Physicochemical properties and freeze-thaw stability of rice flour blends among rice cultivars with different amylose contents

The effectiveness of the rice flour blends (RFB) for improving the processing suitability of Dodamssal rice flour (DD), a functional rice variety with a relatively high amylose and resistance starch content, was investigated. Physicochemical properties and freeze-thaw stability of RFB composed of DD and four rice flour (RF) samples with different amylose contents were measured at different DD ratios. DD, which has low swelling power and low pasting viscosity properties, has improved some quality in terms of physicochemical properties by blending with other RF. Especially, non-additive behavior was observed in the blend with Geonyang No.2 RF (GY), a medium waxy variety, due to water competition caused by the difference in pasting temperature. The syneresis of DD was reduced by blending with 75% Hanareum No. 4 RF, with a gradual reduction effect observed following a repeated freeze-thaw cycle. GY significantly improved the low freeze-thaw stability of DD with only a 25% blend.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00989-7.

Bleeding risk in patients with atrial fibrillation treated with combined anti-platelet and NOAC therapy

Background

The combined use of antiplatelet agents (APT) and non-vitamin K antagonist oral anticoagulants (NOACs) in patient with atrial fibrillation (AF) is commonly encountered in clinical practice. The purpose of this study was to compare the clinical outcomes between combination therapy (NOAC and APT) and monotherapy (NOAC only).

Methods and results

We analyzed patients who were prescribed NOACs between January 2012 and December 2016. The primary outcome was major or any bleeding events and the secondary outcomes were stroke/systemic embolism (SE) and major adverse cardiac events (MACE). Of 1,068 participants, there were 264 (24.7%) patients in the combination group.

The prevalence of diabetes (p=0.017) and history of stroke and transient ischemic attacks (p<0.001) was higher in the combination group than in the monotherapy group. During the mean 14.6±9.8 months of follow-up, the incidence of any bleeding was significantly higher in the combination group than in the monotherapy group (p<0.001). Major bleeding, stroke/SE, and MACE between the two groups were similar. The rate of under-dosage NOACs prescriptions was higher in the combination group than in the monotherapy group (p=0.024).

Conclusions

The combination therapy had higher incidences of any bleeding events compared to the monotherapy. However, there was no difference in stroke/SE and MACE.

The bleeding risk in patients taking the combination of NOACs and APT should be carefully evaluated.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Primary and secondary outcomes

The volume of left atrium measured by multi-detector computed tomography can predict of long term outcome in catheter ablation of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

This study aimed to identify the volume left atrium (LA) and left atrial appendage (LAA) calculated by multidetector computed tomography (MDCT) is related to the long term out come of radiofrequency catheter ablation (RFCA) for atrial fibrillation(AF).

Methods

We analyzed data from 99 consecutive patients who referred for RFCA due to drug-refractory symptomatic AF (age 56 ± 10 years; 74% men; 64% paroxysmal AF). Prior to the procedure, all patients underwent ECG-gated 128 channels MDCT scan for assessment for pulmonary vein  anatomy, LA and LAA volume estimation, and electro-anatomical mapping integration. 

Results

The volume of LA and LAA calculated by CT was 142.6 ± 32.2 mL and 14.7 ± 6.0 mL, respectively. LA volume was smaller in paroxysmal AF(PAF) than persistent AF(PeAF) (133.9 ± 29.3 mL vs. 158.0 ± 31.4 mL, p < 0.0001) but  LAA volume was not significantly different between PAF and PeAF(13.9 ± 5.0 mL vs. 16.3 ± 7.3 mL, p = 0.09). Patients were classified into 2 groups by the LA volume of 160mL; group 1  (LA volume < 160mL,n = 73) and group 2 (LA volume ≥160mL, n = 26). After a mean follow up 12.6 ± 5.3 months, 78.8% of the patients maintained sinus rhythm after the index ablation. AF free survival was significantly greater in group  1 than group 2 (84.9% vs. 61.5% p = 0.017). No relationship was found between LAA volume and the outcome of RFCA. Multivariate analysis showed that the LA volume >160mL was an independent predictor of arrhythmia-free after ablation (Hazard ration 2.55, 95% confidential interval 1.02-6.35, p = 0.045)

Conclusion

Higher LA volume is independent risk factor for AF recurrence after RFCA but not LAA volume. The LA volume quickly assessed by MDCT could be a good predictor of long term recurrence after AF ablation.

Retarding Oxidative and Enzymatic Degradation of Phenolic Compounds Using Large-Ring Cycloamylose

The phenolic compounds (PCs) abundant in fruits and vegetables are easily browned by oxygen and browning enzymes, with subsequent destruction of nutrients during food processing and storage. Therefore, natural anti-browning additives are required to control these reactions. The aim of the present study was to investigate the feasibility of cycloamylose (CA) complexation as a way to improve stability of PCs against oxidation and browning enzymes. The complex was prepared by reacting enzymatically produced CA with a degree of polymerization of 23-45 with PCs in aqueous solution. No significant differences were observed between the PCs and their CA complexes in 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging experiments. However, the reduction rate of their antioxidant activity was clearly reduced in the presence of CA for as long as 4 weeks. At the studied concentrations, the activity of polyphenol oxidase on all of the tested PC species was inhibited in the presence of CA, although this effect was less evident as the substrate concentration increased. The higher the CA concentration added to apple juice, the lower the variation in the total color difference (ΔE*) during storage, confirming that CA could be used as an effective natural anti-browning agent. Our study is the first to study the potential of CA as a natural material for browning control. The results obtained will provide useful information for active food applications requiring oxidative stability in fruit products.

Clean label starch: production, physicochemical characteristics, and industrial applications

Recently, health-conscious consumers have a tendency to avoid the use of modified starch in their food products because of reluctance regarding food additives or chemical processes. The present paper considers the characteristics and manufacturing methods of clean label starch, which is free from chemical modification. Clean label starch manufacturing is mainly dependent on starch blending, physical and enzymatic modification methods. Physical modifications include ultrasound, hydrothermal (e.g., heat-moisture treatment and annealing), pre-gelatinization (e.g., drum drying, roll drying, spray cooking, and extrusion cooking), high-pressure (high hydrostatic pressure), and pulsed electric field treatments. These physical processes allow variation of starch properties, such as morphological, thermal, rheological, and pasting properties. Enzyme treatment can change the properties of starch more dramatically. Actual use of clean label starch with such altered properties has occurred in industry and is described here. This review may provide useful information on the current status and future direction of clean label starch in the field of food science.

Improving the Stability and Curcumin Retention Rate of Curcumin-Loaded Filled Hydrogel Prepared Using 4αGTase-Treated Rice Starch

In this study, 4-α-glucanotransferase (4αGTase)-treated rice starch (GS) was added after 1-h (1 GS) and 96-h (96 GS) treatments to the aqueous phase of a curcumin-loaded emulsion to produce filled hydrogels (1 GS-FH and 96 GS-FH, respectively). The relative protective effects of the FH system, native rice starch-based filled hydrogel (RS-FH), and emulsion without starch (EM), on curcumin were evaluated based on ultraviolet (UV) stability and simulated gastrointestinal studies. The UV stability and curcumin retention after in vitro digestion of the filled hydrogels (FH) samples were greater than those of the EM samples. RS-FH showed a 2.28-fold improvement in UV stability over EM due to the higher viscosity of RS. 1 GS-FH and 96 GS-FH increased curcumin retention by 2.31- and 2.60-fold, respectively, and the microstructure of 96 GS-FH, determined using confocal laser microscopy, remained stable even after the stomach phase. These effects were attributed to the molecular structure of GS, with decreased amylopectin size and amylose content resulting from the enzyme treatment. The encapsulation of lipids within the GS hydrogel particles served to protect and deliver the curcumin component, suggesting that GS-FH can be applied to gel-type food products and improve the chemical stability of curcumin.

Multidrug-resistant tuberculosis in South Korea: a retrospective analysis of national registry data in 2011-2015

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) poses a threat to public health as a result of high treatment costs and unsatisfactory outcomes.OBJECTIVE: To elucidate trend, demographic and clinical characteristics and treatment outcomes of patients with MDR-TB between 2011 and 2015 in South Korea.METHOD: Data of patients with MDR-TB diagnosed between 1 January 2011 and 31 December 2015 were retrieved from the nationwide Internet-based TB notification system and analysed retrospectively.RESULTS: During the study period, 5192 MDR-TB patients were notified. We identified an increasing number of MDR-TB patients among foreign populations (from 1.3% to 7.7%), decreasing resistance rates to other anti-TB drugs (e.g., resistance to pyrazinamide, from 40.9% to 28.2%), a decreasing interval from treatment initiation to negative conversion of sputum culture (from 165.7 to 103.7 days) and shortening of treatment duration (719.7 to 613.2 days). However, treatment success rates did not change, and had an average of 65.7%.CONCLUSION: Despite decreasing resistance rates to other drugs and faster treatment responses, treatment outcomes did not improve during the study period. Strict management of MDR-TB patients on treatment should be adopted to improve treatment outcomes.

Impacts of pre-rigor salting with KCl on technological properties of ground chicken breast

The objective of this study was to determine the impact of pre-rigor salting using KCl on the technological properties of ground chicken breast. Chicken breast muscle (M. pectoralis major and minor) was hot-debonded and salted with 2% NaCl (w/w), 1% NaCl+1% KCl mixture, or 2% KCl, respectively, within 30 min after slaughter. Post-rigor salting treatment was prepared with 2% NaCl at 24 h postmortem. All pre-rigor salting treatments showed higher ultimate pH, protein solubility, and final yield than post-rigor salting treatment (P < 0.05). However, the positive effects of pre-rigor salting on chicken breast differed by salt type. Pre-rigor salting with KCl resulted in higher ultimate pH and R-values of chicken breast than pre-rigor salting with NaCl (P < 0.05). Despite the high ultimate pH, pre-rigor salting with KCl resulted in lower protein solubility, final yield, and hardness of chicken breast than pre-rigor salting with NaCl (P < 0.05). These results indicate that pre-rigor salting with KCl could contribute to the maintenance of relatively excellent technological properties of pre-rigor chicken breasts compared to post-rigor salted chicken breast. However, this current study also suggests that the impact of KCl on technological properties in pre-rigor chicken breast, such as water-holding capacity, protein solubility, and texture, could be less effective than pre-rigor salting with NaCl at an identical percentage concentration.

Complex formation of a 4-α-glucanotransferase using starch as a biocatalyst for starch modification

A 4-α-glucanotransferases from Thermus thermophilus (TTαGT) possesses an extra substrate binding site, leading to facile purification of the intact enzyme using amylose as an insoluble binding matrix. Due to the cost of amylose and low recovery yield, starch was replaced for amylose as an alternative capturer in this study. Using gelatinized corn starch at pH 9 with 36-h incubation in the presence of 1 M ammonium sulfate increased the TTαGT-starch complex formation yield from 2 to 56%. In preparative-scale production, TTαGT produced in Bacillus subtilis was recovered by 42.1% with the same specific activity as that of purified TTαGT. Structural and rheological analyses of the enzymatically modified starches revealed that the starch complex exhibited catalytic performance comparable to soluble TTαGT, suggesting that the starch complex can be used as a biocatalyst for modified starch production without elution of the enzyme from the complex.

A Study on CYP2C19 and CYP2D6 Polymorphic Effects on Pharmacokinetics and Pharmacodynamics of Amitriptyline in Healthy Koreans

We performed a double-blinded, genotype-based stratification study to explore the pharmacokinetics and pharmacodynamics of amitriptyline according to CYP2C19 and CYP2D6 genotype in Korean subjects. Twenty-four healthy adults were grouped by genotype of CYP2C19 and CYP2D6. After a single dose of 25 mg of amitriptyline, blood samples were collected and anticholinergic effects were measured. The extent of N-demethylation of amitriptyline significantly decreased in subjects carrying two nonfunctional alleles of CYP2C19. The extent of hydroxylation of amitriptyline or nortriptyline was significantly reduced in subjects carrying two CYP2D6 decreased functional alleles compared with those with no or one decreased functional allele. The overall metabolic pathway of amitriptyline was more likely to be dominated by CYP2C19 than CYP2D6. The gene variations of CYP2C19 and CYP2D6 did not change the pharmacodynamic effect. The findings of this study will provide useful information on individualized drug treatment with amitriptyline considering both CYP2D6 and CYP2C19 gene variations.

High-yield cycloamylose production from sweet potato starch using Pseudomonas isoamylase and Thermus aquaticus 4-α-glucanotransferase

An optimal reaction condition for producing cycloamylose (CA) from sweet potato starch was investigated using a combination of isoamylase (from Pseudomonas sp.) and 4-α-glucanotransferase (from Thermus aquaticus, TAαGT). Starch was debranched by isoamylase for 8 h and subsequently reacted with TAαGT for 12 h. The yield and purity of CA products were determined using HPSEC and MALDI-TOFMS, respectively. Consequently, the maximum yield was 48.56%, exhibiting the highest CA production efficiency ever reported from starch. The CA products showed a wide range of the degree of polymerization (DP) with the minimum DP of 5. CA was also produced by simultaneous treatment of isoamylase and TAαGT. The yield was 3.31%, and the final products were contaminated by multiple branched and linear molecules. This result suggests that a former reaction condition (the sequential addition of isoamylase and TAαGT) is preferable for producing CA from sweet potato starch.

Robust MR assessment of cerebral blood volume and mean vessel size using SPION-enhanced ultrashort echo acquisition

Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆R2(⁎) and ∆R2) are widely used to investigate in vivo vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆R2(⁎)/∆R2). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based ∆R2(⁎) is hampered by its high sensitivity to magnetic field perturbations arising from air-tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based ∆R2(⁎) measurement with ultra-short echo time (UTE)-based ∆R1 contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue ∆R1 ratio, while independent spin-echo acquisition enabled simultaneous ∆R2 measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors.

Control of β-carotene bioaccessibility using starch-based filled hydrogels

β-Carotene was incorporated into three types of delivery system: (i) "emulsions": protein-coated fat droplets dispersed in water; (ii) "hydrogels": rice starch gels; and (iii) "filled hydrogels": protein-coated fat droplets dispersed in rice starch gels. Fat droplets in filled hydrogels were stable in simulated mouth and stomach conditions, but aggregated under small intestinal conditions. Fat droplets in emulsions aggregated under oral, gastric, and intestinal conditions. β-Carotene bioaccessibility was higher when encapsulated in filled hydrogels than in emulsions or hydrogels, which was attributed to increased aggregation stability of the fat droplets leading to a larger exposed lipid surface area. β-Carotene bioaccessibility in starch hydrogels containing no fat was very low (≈1%) due to its crystalline nature and lack of mixed micelles to solubilise it. The information presented may be useful for the design of rice-starch based gel products fortified with lipophilic nutraceuticals.

Ultrafast 3D spin-echo acquisition improves Gadolinium-enhanced MRI signal contrast enhancement

Long scan times of 3D volumetric MR acquisitions usually necessitate ultrafast in vivo gradient-echo acquisitions, which are intrinsically susceptible to magnetic field inhomogeneities. This is especially problematic for contrast-enhanced (CE)-MRI applications, where non-negligible T₂* effect of contrast agent deteriorates the positive signal contrast and limits the available range of MR acquisition parameters and injection doses. To overcome these shortcomings without degrading temporal resolution, ultrafast spin-echo acquisitions were implemented. Specifically, a multiplicative acceleration factor from multiple spin echoes (×32) and compressed sensing (CS) sampling (×8) allowed highly-accelerated 3D Multiple-Modulation-Multiple-Echo (MMME) acquisition. At the same time, the CE-MRI of kidney with Gd-DOTA showed significantly improved signal enhancement for CS-MMME acquisitions (×7) over that of corresponding FLASH acquisitions (×2). Increased positive contrast enhancement and highly accelerated acquisition of extended volume with reduced RF irradiations will be beneficial for oncological and nephrological applications, in which the accurate in vivo 3D quantification of contrast agent concentration is necessary with high temporal resolution.

The comparison of femoral and radial arterial blood pressures during pediatric liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) is frequently associated with dramatic hemodynamic changes; thus, it is critical to accurately monitor blood pressure. Although comparisons between femoral arterial blood pressure (FABP) and radial arterial blood pressure (RABP) have been reported in adult liver recipients, we compared FABP with RABP in pediatric recipients.

METHODS

Thirty-five pediatric liver recipients younger than 13 years of age were included in this prospective, observational study. We measured simultaneous FABP and RABP in the femoral and radial arteries at nine time points during the procedure, including: baseline (after anesthetic induction); 1 hour thereafter; 30 minutes after the beginning of the anhepatic period as well as 0, 1, 3, 5, 15, and 60 minutes after graft reperfusion.

RESULTS

Of the 35 pediatric liver recipients, 2 infants and 1 13-month-old child were excluded from the analysis because of radial arterial catheter malfunction. The remaining 32 patients including 16 infants and 16 children all showed significantly higher systolic and mean FABP than RABP during most stages of pediatric OLT. Overall diastolic FABP measurements were similar to diastolic RABP throughout the study.

CONCLUSIONS

Systolic and mean FABP were significantly higher than RABP during most stages of pediatric OLT. Radial arterial catheter malfunctions were not uncommon during pediatric OLT. Our results indicated that it is useful to cannulate the femoral artery to accurately and reliably measure arterial blood pressure to detect hemodynamic instability during pediatric OLT.

The effects of prolonged inspiratory time during one-lung ventilation: a randomised controlled trial

We evaluated the effects of a prolonged inspiratory time on gas exchange in subjects undergoing one-lung ventilation for thoracic surgery. One hundred patients were randomly assigned to Group I:E = 1:2 or Group I:E = 1:1. Arterial blood gas analysis and respiratory mechanics measurements were performed 10 min after anaesthesia induction, 30 and 60 min after initiation of one-lung ventilation, and 15 min after restoration of conventional two-lung ventilation. The mean (SD) ratio of the partial pressure of arterial oxygen to fraction of inspired oxygen after 60 min of one-lung ventilation was significantly lower in Group I:E = 1:2 compared with Group I:E = 1:1 (27.7 (13.2) kPa vs 35.2 (22.1) kPa, respectively, p = 0.043). Mean (SD) physiological dead space-to-tidal volume ratio after 60 min of one-lung ventilation was significantly higher in Group I:E = 1:2 compared with Group I:E = 1:1 (0.46 (0.04) vs 0.43 (0.04), respectively, p = 0.008). Median (IQR [range]) peak inspiratory pressure was higher in Group I:E = 1:2 compared with Group I:E = 1:1 after 60 min of one-lung ventilation (23 (22-25 [18-29]) cmH2O vs 20 (18-21 [16-27]) cmH2O, respectively, p < 0.001) and median (IQR [range]) mean airway pressure was lower in Group I:E = 1:2 compared with Group I:E = 1:1 (10 (8-11 [5-15]) cmH2O vs 11 (10-13 [5-16]) cmH2O, respectively, p < 0.001). We conclude that, compared with an I:E ratio of 1:2, an I:E ratio of 1:1 resulted in a modest improvement in oxygenation and decreased shunt fraction during one-lung ventilation.

Patterns of pncA mutations in drug-resistant Mycobacterium tuberculosis isolated from patients in South Korea

BACKGROUND

Pyrazinamide (PZA), one of the most effective anti-tuberculosis drugs, becomes toxic to Mycobacterium tuberculosis when converted to pyrazinoic acid by pyrazinamidase (PZase). PZA resistance is caused mainly by the loss of enzyme activity by mutation.

OBJECTIVE

To investigate the patterns of pncA mutations in PZA-resistant mycobacteria isolated from South Korean patients.

METHODS

Mycobacterial isolates with clinically proven drug resistance were cultured to determine susceptibility to anti-tuberculosis agents. pncA mutations were recognised by sequencing and compared with the relevant wild-type DNA sequence.

RESULTS

Among 108 isolates, 102 were successfully cultured and underwent drug susceptibility testing; all were multidrug-resistant (MDR). pncA mutations were found in 86 cultured isolates (85.1%): 55 (84.6%) in MDR and 31 (86.1%) in extensively drug-resistant isolates. Substitution of a single nucleotide was most common. The most frequent mutations were a deletion that caused a frameshift at nucleotide (nt) 71, a substitution at nt 403 and a substitution at nt 11. Combined, these accounted for ≈ 40% of all mutations. However, 15 samples (14.9%) with defective PZase activity showed no mutation.

CONCLUSION

pncA mutation in M. tuberculosis is a major mechanism of PZA resistance in MDR isolates from patients in South Korea. The patterns of mutation might be more scattered and diverse. DNA-based diagnosis of PZA resistance has potential for the rapid detection of drug resistance.

Development of novel ibuprofen-loaded solid dispersion with enhanced bioavailability using cycloamylose

To develop a novel ibuprofen-loaded solid dispersion with enhanced bioavailability using cycloamylose, it was prepared using spray-drying techniques with cycloamylose at a weight ratio of 1:1. The effect of cycloamylose on aqueous solubility of ibuprofen was investigated. The physicochemical properties of solid dispersions were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction. The dissolution and bioavailability in rats were evaluated compared with ibuprofen powder. This ibuprofen-loaded solid dispersion improved about 14-fold drug solubility. Ibuprofen was present in an unchanged crystalline state, and cycloamylose played the simple role of a solubilizing agent in this solid dispersion. Moreover, the dispersion gave 2-fold higher AUC (area under the drug concentration-time curve) value compared with a ibuprofen powder, indicating that it improved the oral bioavailability of ibuprofen in rats. Thus, the solid dispersion may be useful to deliver ibuprofen with enhanced bioavailability without crystalline change.

Elevated levels of macrophage migration inhibitory factor in women with metabolic syndrome

Metabolic syndrome is a complex clinical disorder characterized by obesity, a disturbance of glucose metabolism, dyslipidemia, and hypertension, leading to increased cardiovascular risk. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine produced both by innate immune cells and by adipocytes, and it plays an important role in inflammatory and cardiovascular diseases. The goal of this study was to evaluate the expression of circulating MIF in patients with metabolic syndrome. A study was conducted involving 172 persons who attended the Jeju National University Hospital Health Promotion Center. Among the 172 subjects, 88 patients with metabolic syndrome and 84 healthy control subjects were included. Serum MIF levels were considerably higher in patients with metabolic syndrome than in healthy subjects (mean±SEM, 1413.0-pg/ml±102.6 vs. 1077.0-pg/ml±-91.3, p=0.016). Among the metabolic syndrome patients, MIF levels were significantly increased in women (1403.0-pg/ml±114.2 vs. 921.3 pg/ml±117.3, p=0.005), but not in men. Even after further linear regression adjustment for age and body mass index, the expression of MIF for women with metabolic syndrome was still clearly elevated when compared to healthy subjects (p=0.011). Circulating MIF concentrations showed a gender disparity between healthy and metabolic syndrome subjects. An elevation of systemic MIF in women with metabolic syndrome may contribute to pathogenesis of metabolic syndrome or to the development of metabolic syndrome-related diseases, such as atherosclerosis and type 2 diabetes mellitus.

Detection of antigenic proteins expressed by lymphocystis virus as vaccine candidates in olive flounder, Paralichthys olivaceus (Temminck & Schlegel)

Although the major capsid proteins (MCPs) of lymphocystis disease virus (LCDV) have been characterized, little is known about the host-derived immune response to MCPs and other LCDV antigenic proteins. To identify antigenic proteins of LCDV that could be used as vaccine candidates in olive flounder, Paralichthys olivaceus, we analysed the viral proteins responsible for its virulence by applying immuno-proteomics. LCDV proteins were separated by one-dimensional gel electrophoresis, transferred to polyvinylidene difluoride membrane, and probed with homogeneous P. olivaceus antisera elicited by LCDV natural infection and vaccination with formalin-killed LCDV. Four immune-reactive proteins were obtained at 68-, 51-, 41- and 21 kDa using antisera collected from natural infection while two proteins at 51- and 21 kDa exhibited response to antisera from vaccinated fish, indicating that the latter two proteins have vaccine potential. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoelectrospray MS/MS, the 51 and 21 kDa proteins were identified as MCP and an unknown protein, respectively.

Barley intake induces bile acid excretion by reduced expression of intestinal ASBT and NPC1L1 in C57BL/6J mice

To investigate the hypocholesterolemic mechanism of barley in vivo, six-week-old C57BL/6J mice were fed a high-fat diet (HFD) or high-fat diet containing barley (HFD-B) for seven weeks. Total and LDL cholesterol concentrations were significantly reduced in the HFD-B group while fecal cholesterol and bile acid was increased. Real-time PCR and immunoblot analysis revealed the induction of FXR expression, which in turn suppressed the expression of ASBT and NPC1L1 in the HFD-B group compared with the controls. In the liver, the expression of HMG-CoA reductase was significantly reduced while LDL receptor expression was unaltered in the HFD-B group compared with the controls. Our data suggest that the hypocholesterolemic effects of barley are primarily the result of reduced dietary cholesterol uptake and bile acid resorption. Reduced expression of intestinal ASBT and NPC1L1 may play a key role in the regulation of dietary cholesterol and bile acid metabolism in mice consuming a diet containing barley.

Identification of a naturally-occurring 8-[alpha-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]daidzein from cultivated kudzu root

INTRODUCTION

Kudzu root (Radix puerariae) is a rich source of isoflavones that are effective in preventing osteoporosis, heart disease and symptoms associated with menopause. The major isoflavonoids in kudzu root extracts were reported as puerarin, daidzin and daidzein. Recently, an unknown isoflavonoid (compound 1) was detected from one-year-old kudzu root cultivated in Vietnam.

OBJECTIVE

To identify a novel compound 1 in kudzu root extract and determine the structure of the compound by ESI(+) TOF MS-MS, (1)H-, (13)C-NMR and enzymatic hydrolysis.

METHODOLOGY

Samples were prepared by extraction of one-year-old kudzu root with 50% ethanol and the isoflavonoids were purified using recycling preparative HPLC. Unknown compound 1 was detected using UV-light at 254 nm in TLC and HPLC analyses. The molecular weight of 1 was determined using a TOF mass spectrometer equipped with an electrospray ion source. The structure of 1 was determined from the (13)C and (1)H NMR spectra recorded at 100.40 and 400.0 MHz, respectively.

RESULTS

ESI(+) TOF MS-MS analysis shows that 1 is a puerarin diglycoside. The interglycosidic linkage of diglycoside determined by (1)H-, (13)C-NMR, and enzymatic hydrolysis suggests that 1 has a glucosyl residue linked to puerarin by an alpha-1,6-glycosidic bond. This compound is the first naturally-occurring 8-[alpha-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]daidzein in kudzu root. The concentration of glucosyl-alpha-1,6-puerarin in kudzu root was 2.3 mg/g as determined by HPLC.

CONCLUSION

The results indicate that puerarin diglycoside is one of the major isoflavonoids in kudzu root and has a significant impact on the preparation of highly water-soluble glycosylated puerarin.