Effects of resection volume on postoperative micturition symptoms and retreatment after transurethral resection of the prostate.

PURPOSE: Despite advances in technology, such as advent of laser enucleation and minimally invasive surgical therapies, transurethral resection of the prostate (TURP) remains the most widely performed surgical technique for benign prostatic hyperplasia (BPH). We evaluated resection volume (RV)-derived parameters and analyzed the effect of RV on post-TURP outcomes. METHODS: This observational study used data from patients who underwent TURP at two institutions between January 2011 and December 2021 Data from patients with previous BPH surgical treatment, incomplete data, and underlying disease affecting voiding function were excluded. The collected data included age, prostate-specific antigen, transrectal ultrasound (TRUS)- and uroflowmetry-derived parameters, RV, perioperative laboratory values, perioperative International Prostatic Symptom Score (IPSS), follow-up period, retreatment requirements and interval between the first TURP and retreatment. RESULTS: In 268 patients without prior BPH medication, there were no differences in prostate volume (PV), transitional zone volume (TZV), or RV according to IPSS. A total of 60 patients started retreatment, including medical or surgical treatment, within the follow-up period. There was a significant difference in RV/PV between the groups without and with retreatment respectively (0.56 and 0.37; p = 0.008). However, preoperative TRUS- and uroflowmetry-derived parameters did not differ between the two groups. Multiple linear regression analysis showed that RV (p = 0.003) and RV/TZV (p = 0.006) were significantly associated with differences in perioperative IPSS. In the multivariate logistic regression analysis, only RV/PV was correlated with retreatment (p = 0.010). CONCLUSION: Maximal TURP leads to improved postoperative outcomes and reduced retreatment rate, it may gradually become a requirement rather than an option.

Does the Time Interval from Biopsy to Radical Prostatectomy Affect the Postoperative Oncologic Outcomes in Korean Men?

BACKGROUND: Prostate cancer (PC) is the second most common type of cancer in men worldwide and the fifth most common cancer among Korean men. Although most PCs grow slowly, it is unclear whether a longer time interval from diagnosis to treatment causes worse outcomes. This study aimed to investigate whether the time interval from diagnosis to radical prostatectomy (RP) in men with clinically localized PC affects postoperative oncologic outcomes. METHODS: We retrospectively analyzed data of 427 men who underwent RP for localized PC between January 2005 and June 2016. The patients were divided into two groups based on the cutoff median time interval (100 days) from biopsy to surgery. The associations between time interval from biopsy to surgery (< 100 vs. ≥ 100 days) and adverse pathologic outcomes such as positive surgical margin, pathologic upgrading, and upstaging were evaluated. Biochemical recurrence (BCR)-free survival rates were analyzed and compared based on the time interval from biopsy to surgery. RESULTS: Pathologic upgrading of Gleason score in surgical specimens was more frequent in the longer time interval group and showed marginal significance (38.8% vs. 30.0%; P = 0.057). Based on multivariable analysis, an association was observed between time interval from biopsy to surgery and pathologic upgrading (odds ratio, 2.211; 95% confidence interval [CI], 1.342-3.645; P = 0.002). BCR-free survival did not differ based on time interval from biopsy to surgery, and significant association was not observed between time interval from biopsy to surgery and BCR on multivariable analysis (hazard ratio, 1.285; 95% CI, 0.795-2.077; P = 0.305). CONCLUSION: Time interval ≥ 100 days from biopsy to RP in clinically localized PC increased the risk of pathologic upgrading but did not affect long-term BCR-free survival rates in Korean men.

Decolorization of textile dyes in an air-lift bioreactor inoculated with Bjerkandera adusta OBR105.

A new decolorizing white-rot fungus, OBR105, was isolated from Mount Odae in South Korea and identified by the morphological characterization of its fruit body and spores and partial 18s rDNA sequences. The ligninolytic enzyme activity of OBR105 was studied to characterize their decolorizing mechanism using a spectrophotometric enzyme assay. For the evaluation of the decolorization capacity of OBR105, the isolate was incubated in an erlenmeyer flask and in an airlifte bioreator with potato dextrose broth (PDB) medium supplemented with each dye. In addition, the decolorization efficiency of real textile wastewater was evaluated in an airlift bioreactor inoculated with the isolate. The isolate was identified as Bjerkandera adusta and had ligninolytic enzymes such as laccase, lignin peroxidase (LiP), and Mn-dependent peroxidase (MnP). Its LiP activity was higher than its MnP and laccase activities. B. adusta OBR105 successfully decolorized reactive dyes (red 120, blue 4, orange 16, and black 5) and acid dyes (red 114, blue 62, orange 7, and black 172). B. adusta OBR105 decolorized 91-99% of 200 mg L-1 of each dye (except acid orange 7) within 3 days in a PDB medium at 28°C, pH 5, and 150 rpm. This fungus decolorized only 45% of 200 mg L-1 acid orange 7 (single azo-type dye) within 3 days, and the decolorization efficiency did not increase by prolonging the cultivation time. In the air-lift bioreactor, B. adusta OBR105 displayed a high decolorization capacity, greater than 90%, for 3 acid dyes (red 114, blue 62, and black 172) and 1 reactive dye (blue 4) within 10-15 h of treatment. B. adusta OBR105 could decolorize real textile wastewater in the air-lift bioreactor. This result suggests that an air-lift reactor employing B. adusta OBR105 is a promising bioreactor for the treatment of dye wastewater.

Decolorization of acid, disperse and reactive dyes by Trametes versicolor CBR43.

The mycoremediation has been considered as a promising method for decolorizing dye wastewater. To explore new bioresource for mycoremediation, a new white-rot fungus that could decolorize various dyes commonly used in textile industries was isolated, and its ligninolytic enzyme activity and decolorization capacity were characterized. The isolated CBR43 was identified as Trametes versicolor based on the morphological properties of its fruit body and spores, as well as through partial 18S rDNA gene sequences. Isolated CBR43 displayed high activities of laccase and Mn-dependent peroxidase, whereas its lignin peroxidase activity was relatively low. These ligninolytic enzyme activities in potato dextrose broth (PDB) medium were enhanced by the addition of yeast extract (1-10 g L-1). In particular, lignin peroxidase activity was increased more than 5 times in the PDB medium amended with 10 g L-1 of yeast extract. The CBR43 decolorized more than 90% of 200 mg L-1 acid dyes (red 114, blue 62 and black 172) and reactive dyes (red 120, blue 4, orange 16 and black 5) within 6 days in the PDB medium. CBR43 decolorized 67% of 200 mg L-1 acid orange 7 within 9 days. The decolorization efficiencies for disperse dyes (red 1, orange 3 and black 1) were 51-80% within 9 days. The CBR43 could effectively decolorize high concentrations of acid blue 62 and acid black 172 (500-700 mg L-1). The maximum dye decolorization rate was obtained at 28°C, pH 5, and 150 rpm in the PDB medium. T. versicolor CBR43 had high laccase and Mn-dependent peroxidase activities, and could decolorize a wide variety of dyes such as acid, disperse and reactive textile dyes. This fungus had decolorizing activities of azo-type dyes as well as anthraquinone-type dyes. T. versicolor CBR43 is one of promising bioresources for the decolorization of textile wastewater including various dyes.

Classification of ginseng berry (Panax ginseng C.A. MEYER) extract using 1H NMR spectroscopy and its inhibition of lipid accumulation in 3 T3-L1 cells.

BACKGROUND: Panax ginseng is a famous traditional medicine in Korea for its beneficial effect on obesity, cardiac and liver associated diseases. The aim of this study was to investigate the metabolite in Panax ginseng (P. ginseng, Aralicaceae) berries depending on the ripen stages and evaluate its potential inhibition on adipocyte differentiation in 3 T3-L1 cells. METHODS: Different ripening stage samples of P. ginseng berry were analyzed through global metabolite profiling by NMR spectroscopy. Lipid accumulation in the cells was analyzed by Oil Red O staining. RESULTS: The PLS-DA clearly distinguished P. ginseng berry extract (PGBE) according to the partial ripe (PR), ripe(R) and fully ripe (FR) stage. Lipid accumulation of PGBE was examined by measuring triglyceride content and Oil-Red O staining. These results suggested that the FR stage of PGBE decrease in lipid accumulation during adipocyte differentiation and the amount of threonine, asparagine, fumarate, tyraine, tyrosine, and phenylalanine increased with longer ripening of ginseng berries. CONCLUSION: Metabolite profiling of P. ginseng was identified by 1H NMR spectra. P. ginseng extract efficiently inhibits adipogenesis in 3 T3-L1 adipocytes concluded that the P. ginseng has the antiobesity properties.

Korean sexually transmitted infection guidelines 2023 revision, guideline update of viral infections: Genital herpes and anogenital warts.

The Korean Association of Urogenital Tract Infection and Inflammation and the Korea Disease Control and Prevention Agency regularly update, revise, and develop new content for the Korean sexually transmitted infection (STI) guidelines. These professional bodies respond to changing epidemiological trends and evolving scientific evidence, and consider advances in laboratory diagnostics and research. The principal recommendations of the 2023 Korean STI guidelines in terms of viral infection follow: 1) If genital herpes recurs more than 4-6 times annually, suppressive therapy with acyclovir 400 mg orally 2 times/day or famciclovir 250 mg orally 2 times/day or valacyclovir 500 mg orally once a day (for patients with <10 episodes/year) or valacyclovir 1 g orally once daily (for patients with ≥10 episodes/year) is recommended to prevent recurrence; 2) molecular human papillomavirus (HPV) testing is not recommended as a routine test for STI status, nor for determination of HPV vaccination status; and 3) patients should inform their current sexual partners about anogenital warts because the types of HPV that cause such warts can be passed to partners. These guidelines will be updated every 5 years and will be revised when new knowledge on STIs becomes available and there is a reasonable need to improve the guidelines. Physicians and other healthcare providers can use the guidelines to assist in the prevention and treatment of STIs.

Simple preparative gas chromatographic method for isolation of menthol and menthone from peppermint oil, with quantitative GC-MS and (1) H NMR assay.

The quantitative performance of a simple home-built preparative gas chromatography (prep-GC) arrangement was tested, incorporating a micro-fluidic Deans switch, with collection of the target compound in a deactivated uncoated capillary tube. Repeat injections of a standard solution and peppermint sample were made into the prep-GC instrument. Individual compounds were eluted from the trapping capillary, and made up to constant volume. Chloronaphthalene internal standard was added in some cases. Recovered samples were quantitatively assayed by using GC-MS. Calibration linearity of GC-MS for menthol standard area response against number of injections (2-20 repeat injections) was excellent, giving R(2) of 0.996. For peppermint, menthol correlation over 2-20 repeated injections was 0.998 for menthol area ratio (versus IS) data. Menthone calibration for peppermint gave an R(2) of 0.972. (1) H NMR spectroscopy was conducted on both menthol and menthone. Good correspondence with reference spectra was obtained. About 80 µg of isolated menthol and menthone solute was collected over a sequence of 80 repeat injections from the peppermint sample, as assayed by 600 MHz (1) H NMR analysis (∼100% recovery for menthol from peppermint). A procedure is proposed for prediction of number of injections required to acquire sufficient material for NMR detection.

Changes in the Physicochemical Properties, Antioxidant Activity and Metabolite Analysis of Black Elephant Garlic (Allium ampeloprasum L.) during Aging Period.

This study investigated the effects of the aging period on the black elephant garlic (Allium ampeloprasum L.) manufacturing process. Black elephant garlic is a processed elephant garlic product prepared by high-temperature and high-humidity treatment for 40 days. The proximate composition (moisture, crude lipid, crude protein, carbohydrate, and ash), minerals, color values, reducing sugars, pH, total polyphenol contents, total flavonoid contents and antioxidant activities of elephant garlic and black elephant garlic were evaluated. The browning intensity of elephant garlic increased with the aging period, but the browning reaction terminated after aging for 30 days, exhibiting the same browning level. Reducing sugars increased over the aging period until 20 days, and then decreased with the aging period, in contrast to the pH, which decreased from 6.47 to 3.68 over the aging period. Antioxidant components, including the total polyphenol and total flavonoid contents of black elephant garlic, increased significantly until day 30 of aging. From the metabolite profiles determined through GC/MS analysis, it was confirmed that primary metabolites related to antioxidant components, such as lactic acid and 5-hydroxymethyl-2-furoic acid, were generated during the aging process of elephant garlic.

Metabolite profiling of a Sargassum micracanthum methanol extract with in vitro efficacy against human head and neck squamous cell carcinoma aggressiveness.

OBJECTIVE: Extracts from the brown algae Sargassum micracanthum have documented anti-viral, anti-oxidant, and anti-inflammatory activities as well as potential anti-tumor efficacy against several cancer types. Here, we evaluated the inhibitory effect and molecular mechanisms of methanol extract of S. micracanthum (MESM) on the aggressiveness of human head and neck squamous cell carcinoma (HNSCC) using in vitro cell culture-based models. DESIGN: To test the potential efficacy of MESM on the migratory and invasive properties of HNSCC cells, we used wound healing, transwell cell migration and invasion assays. Proteome profiling and functional in silico analysis were applied to investigate the possible modes of action by MESM. We also examined the metabolite profiling of MESM using gas chromatography/mass spectrometry. RESULTS: MESM inhibited the motility of human HNSCC cell lines as well as invasiveness without influencing cell survival. Proteome profiling identified 19 oncogenic proteins significantly downregulated by MESM treatment. Protein-protein interaction network and gene ontology analyses revealed that Tie2 and associated angiogenic signaling pathway components were significantly enriched among these downregulated oncogenic proteins, which was confirmed by validating the reduced Tie2 expression in MESM treatment groups. Metabolite profiling of MESM identified six-carbon sugar alcohols such as D-sorbitol and/or D-mannitol as the main bioactive compounds. D-sorbitol and D-mannitol effectively reduced Tie2 expression and the aggressiveness of human HNSCC cell lines. CONCLUSIONS: These findings suggest that six-carbon sugar alcohols in MESM have promising anti-cancer efficacy for the treatment of human HNSCC and further identify Tie2 signaling components as potential treatment targets.

Nutritional composition and phytochemical screening in different parts of Hibiscus syriacus L.

As the national flower of Korea, the Hibiscus syriacus L. (Rose of Sharon) is symbolic in its abundance and is a prominent feature of Korean culture. H. syriacus has played an important role in Korea, not only as an ornamental plant but also as an essential ingredient in folk remedies through its various parts. This study aimed to characterize the nutritional and biochemical composition of each plant unit of H. syriacus "Wonhwa." The units are namely: the petals, leaves, roots, and sprouts from its seeds. According to the results each unit produced, the sprouts had the highest content of amino acids and fatty acids which adhere to the requirements of nutritionally excellent food ingredients. The petals produced high quantities of glucose, sucrose, and fumaric acid, with the highest antioxidant activity among the four units. The main bioactive compounds detected in H. syriacus extracts in the four units were o-coumaric acid, p-coumaric acid, schaftoside, isoschaftoside, apigenin-6-C-glucoside-7-o-glucoside, and kaempferol-3-O-galactoside-7-O-rhamnoside. Overall, the highest number of bioactive compounds, 2 phenolic acids and 22 flavonoids, were identified in the petals. These results suggest the possibility of excellent pharmacological activity in the petals.

Chemical changes and antioxidant activities of heated whole barley extracts.

Chemical profiles of ethanolic (70%) and aqueous extracts of whole barley heated at 150, 190, and 230 °C were analyzed by GC-MS and their antioxidant properties were studied in vitro, in bulk oil, or in an oil-in-water (O/W) emulsion systems. More chemicals were detected in the ethanolic extract than in the aqueous extract from heated barley; heating decreased the contents of detected chemicals. Organic acids, mono- and di-saccharides, sugar alcohols, and glycerol were the major chemicals detected in both the extracts. Ethanolic extracts possessed higher in vitro antioxidant activities than the aqueous extracts. However, this trend was not clearly observed in the bulk oil and O/W emulsion. For O/W emulsions, ethanolic extracts obtained following heating at 150 °C prevented lipid oxidation better than others. Therefore, heat treatment at 150 °C is recommended to enhance the antioxidant activities of whole barley.

Metabolite analysis and anti-obesity effects of celery seed in 3T3-L1 adipocytes.

Celery seeds were fractioned successively by organic solvents, and fractions were screened for their antioxidant properties. Metabolites of high antioxidative fractions were analyzed, and then anti-obesity properties and mechanisms of selected fractions were evaluated in 3T3-L1 adipocytes. Celery seed ethanol extract (CSE) and celery seed ethyl acetate fraction (CSEA) possessed higher in vitro antioxidant properties, including radical scavenging and total phenolic content, than that of hexane, butanol, and water fractions. Total of 43 and 19 metabolites were identified from CSE and CSEA, respectively, by gas chromatography-mass selective detector. Isoferulic acid and p-coumaric acid were only found in CSEA. CSEA possessed higher anti-adipogenesis in the 3T3-L1 cells than CSE by decreasing adipogenic hormones, including leptin and adiponectin. Expression levels of adipocyte-related transcription factors and genes such as C/EBPα, PPARγ, aP2, and FAS decreased to comparable levels of control. CSEA could be used as a natural ingredient with antioxidant and anti-obesity functionality.

Volatile Profiles of Five Variants of Abeliophyllum distichum Flowers Using Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) Analysis.

Abeliophyllum distichum (Oleaceae), which is the only species in the monotypic genus and is grown only on the Korean peninsula, has a high scarcity value. Its five variants (white, pink, round, blue, and ivory) have different morphological characteristics in terms of the color of petals and sepals or shape of the fruits. Despite its high value, there has been no study on variant classification except in terms of their morphological characteristics. Thus, we performed a volatile component analysis of A. distichum flowers and multivariate data analyses to reveal the relationship between fragments emitted from five variants of A. distichum flowers with their morphological characteristics. As a result, 66 volatile components of this plant were identified by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS), showing unique patterns for each set of morphological characteristics, especially the color of the petals. These results suggest that morphological characteristics of each variant are related to the volatile composition.

Methanol extract of Sedum oryzifolium and its constituent, trehalose, impede the invasiveness of oral squamous cell carcinoma cell lines via downregulation of Slug.

BACKGROUND: Sedum species are reported to possess diverse pharmacological activities in various solid tumors. However, the anticancer functions of Sedum orizyfolium and its constituents have never been determined in human cancers. PURPOSE: The present study focused on addressing the inhibition efficacy of the methanol extract of S. orizyfolium (MESO) and its constituents and the molecular mechanism underlying invasion and epithelial-to-mesenchymal transition (EMT) in oral squamous cell carcinoma (OSCC) cell lines. STUDY DESIGN/METHODS: After MESO treatment, a wound-healing assay, an invasion assay, and immunocytochemistry were performed in OSCC cell lines, coupled with in silico analysis and immunohistochemistry in OSCC patient samples, to investigate the role of the EMT transcription factor Slug. Trehalose, an active component of MESO, was identified through gas chromatography-mass spectrometry. RESULTS: Among the methanol extracts of 18 various wild plants from South Korea, MESO exhibited the highest anticancer functionality in OSCC cells by downregulating Slug expression. In silico analysis and immunohistochemistry indicated that elevated Slug levels are remarkably associated with tumor progression and invasion in patients with OSCC, suggesting that changes in Slug expression alter EMT progression and invasion in OSCC. Notably, treatment with trehalose, a sugar component of MESO, inhibited invasiveness and Slug expression in OSCC cells. CONCLUSION: Cumulatively, this study highlighted the beneficial role of MESO and trehalose in the inhibition of invasiveness of OSCC cells via suppression of Slug expression and suggested a new design for potential chemotherapeutic drugs against OSCC.

A dietary anthocyanin cyanidin-3-O-glucoside binds to PPARs to regulate glucose metabolism and insulin sensitivity in mice.

We demonstrate the mechanism by which C3G, a major dietary anthocyanin, regulates energy metabolism and insulin sensitivity. Oral administration of C3G reduced hepatic and plasma triglyceride levels, adiposity, and improved glucose tolerance in mice fed high-fat diet. Hepatic metabolomic analysis revealed that C3G shifted metabolite profiles towards fatty acid oxidation and ketogenesis. C3G increased glucose uptake in HepG2 cells and C2C12 myotubes and induced the rate of hepatic fatty acid oxidation. C3G directly interacted with and activated PPARs, with the highest affinity for PPARα. The ability of C3G to reduce plasma and hepatic triglycerides, glucose tolerance, and adiposity and to induce oxygen consumption and energy expenditure was abrogated in PPARα-deficient mice, suggesting that PPARα is the major target for C3G. These findings demonstrate that the dietary anthocyanin C3G activates PPARs, a master regulators of energy metabolism. C3G is an agonistic ligand of PPARs and stimulates fuel preference to fat.

1H-nuclear magnetic resonance spectroscopy-based metabolic assessment in a rat model of obesity induced by a high-fat diet.

Obesity, whose prevalence is increasing rapidly worldwide, is recognized as a risk factor for diabetes, cardiovascular disease, liver disease, and renal disease. To investigate metabolic changes in the urine of a rat model of obesity induced by a high-fat diet (HFD), rats were divided into the following four groups based on the diet type and degree of weight gain: normal-diet (ND) low gainers, ND high gainers, HFD low gainers, and HFD high gainers. Biochemical analyses of visceral fat-pad weight, plasma, and liver tissues were performed. The (1)H-nuclear magnetic resonance ((1)H-NMR) spectra of urine were analyzed using multivariate statistical analysis to identify the separation of the groups. It was observed that the metabolic profile of urine obtained by (1)H-NMR-spectroscopy-based metabolomic analysis differed between ND low gainers and ND high gainers even though these animals consumed the same normal diet. Several key metabolites in urine, such as betaine, taurine, acetone/acetoacetate, phenylacetylglycine, pyruvate, lactate, and citrate contributed to the classification of these two groups. The metabolic profile of urine also differed between ND low gainers and HFD high gainers, which consumed the different diet and showed a different weight gain. This study has identified features of urine metabolites in various groups and demonstrated the reliability of an NMR-based metabolomics approach to investigate the effects of the diet and the physical constitution on obesity.

Classification of fermented soymilk during fermentation by 1H NMR coupled with principal component analysis and elucidation of free-radical scavenging activities.

Changes in metabolites in fermented soymilk prepared with selected Bifidobacterium and Streptococci strains were analyzed using a (1)H-NMR-based metabolomic technique. Principal components analysis (PCA) allowed the clear separation of 50% methanol extracts from fermented soymilk with different fermentation times by combining principal components PC1 and PC3, which accounted for 55.1% of the total variance. Loading plot analysis was performed to select major compounds contributing to the separation, and the relative levels of selected metabolites were determined. In addition, the free-radical scavenging activities of each sample were investigated, and the underlying mechanisms were elucidated by determining the total phenolics and total flavonoids contents of each sample. The present study suggests the usefulness of combining (1)H-NMR with PCA in discriminating fermented soymilk samples with different fermentation times, and elucidates of the factors affecting free-radical scavenging activities of fermented soymilk.

Metabolic discrimination of Catharanthus roseus calli according to their relative locations using (1)H-NMR and principal component analysis.

Creating a plant-cell suspension culture involves first transferring the callus into liquid media, but there are no objective criteria for selecting the location of the callus to be transferred. In this study, inner and outer cells of Catharanthus roseus with various elicitors in solid-state cultures were differentiated by (1)H NMR (nuclear magnetic resonance) spectrometry and principal component analysis (PCA). It was found that the samples of various elicitors and relative locations could be separated in PCA-derived score plots. Especially, there was a clear separation between nontreated samples and those cotreated with silver nitrate and methyl jasmonate. Loading-plot analysis was therefore applied to data obtained from nontreated samples and those cotreated with silver nitrate and methyl jasmonate to determine the separation of major metabolites on score plots. The levels of valine, lactic acid, threonine, alanine, arginine, acetic acid, malic acid, succinic acid, citric acid, asparagine, choline, lactose, fumaric acid, phenylalanine, tryptophan, and formic acid were higher in the inner callus than in the outer callus, whereas 2-oxoglutaric acid, oxalacetic acid, sucrose, and glucose dominated in the outer callus. The results obtained in this study suggest that inner and outer calli can be differentiated by (1)H-NMR-based metabolomic analysis.

Classification of fermented soybean paste during fermentation by 1H nuclear magnetic resonance spectroscopy and principal component analysis.

Fermented soybean paste (doenjang, FSP) is a traditionally fermented Korean food produced by fermentation with various microorganisms that is known to exhibit various beneficial bioactivities. To investigate the changes in nonvolatile metabolites of FSP during fermentation, samples produced with six fermentation times were analyzed using an (1)H nuclear magnetic resonance spectroscopy (NMR)-based metabolomics technique. This revealed clear separation of 50% methanol extracts of the FSP samples with different fermentation times in the principal component plots by combining PC1 and PC2, which cumulatively accounted for 94.2% of the variance. Major compounds contributing to the separation of 50% methanol extracts of FSP with various fermentation times were isoleucine/leucine, lactate, alanine, acetic acid, glutamine, choline, tyrosine, and phenylalanine. In addition, the (1)H NMR spectra of chloroform extracts were separated mainly by a combination of PC1 and PC3, which accounted for 72.6% of the variance. The present study suggests the usefulness of a (1)H NMR-based metabolomics approach to discriminate FSP samples subjected to different fermentation times, and this is the first report regarding metabolomic profiling of FSP.

Classification and prediction of free-radical scavenging activities of dangyuja (Citrus grandis Osbeck) fruit extracts using (1)H NMR spectroscopy and multivariate statistical analysis.

Different parts of dangyuja (Citrus grandis Osbeck) fruits at different maturation stages were classified using a (1)H NMR-based metabolomic technique. Principal components analysis allowed the clear separation of fractions extracted with 50% methanol of different parts of dangyuja fruits at different maturation stages by combining principal components PC1 and PC2, which together accounted for 80.4% of the variance. A loading-plot analysis revealed that sucrose, glucose, oxaloacetic acid and citric acid were dominant in mature flesh, while naringin, tyramine, proline and alanine were dominant in immature fruit samples. Projections to latent structures using a partial least squares (PLS) model were used to predict the free-radical scavenging activities (FRSA) of dangyuja fruit extracts based on their (1)H NMR spectra. The present study suggests the usefulness of combining (1)H NMR spectroscopy with multivariate statistical analysis for discriminating dangyuja fruit samples, and predicting the FRSA of different parts of dangyuja fruit samples at different stages of maturation.