Gromwell (Lithospermum erythrorhizon) Attenuates High-Fat-Induced Skeletal Muscle Wasting by Increasing Protein Synthesis and Mitochondrial Biogenesis.

Gromwell (Lithospermum erythrorhizon, LE) can mitigate obesity-induced skeletal muscle atrophy in C2C12 myotubes and high-fat diet (HFD)-induced obese mice. The purpose of this study was to investigate the anti-skeletal muscle atrophy effects of LE and the underlying molecular mechanism. C2C12 myotubes were pretreated with LE or shikonin, and active component of LE, for 24 h and then treated with 500 µM palmitic acid (PA) for an additional 24 h. Additionally, mice were fed a HFD for 8 weeks to induced obesity, and then fed either the same diet or a version containing 0.25% LE for 10 weeks. LE attenuated PA-induced myotubes atrophy in differentiated C2C12 myotubes. The supplementation of LE to obese mice significantly increased skeletal muscle weight, lean body mass, muscle strength, and exercise performance compared with those in the HFD group. LE supplementation not only suppressed obesity-induced skeletal muscle lipid accumulation, but also downregulated TNF-α and atrophic genes. LE increased protein synthesis in the skeletal muscle via the mTOR pathway. We observed LE induced increase of mitochondrial biogenesis and upregulation of oxidative phosphorylation related genes in the skeletal muscles. Furthermore, LE increased the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha and the phosphorylation of adenosine monophosphate-activated protein kinase. Collectively, LE may be useful in ameliorating the detrimental effects of obesity-induced skeletal muscle atrophy through the increase of protein synthesis and mitochondrial biogenesis of skeletal muscle.

Geniposide attenuates muscle atrophy via the inhibition of FoxO1 in senescence-accelerated mouse prone-8.

BACKGROUND: Geniposide (GP) is an iridoid glycoside that is present in nearly 40 species, including Gardenia jasminoides Ellis. GP has been reported to exhibit neuroprotective effects in various Alzheimer's disease (AD) models; however, the effects of GP on AD models of Caenorhabditis elegans (C. elegans) and aging-accelerated mouse predisposition-8 (SAMP8) mice have not yet been evaluated. PURPOSE: To determine whether GP improves the pathology of AD and sarcopenia. METHODS: AD models of C. elegans and SAMP8 mice were employed and subjected to behavioral analyses. Further, RT-PCR, histological analysis, and western blot analyses were performed to assess the expression of genes and proteins related to AD and muscle atrophy. RESULTS: GP treatment in the AD model of C. elegans significantly restored the observed deterioration in lifespan and motility. In SAMP8 mice, GP did not improve cognitive function deterioration by accelerated aging but ameliorated physical function deterioration. Furthermore, in differentiated C2C12 cells, GP ameliorated muscle atrophy induced by dexamethasone treatment and inhibited FoxO1 activity by activating AKT. CONCLUSION: Although GP did not improve the AD pathology in SAMP8 mice, we suggest that GP has the potential to improve muscle deterioration caused by aging. This effect of GP may be attributed to the suppression of FoxO1 activity.

Downregulation of ADAMTS3 Suppresses Stemness and Tumorigenicity in Glioma Stem Cell.

AIMS: Glioblastoma multiforme (GBM) is the most aggressive type of human brain tumor, with a poor prognosis and a median overall survival of fewer than 15 months. Glioma stem cells (GSCs) have recently been identified as a key player in tumor initiation and therapeutic resistance in GBM. ADAMTS family of metalloproteinases is known to cleave a wide range of extracellular matrix substrates and has been linked to tissue remodeling events in tumor development. Here, we investigate that ADAMTS3 regulates GSC proliferation and self-renewal activities, and tumorigenesis in orthotopic xenograft models. METHODS: ADAMTS3 mRNA expression levels in normal human astrocyte (NHA), glioma, and GSCs cell lines were compared. After knockdown of ADAMTS3, alamarBlue assay, in vitro limiting dilution, and orthotopic xenograft assays were performed. To investigate the tumor-associated roles of ADAMTS3, several statistical assays were conducted using publicly available datasets. RESULTS: ADAMTS3 level was remarkably higher in GSCs than in NHA, glioma cell lines, and their matched differentiated tumor cells. Interestingly, knockdown of ADAMTS3 disrupted GSC's proliferation, self-renewal activity, and tumor formation in vivo. Furthermore, ADAMTS3 could be used as an independent predictor of malignancy progression in GBM. CONCLUSION: We identified ADAMTS3 as a potential therapeutic target for GBM.

Bamboo Salt and Triple Therapy Synergistically Inhibit Helicobacter pylori-Induced Gastritis In Vivo: A Preliminary Study.

Helicobacter pylori infections are a major cause of gastrointestinal disorders, including gastric ulcers, gastritis, and gastric cancer. Triple therapy, using two antibiotics and a proton pump inhibitor, is recommended for the treatment of H. pylori infections. However, antibiotic resistance in H. pylori is an emerging issue. Bamboo salt, a traditional Korean salt made by baking solar sea salt in bamboo barrels, can ameliorate the symptoms of various gastrointestinal diseases. Herein, we compared the anti-H. pylori activity of triple therapy (clarithromycin, metronidazole, and omeprazole), solar salt, and bamboo salt in vivo as a preliminary study. Four-week-old C57BL/6 male mice were inoculated for eight weeks with the H. pylori Sydney Strain 1 (SS-1) and orally administered triple therapy drugs and salts for five days. The transcript levels of the H. pylori-expressed gene CagA and inflammatory cytokines Tnfα and Il-1ß significantly decreased in the bamboo salt treated mice than those in the H. pylori-infected control group. This effect was further enhanced by using triple therapy and bamboo salt together. Solar salt caused modest inhibition of H. pylori-induced inflammation. We also demonstrated the synergistic effects of bamboo salt and triple therapy against H. pylori. Thus, bamboo salt may be a potential candidate agent against the treatment of H. pylori-associated gastritis.

Inhibitory Effects of Acetyloctadecadienediynoic Acid Isolated from Leaves of Dendropanax morbiferus on Viability and Self-Renewal Activity of Glioma Stem-Like Cells.

Glioblastoma (GBM) is one of the most dangerous brain tumors in humans. The median survival of patients with GBM is <18 months. Glioma stem-like cells (GSCs), a small subpopulation of cells with stem cell-like characteristics found within GBM, are regarded as the main cause of GBM malignancy. Therefore, targeting GSCs presents an important therapeutic strategy for reducing the aggressiveness of tumors. In this study, we examined effects of (9Z,16S)-16-O-acetyl-9,17-octadecadiene-12,14-diynoic acid (AODA), a diacetylenic carboxylic acid isolated from leaves of Dendropanax morbiferus, on viability and self-renewal activity of GSCs. AODA substantially decreased GSC growth, causing apoptotic cell death as assessed by Annexin V/PI staining and morphological alterations by optical diffraction tomography. Interestingly, treatment with AODA suppressed ''stem-like features'' in vitro by limiting dilution assays and real-time polymerase chain reaction analysis. In addition, Western blotting revealed that AODA treatment decreased expression levels of phosphorylated AKT and phosphorylated ERK in GSC11 cells. Taken together, our results indicate that AODA could be considered a new therapeutic candidate to target GSCs.

Sprouty 1 is associated with stemness and cancer progression in glioblastoma.

Glioblastoma multiforme (GBM) is the most severe type of human brain tumor, with a poor prognosis and a low survival rate. GBM is composed of a variety of cell types, including glioma stem-like cells (GSCs), which attribute to its therapeutic resistance (Boyd et al., 2020). Sprouty1 (SPRY1) was first identified as a receptor tyrosine kinases (RTK) signaling mediator in a mammalian cell (Christofori, 2003), however, its role in GBM is unknown. Therefore, the goal of this study was to investigate the role of SPRY1 in the stemness and aggressiveness of GSCs. The mRNA expression levels of SPRY1 were confirmed using quantitative reverse transcription PCR (RT-qPCR) in normal human astrocytes (NHA), glioma cells, and glioma stem cells. SPRY1 expression was inhibited in glioma stem cells using small interference RNA (siRNAs) to examine its role in cell proliferation and tumorsphere formation. Bioinformatics analyses were also employed to investigate the association of SPRY1 expression with patient survival, tumor grade, and subtypes publicly available datasets. We demonstrated that SPRY1 is highly expressed in glioma stem cells than in NHA, glioma cells, and differentiated glioma stem cells. siRNA-mediated downregulation of SPRY1 expression decreased the stemness and self-renewal ability in GSC11. Bioinformatics results showed that high SPRY1 expression correlates with poor overall survival in glioma patients. Our findings suggest that SPRY1 contributes to the stemness and aggressiveness of GBM.

Chrysanthemum zawadskil Herbich attenuates dexamethasone-induced muscle atrophy through the regulation of proteostasis and mitochondrial function.

Chrysanthemum zawadskii Herbich (CZH) is used in traditional medicine to treat inflammatory diseases and diabetes. However, the effects of CZH on muscle wasting remains to be studied. Here, we investigated the effect of CZH on dexamethasone (DEX), a synthetic glucocorticoid, induced muscle atrophy. To examine the effect of CZH on muscle atrophy, C2C12 myotubes were co-treated with DEX and CZH for 24 h. The treatment with CZH prevented DEX-induced myotube atrophy in a dose-dependent manner. CZH inhibited the DEX-induced decrease of the MHC isoforms and the upregulation of atrogin-1 and MuRF1 in C2C12 differentiated cells. C57BL/6 mice were supplemented with 0.1 % CZH for 8 weeks, with DEX-induced muscle atrophy stimulated in the last 3 weeks. In the mice, CZH supplementation effectively reversed DEX-induced skeletal muscle atrophy and increased the exercise capacity of the mice through the inhibition of glucocorticoid receptor translocation. Additionally, we observed that DEX-evoked impaired proteostasis was ameliorated via the Akt/mTOR pathway. CZH also prevented the DEX-induced decrease in the mitochondrial respiration. HPLC analysis demonstrated the highest concentration of acacetin-7-O-ß-d-rutinoside (AR) among 4 compounds. Moreover, AR, a functional compound of CZH, prevented DEX-evoked muscle atrophy. Thus, we suggest that CZH could be a potential therapeutic candidate against muscle atrophy and AR is the main functional compound of CZH.

High expression of RFX4 is associated with tumor progression and poor prognosis in patients with glioblastoma.

Aim: Glioma stem cells (GSCs) have been shown to contribute to tumor development and recurrence, therapeutic resistance, and cellular heterogeneity of glioblastoma multiforme (GBM). Recently, it has been reported that GSCs lose their self-renewal ability and tumorigenic potential upon differentiation. In this study, we identified Regulatory Factor X4 (RFX4) gene to regulate GSCs' survival and self-renewal activity in the GBM patients samples.Materials and methods: We utilized public datasets from the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Ivy Glioblastoma Atlas Project, and The Human Protein Atlas to screen candidate genes which are associated with the development of GBM and poor patients survival. Small hairpin RNA (shRNA) lentivirus was applied to knockdown RFX4 gene in GSCs.Results: We found that RFX4 mRNA expression among the RFX family was particularly reduced during GSC differentiation. RT-qPCR analysis revealed significant downregulation of RFX4 and stem cell markers (CD15 and CD133) mRNA expressions in primary human GBM-derived GSCs cultured under serum condition. Consistently, GSCs showed significantly elevated RFX4 mRNA expression levels compared to normal astrocytes, NHA, whereas glioma cells did not. Furthermore, analysis of the TCGA data set revealed that RFX4 is highly expressed in GBM, and contributes to the lowering of patient survival. Depletion of RFX4 using shRNA lentivirus in patient GBM-derived GSCs decreased neurosphere formation and cell viability.Conclusion: These results suggest that RFX4 is a potential risk factor for maintaining the stemness of GSCs and making glioma more malignant, and thus, could be a promising target of GBM treatment.

3-Pentylcatechol, a Non-Allergenic Urushiol Derivative, Displays Anti-Helicobacter pylori Activity In Vivo.

We previously reported that 3-pentylcatechol (PC), a synthetic non-allergenic urushiol derivative, inhibited the growth of Helicobacter pylori in an in vitro assay using nutrient agar and broth. In this study, we aimed to investigate the in vivo antimicrobial activity of PC against H. pylori growing in the stomach mucous membrane. Four-week-old male C57BL/6 mice (n = 4) were orally inoculated with H. pylori Sydney Strain-1 (SS-1) for 8 weeks. Thereafter, the mice received PC (1, 5, and 15 mg/kg) and triple therapy (omeprazole, 0.7 mg/kg; metronidazole, 16.7 mg/kg; clarithromycin, 16.7 mg/kg, reference groups) once daily for 10 days. Infiltration of inflammatory cells in gastric tissue was greater in the H. pylori-infected group compared with the control group and lower in both the triple therapy- and PC-treated groups. In addition, upregulation of cytokine mRNA was reversed after infection, upon administration of triple therapy and PC. Interestingly, PC was more effective than triple therapy at all doses, even at 1/15th the dose of triple therapy. In addition, PC demonstrated synergism with triple therapy, even at low concentrations. The results suggest that PC may be more effective against H. pylori than established antibiotics.

B3GNT5 is a novel marker correlated with stem-like phenotype and poor clinical outcome in human gliomas.

AIMS: Glioblastoma multiforme (GBM) is the most lethal tumor with a median patient survival of 14 to 15 months. Glioma stem cells (GSCs) play a critical role in tumor initiation and therapeutic resistance in GBM. B3GNT5 has been suggested as the key glycosyltransferase in the biosynthesis of the (neo-) lacto series of glycosphingolipid. In this study, we evaluated the B3GNT5 expression in GSCs as well as the correlation with clinical data in GBM. METHODS: The mRNA levels of B3GNT5 in normal astrocytes, four glioma cell lines, and four GSCs were evaluated using real-time PCR. Small interference RNAs (siRNAs) were used to inhibit B3GNT5 expression and analyze its ability to form neurospheres. Statistical analyses were conducted to determine the association with B3GNT5 expression and tumor grade and GBM subtypes as well as patient survival using public datasets. RESULTS: B3GNT5 expression was significantly elevated in GSCs compared with normal astrocytes, glioma cell lines, and their matched differentiated tumor cells. Knockdown of B3GNT5 in GSCs decreased the neurosphere formation. Patients with high B3GNT5 expression had a short overall survival. B3GNT5 is correlated with classical and mesenchymal GBM subtypes. CONCLUSION: The findings suggest the central role of B3GNT5 in regulating malignancy of GBM.

Does 3-pentadecylcatechol, an urushiol derivative, get absorbed in the body? A rat oral administration experiment.

Urushiols are important active compounds found in the sap of the lacquer tree (Rhus verniciflua Stokes). Recently, various biological effects of urushiols, such as antioxidant, antimicrobial, and anticancer activities, have been reported. However, urushiols can also induce skin allergies. Nevertheless, the lacquer tree has traditionally been used in Korea as a folk medicine. In this study, we evaluated the absorption and metabolism of 3-pentadecylcatechol (PDC), a natural urushiol. PDC (48.0 mg/kg body wt.) in 1 mL propylene glycol was orally administered to rats (Sprague-Dawley, male, 6 weeks old). Blood plasma, urine, and feces were collected, separately. PDC was not detected in the extracts from rat blood plasma and urine. However, 89.4 ± 5.2% of the orally administered PDC was detected in the feces extracts, indicating that PDC was predominantly excreted and not absorbed.

Ionization Neutralizes the Allergy-Inducing Property of 3-Pentadecylcatechol: A Urushiol Derivative.

Urushiols are amphipathic compounds found in Rhus verniciflua Stokes that exhibit various biological activities. However, their practical use is very restricted due to their contact dermatitis-inducing property. Therefore, we applied the ionization method to remove the allergenic properties of the urushiols and to increase their usability. One of the natural urushiols, 3-pentadecylcatechol (PDC), was heated for 30 min with a solution of H2O and sodium carbonate (Na2CO3). The reaction product was analyzed by electrospray ionization mass spectrometry (ESI-MS). Ionized PDC with an m/z value of 316.9 and complexed PDCs with Na+ of 1 - 3 atoms with m/z values of 340.8, 365.2, and 380.8 were detected. PDC and ionized PDC (3 µmol/3 mg of Vaseline) treatments were applied on the rear of left ear of Sprague-Dawley rats once daily for 10 days. Erythema and swelling were observed on the ear skin treated with PDC, but not in case of ionized PDC. Compared with control, contact hypersensitivity-related biomarkers (neutrophils, eosinophils, immunoglobulin E, and histamine) in the blood were significantly higher only in the PDC-treated group. In addition, Il-1b, Il-6, Tnfα, and Cox-2 mRNA expression levels were dramatically increased in the ear tissue of PDC-treated rats, but in the ionized PDC-treated group, they were similar to those in the control group. Overall, it was confirmed that the allergenic property of the urushiol PDC was removed by ionization. This method is expected to be useful for preventing allergy induction in cooking and food processing using R. verniciflua Stokes.

Protocatechuic Acid from Pear Inhibits Melanogenesis in Melanoma Cells.

Despite the critical role of melanin in the protection of skin against UV radiation, excess production of melanin can lead to hyperpigmentation and skin cancer. Pear fruits are often used in traditional medicine for the treatment of melasma; therefore, we investigated the effects of pear extract (PE) and its component, protocatechuic acid (PCA), on melanogenesis in mouse melanoma cells. We found that PE and PCA significantly suppressed melanin content and cellular tyrosinase activity through a decrease in the expression of melanogenic enzymes and microphthalmia-associated transcription factor (Mitf) in α-melanocyte stimulating hormone-stimulated mouse melanoma cells. Moreover, PCA decreased cyclic adenosine monophosphate (cAMP) levels and cAMP-responsive element-binding protein phosphorylation, which downregulated Mitf promoter activation and subsequently mediated the inhibition of melanogenesis. These results suggested that pear may be an effective skin lightening agent that targets either a tyrosinase activity or a melanogenic pathway.

Metabolism and antioxidant effect of malaxinic acid and its corresponding aglycone in rat blood plasma.

Malaxinic acid (MA) is a phenolic acid compound, found mainly in pear fruits (Pyrus pyrifolia N.), that is isoprenylated on the C-3 position of benzoic acid. Recently, the effects of prenylated phenolics on health have received much interest owing to their reported potent beneficial biological effects. We conducted a comparative study in rats to determine the metabolism, pharmacokinetics, and antioxidative activities of MA and its corresponding aglycone (MAA). MA and MAA were orally administered to rats (Sprague-Dawley, male, 6 weeks old) and their metabolites in plasma were analyzed. In addition, the MA metabolites in plasma were separated and the structures were confirmed via NMR and HR-MS analyses. The antioxidative activities of MA and MAA were evaluated by measuring their inhibitory effects on the 2,2'-azobis(2-amidinopropane)dihydrochloride- or copper ion-induced lipid peroxidation of rat plasma. MA was not absorbed in the intact form (the glucoside); both MA and MAA were absorbed as MAA and its metabolite form (glucuronide or sulfate). Moreover, the observed metabolite was the glucuronate of MAA rather than the glucuronide or sulfate. Concentrations of the free form of aglycone (MA administration, 4.6 ± 2.2µM; MAA administration, 7.2 ± 2.3µM) and total MAA (MA administration, 19.6 ± 4.4µM; MAA administration, 21.7 ± 3.3µM) in plasma reached a maximum at 15min after the oral administration of MA and MAA, respectively. The relative inhibitory effects on the formation of cholesteryl ester hydroperoxides in plasma collected at 15min after the oral administration of MA, MAA, and p-hydroxybenzoic acid (p-HBA) were as follows: MAA > MA ≥ p-HBA > control. Although the majority of MA and MAA is metabolized to conjugates, the compounds may contribute to the antioxidant defenses in the blood circulation owing to the presence of a phenolic hydroxyl group in the free form.

Isolation of five proanthocyanidins from pear (Pyrus pyrifolia Nakai) fruit peels.

Five proanthocyanidins, two B-type dimers and three A-type trimers, were purified and isolated from the fruit peels of Pyrus pyrifolia Nakai cv. Chuhwangbae. The isolated compounds were identified as (-)-epicatechin gallate-(4ߠ→ 8)-(-)-epicatechin (Hahashi et al. in Ann Biol Res 3:3200-3207, 2012), (-)-epicatechin-(4ߠ→ 8)-(-)-epicatechin (procyanidin B2) (Tanrioven and Eksi in Food Chem 93:89-93, 2005), (-)-epicatechin-(4ߠ→ 8, 2ߠ→ O-7)-(-)-epicatechin-(4ߠ→ 8)-(-)-epicatechin (cinnamtannins B1) (Salta et al. in J. Fun. Food 2: 153-157, 2010), (-)-epicatechin-(4ߠ→ 8)-(-)-epicatechin-(4ߠ→ 8, 2ߠ→ O-7)-(-)-epicatechin (aesculitannin A) (Challice and Westwood in Phytochemistry 11: 37-44, 1972), and (-)-epicatechin-(4ߠ→ 6)-(-)-epicatechin-(4ߠ→ 8, 2ߠ→ O→7)-(-)-epicatechin (Es-Safi et al. in J Agric Food Chem 54: 6969-6977, 2006). Their structures were determined by nuclear magnetic resonance and mass spectrometry. The three A-type proanthocyanidin trimers were identified for the first time from pear.

Phenolics and eudesmanolide from aged common sage exudate with sugar.

Nineteen compounds including one new flavanone were isolated from the juice of aged common sage exudate with sugar (ACSE). The isolated compounds were identified by NMR and MS analyses as levodopa methyl ester (1), 3,4-dihydroxybenzoic acid (2), (S)-8-hydroxy-4-hydroxy-phenylpropanoic acid (3), 4-hydroxybenzoic acid ethyl ester (4), cis-caffeic acid (5), trans-caffeic acid (6), esculetin (7), (S)-8-hydroxy-3,4-dihydroxy-phenylpropanoic acid ethyl ester (8), cis-rosmarinic acid (9), trans-rosmarinic acid (10), trans-rosmarinic acid methyl ester (11), 6-methoxy-7,8,3',5'-tetrahydroxyflavanone (12), nepetin (13), trans-caffeic acid ethyl ester (14), luteolin (15), cis-caffeic acid ethyl ester (16), 6-methoxynaringenin (17), 1α-acetoxy-2-oxo-eudesman-3,7(11)-dien-8ß,12-olide (18), and hispidulin (19). Compound 12 was isolated for the first time from nature and seven compounds (1, 3, 4, 7, 8, 14, and 18) were newly identified from common sage. Of them, 15 isolated phenolic compounds (1-3, 5-8, 10-15, 17, and 19) were detected in ACSE juice, while only 10 was detected in the fresh common sage.

A phenyl lipid alkaloid and flavone C-diglucosides from Spergularia marina.

A phenyl lipid alkaloid and seven phenolic compounds were isolated from the aerial part of Spergularia marina, a halophyte that grows on salt marshes and tidal flat. These compounds were identified as 2,4-di-tert-butylphenol, N-hexacosanoylanthranilic acid, tryptophan, 4-hydroxybenzyol glucopyranoside, luteolin 6-C-ß-D-glucopyranoside 8-C-ß-D-(2-O-feruloyl)glucopyranoside, luteolin 6-C-ß-D-(2-O-feruloyl)glucopyranoside 8-C-ß-D-glucopyranoside, apigenin 6-C-ß-D-glucopyranoside 8-C-ß-D-(2-O-feruloyl)glucopyranoside, and apigenin 6-C-ß-D-(2-O-feruloyl)glucopyranoside 8-C-ß-D-glucopyranoside. The structures were determined by nuclear magnetic resonance and electrospray ionization-mass spectroscopy.

Enhancement of antioxidative and antimicrobial activities of immature pear (Pyrus pyrifolia cv. Niitaka) fruits by fermentation with Leuconostoc mesenteroides.

Immature pear (Pyrus pyrifolia cv. Niitaka) fruits were fermented with Leuconostoc mesenteroides and Aspergillus oryzae, which are commonly used as starters for manufacturing fermented foods. Fermented immature pear fruit extracts (FIPF) by L. mesenteroides showed significantly higher radical-scavenging activity using DPPH, ABTS, superoxide anion, and hydroxyl radicals and reducing power capacity than unfermented immature pear fruit extracts. L. mesenteroides-FIPF more effectively inhibited the formation of cholesteryl ester hydroperoxide in copper ion-induced rat blood plasma. In addition, the L. mesenteroides-FIPF strongly inhibited tyrosinase activity and the growth of pathogenic skin bacteria. In contrast, enhanced antioxidative and antibacterial activities were not apparent in A. oryzae-FIPF. The antioxidative and antimicrobial activities of the fermented and unfermented immature pear fruits were correlated with the flavonoid contents. These results indicate that fermentation enhances antioxidative and antimicrobial activities of immature pear fruits.

New quinolinone alkaloids from chestnut (Castanea crenata Sieb) honey.

Two new quinolinone alkaloids and 13 known compounds were isolated from chestnut (Castanea crenata Sieb) honey. Two new compounds were determined to be 3-dihydro-spiro[2(1H),3'(1'H)-diquinoline]-3',4,4'-trione (spirodiquinolinone) and 3-(2'-piperidine)-kynurenic acid. In addition, 2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-one was identified for the first time from nature. In addition, 2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-one was newly identified from chestnut honey, although this compound has been synthesized before. The structures were determined by the NMR and electrospray ionization-mass spectroscopy (ESI-MS). Three compounds were qualified and quantitated in chestnut honey by selective multiple reaction monitoring (MRM) detection of LC-ESI-MS using the isolated compounds as external standards.

Change in chemical constituents and free radical-scavenging activity during Pear (Pyrus pyrifolia) cultivar fruit development.

Changes in chemical constituent contents and DPPH radical-scavenging activity in fruits of pear (Pyrus pyrifolia) cultivars during the development were investigated. The fruits of seven cultivars (cv. Niitaka, Chuhwangbae, Wonhwang, Hwangkeumbae, Hwasan, Manpungbae, and Imamuraaki) were collected at 15-day intervals after day 20 of florescence. Vitamins (ascorbic acid and α-tocopherol), arbutin, chlorogenic acid, malaxinic acid, total caffeic acid, total flavonoids, and total phenolics were the highest in immature pear fruit on day 20 after florescence among samples at different growth stages. All of these compounds decreased gradually in the fruit during the development. Immature pear fruit on day 35 or 50 after florescence exhibited higher free radical-scavenging activity than that at other times, although activities were slightly different among cultivars. The chemical constituent contents and free radical-scavenging activity were largely different among immature fruits of the pear cultivars, but small differences were observed when they matured.