer in flexible polyvinyl chloride (PVC) products. Although it is well known that exposure to DINP is harmful to humans, no studies have been reported concerning its contribution to osteopenia. Therefore, in this study, we injected DINP (2, 20, and 200mg/kg) into C3H/HeN mice for 6weeks and found that the uterus weight, bone (femur and tibia) weight, and bone length of the DINP-exposed mice were reduced compared to those of the SHAM group. On the other hand, body weight, the serum alkaline phosphatase (ALP) and inorganic phosphorus (IP) levels in the DINP treated mice were increased compared with those of the SHAM group. The tartrate-resistant acid phosphatase (TRAP) activity (bone resorption marker) was increased and the bone alkaline phosphatase (BALP) activity was lowered by the treatment with DINP as compared with the SHAM group. Furthermore, the microarchitecture of the femur and tibia in the intact mice was destroyed by the DINP injection. The tissue volume (TV), bone volume (BV), BV/TV, bone surface (BS), BS/TV, trabecular thickness (Tb.Th), and trabecular number (Tb.N) were reduced and the trabecular pattern factor (Tb.Pf), structure model index (SMI), and trabecular separation (Tb.Sp) were increased by the DINP injection. The bone mineral density (BMD) of the femur and tibia was lower in the DINP group than in the SHAM group. These results indicate that DINP contributes to an increased risk of osteopenia via destruction of the microarchitecture and enhancement of osteoclast activity.

Saccharomonopyrones A-C, New α-Pyrones from a Marine Sediment-Derived Bacterium Saccharomonospora sp. CNQ-490.

Intensive study of the organic extract of the marine-derived bacterium Saccharomonospora sp. CNQ-490 has yielded three new α-pyrones, saccharomonopyrones A-C (1-3). The chemical structures of these compounds were assigned from the interpretation of 1D, 2D NMR and mass spectrometry data. Saccharomonopyrone A (1) is the first α-pyrone microbial natural product bearing the ethyl-butyl ether chain in the molecule, while saccharomonopyrones B and C possess unusual 3-methyl and a 6-alkyl side-chain within a 3,4,5,6-tetrasubstituted α-pyrone moiety. Saccharomonopyrone A exhibited weak antioxidant activity using a cation radical scavenging activity assay with an IC50 value of 140 µM.

The Protective Effects of Astaxanthin on the OVA-Induced Asthma Mice Model.

Although astaxanthin has a variety of biological activities such as anti-oxidant effects, inhibitory effects on skin deterioration and anti-inflammatory effects, its effect on asthma has not been studied. In this paper, the inhibitory effect of astaxanthin on airway inflammation in a mouse model of ovalbumin (OVA)-induced asthma was investigated. We evaluated the number of total cells, Th1/2 mediated inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and airway hyperresponsiveness as well as histological structure. The level of total IgE, IgG1, IgG2a, OVA-specific IgG1, and OVA-specific IgG2a were also examined. The oral administration of 50 mg/mL astaxanthin inhibited the respiratory system resistance, elastance, newtonian resistance, tissue damping, and tissue elastance. Also, astaxanthin suppressed the total cell number, IL-4, and IL-5, and increased the IFN-γ in the BALF. In the sera, total IgE, IgG1, and OVA-specific IgG1 were reduced by astaxanthin exposure and IgG2a and OVA-specific IgG2a were enhanced via oral administration of astaxanthin. Infiltration of inflammatory cells in the lung, production of mucus, lung fibrosis, and expression of caspase-1 or caspase-3 were suppressed in OVA-induced asthmatic animal treated with astaxanthin. These results suggest that astaxanthin may have therapeutic potential for treating asthma via inhibiting Th2-mediated cytokine and enhancing Th1-mediated cytokine.

Anti-adipogenic and anti-diabetic effects of cis-3',4'-diisovalerylkhellactone isolated from Peucedanum japonicum Thunb leaves in vitro.

Peucedanum japonicum Thunb is a medicinal plant belonging to the family Umbelliferae. This study evaluated the anti-diabetic and anti-obesity effects of cis-3',4'-diisovalerylkhellactone (cDIVK) isolated from Peucedanum japonicum Thunb leaves. cDIVK (30 and 50µM) effectively inhibited adipocyte differentiation and fat accumulation, whereas it stimulated glucose uptake compared with the control in 3T3-L1 cells. cDIVK significantly increased AMPK activation and suppressed protein and mRNA expression of major adipogenic transcriptional factors such as C/EBPα, PPARγ and SREBP-1c in 3T3-L1 cells. In addition, cDIVK had potential α-glucosidase inhibitory activity. These results indicated that cDIVK may act as a natural dual therapeutic agent for diabetes and obesity.

Herbal preparation (HemoHIM) enhanced functional maturation of bone marrow-derived dendritic cells mediated toll-like receptor 4.

BACKGROUND: HemoHIM, which is an herbal preparation of three edible herbs (Angelicam gigas Nakai, Cnidium offinale Makino, and Peaonia japonica Miyabe), is known to have various biological and immunological activities, but the modulatory effects of this preparation on dendritic cells (DCs)-mediated immune responses have not been examined previously. DCs are a unique group of white blood cells that initiate primary immune responses by capturing, processing, and presenting antigens to T cells. RESULTS: In the present study, we investigated the effect of HemoHIM on the functional and phenotypic maturation of murine bone marrow-derived dendritic cells (BMDCs) both in vitro and in vivo. The expression of co-stimulatory molecules (CD40, CD80, CD86, MHC I, and MHC II) and the production of cytokines (IL-1ß, IL-6, IL-12p70, and TNF-α) were increased by HemoHIM in BMDCs. Furthermore, the antigen-uptake ability of BMDCs was decreased by HemoHIM, and the antigen-presenting ability of HemoHIM-treated mature BMDCs increased TLR4-dependent CD4(+) and CD8(+) T cell responses. CONCLUSIONS: Our findings demonstrated that HemoHIM induces TLR4-mediated BMDCs functional and phenotypic maturation through in vivo and in vitro. And our study showed the antigen-presenting ability that HemoHIM-treated mature BMDCs increase CD4(+) and CD8(+) T cell responses by in vitro. These results suggest that HemoHIM has the potential to mediate DC immune responses.

The Protective Effects of Alisol A 24-Acetate from Alisma canaliculatum on Ovariectomy Induced Bone Loss in Vivo.

Alisma canaliculatum is a herb commonly used in traditional Korean medicine, and has been shown in scientific studies to have antitumor, diuretic hepatoprotective, and antibacterial effects. Recently, the anti-osteoclastogenesis of alisol A 24-acetate from Alisma canaliculatum was investigated in vitro. However, the influence of alisol A 24-acetate on osteoporosis in animals has not been investigated. The present study was undertaken to investigate the anti-osteoporotic effect of alisol A 24-acetate on bone mass in ovariectomized (OVX) mice and to identify the mechanism responsible for its effects. OVX mice were treated daily with 0.5 or 2 µg/g of alisol A 24-acetate for a period of six weeks. It was found that these administrations significantly suppressed osteoporosis in OVX mice and improved bone morphometric parameters. The serum estradiol, bone alkaline phosphatase levels, regulatory T/Th17 cell numbers were significantly increased by alisol A 24-acetate as compared with untreated OVX mice. In addition, TRAP activity was inhibited by alisol A 24-acetate in OVX mice. These results suggest alisol A 24-acetate effectively prevents bone loss in OVX mice, and that it can be considered a potential therapeutic for the treatment of postmenopausal osteoporosis.

Production of novel vinegar having antioxidant and anti-fatigue activities from Salicornia herbacea L.

BACKGROUND: Salicornia herbacea L. is a halophyte that grows in salt marshes and contains significant amounts of salts and minerals. Because it is known as a folk medication to treat diseases, various processed products such as powder, globular type of powder, laver and extract have been developed. However, it is difficult to process as a drink because of its high salinity. In the present study, glasswort vinegar (GV) containing high amounts of organic acids and minerals was developed via two-step fermentation with unpolished rice substrates and investigated its antioxidant and anti-fatigue activities. RESULTS: GV showed various free radical scavenging effects, reducing power, oxidized-LDL inhibition and superoxide dismutase-like activities. Compared with the control group (orally administered 7 g kg(-1) distilled water), the GV supplementation group showed increased running endurance and had higher glycogen accumulation in liver and muscles of rats exhausted by exercise. Furthermore, the GV-administered group demonstrated significantly elevated lactate and ATP metabolism, promoting enzyme activities such as muscle creatine kinase and lactate dehydrogenase, whereas serum fatigue biomarkers such as ammonia, lactate and inorganic acid were markedly decreased. CONCLUSION: These results indicate that GV can be used as a functional food for the development of a dietary beverage to alleviate fatigue.

Simultaneous analysis of seven 2-hydroxy fatty acids as tert-butyldimethylsilyl derivatives in plasma by gas chromatography-mass spectrometry.

An efficient method for the simultaneous analysis of seven 2-hydroxy fatty acids (2-HFAs) as tert-butyldimethylsilyl (TBDMS) derivative was developed by gas chromatography-mass spectrometry in selected ion monitoring mode. New mass spectral data on 2-hydroxycapric, 2-hydroxypalmitic, 2-hydroxystearic and 2-hydroxybehenic acids as di-TBDMS derivatives for hydroxyl and carboxyl groups were built. Under the optimal conditions, the present method showed a good correlation coefficient (r ≥ 0.999) in the range of 0.01-0.5 µg. The precision showed low relative standard deviation of <10%, and the accuracy (percentage relative error) varied from -5.2 to 0.3 for the seven 2-HFAs studied. Recovery rates of all 2-HFAs were ≥ 93.2% with good precision. When applied to normal human plasma, seven 2-HFAs were positively identified. Therefore, the present efficient method will be useful for simultaneous analysis of 2-HFAs in plasma.