583 results on '"Murakami, Toshiyuki"'
Search Results
552. Hepatoprotective and nitric oxide production inhibitory activities of coumarin and polyacetylene constituents from the roots of Angelica furcijuga
- Author
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Matsuda, Hisashi, Murakami, Toshiyuki, Kageura, Tadashi, Ninomiya, Kiyofumi, Toguchida, Iwao, Nishida, Norihisa, and Yoshikawa, Masayuki
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- 1998
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553. ChemInform Abstract: Medicinal Foodstuffs. Part 19. Absolute Stereostructures of Canavalioside, a New Ent‐Kaurane‐Type Diterpene Glycoside, and Gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, New Acylated Flavonol Glycosides, from Sword Bean, the Seeds of Canavalia gladiata.
- Author
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Murakami, Toshiyuki, Kohno, Kentarou, Kishi, Akinobu, Matsuda, Hisashi, and Yoshikawa, Masayuki
- Abstract
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
- Published
- 2001
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554. ChemInform Abstract: Bioactive Saponins and Glycosides. Part 14. Structure Elucidation and Immunological Adjuvant Activity of Novel Protojujubogenin Type Triterpene Bisdesmosides, Protojujubosides A, B, and B1, from the Seeds of Zizyphus jujuba var. spinosa (Zizyphi Spinosi Semen).
- Author
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Matsuda, Hisashi, Murakami, Toshiyuki, Ikebata, Akira, Yamahara, Johji, and Yoshikawa, Masayuki
- Abstract
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
- Published
- 2000
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- View/download PDF
555. ChemInform Abstract: Structures of New Acylated Oleanene‐Type Triterpene Oligoglycosides, Theasaponins E1and E2, from the Seeds of Tea Plant, Camellia sinensis (L.) O. KUNTZE.
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Kitagawa, Isao, Hori, Kazuyuki, Motozawa, Tomohisa, Murakami, Toshiyuki, and Yoshikawa, Masayuki
- Abstract
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
- Published
- 1999
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556. Relationship between adjuvant activity and amphipathic structure of soyasaponins
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Oda, Kenji, Matsuda, Hisashi, Murakami, Toshiyuki, Katayama, Shigeji, Ohgitani, Toshiaki, and Yoshikawa, Masayuki
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SAPONINS , *IMMUNOGLOBULINS - Abstract
A correlation between adjuvant activity and amphipathic structure of saponin was first demonstrated on an experimental basis using structurally consecutive analogues. To clarify the physicochemical factors regulating the adjuvanticity of saponin, we compared the profile of the antibody response against chicken ovalbumin (OVA) in mice and hydrophile–lipophile balance (HLB) of eight purified soyasaponins. Soyasaponins bearing sugar chain(s) showed adjuvanticity stimulating anti-OVA total-IgG and IgG1 antibody responses, while their corresponding aglycones soyasapogenols A and B, did not. Among bisdesmosidic soyasaponins, soyasaponin A1 (HLB: 26.9) with a long sugar side chain induced stronger total-IgG and IgG1 antibody responses than soyasaponin A2 (HLB: 21.4). For monodesmosidic soyasaponins, the ranking in terms of antibody response was soyasaponin I (which has the highest HLB value (13.6) among the monodesmosidic soyasaponins) > soyasaponin II (HLB: 12.2) > soyasaponin III (HLB: 10.0). The adjuvant activity increased with the HLB value. The length, the number, and the composition of sugar side chains affecting the HLB value would give the overall conformation of each saponin molecule, and the amphipathic structure may define the fundamental adjuvanticity of saponins. [Copyright &y& Elsevier]
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- 2003
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557. Selection of Required Controller for Position- and Force-Based Task in Motion Copying System.
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Okano, Toshiaki, Oboe, Roberto, Ohnishi, Kouhei, and Murakami, Toshiyuki
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ELECTRIC controllers , *ROBOT motion , *HUMAN-robot interaction , *HUMAN reproduction , *TASK performance - Abstract
With the remarkable development of related technologies, the number of robots has been gradually increasing and their presence is becoming much more familiar in our daily lives. The motion copying system (MCS) is utilized as the method for conducting some tasks by robots. This system enables tasks to be reproduced when the environmental conditions are not changed. The task reproduction performance is degraded when environmental variations occur, and human-like adaptable motion is expected to be developed in the MCS. This study reveals the dominant element of motion, and the control strategy is varied at each time in each axis by considering the task realization. The flexibility of motion is learned from both the operator and the task implementation. The task reproduction experiments by MCS are conducted to verify the effectiveness of the proposal. [ABSTRACT FROM AUTHOR]
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- 2020
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558. Simultaneous bipedal locomotion based on haptics for teleoperation.
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Prasanga, D. Kasun, Tanida, Kazuki, Ohnishi, Kouhei, and Murakami, Toshiyuki
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BIPEDALISM , *REMOTE control , *CENTER of mass , *AUTONOMOUS robots , *ROBOTIC exoskeletons , *GAIT in humans , *DYNAMIC models , *WALKING - Abstract
This paper proposes a novel, simultaneous bipedal locomotion method using haptics for remote operation of biped robots. In general, traditional biped walking methods require very high computational power and advanced controllers to perform the required task. However, in this proposed method, a master exoskeleton attached to the human's lower body is used to obtain the trajectory and haptic information to generate the trajectory of the slave biped robot in real time. Lateral motion of the center of mass of the biped is constrained in this experiment. Also, it is considered that no communication delay is presented in between the two systems in this experiment, and they are not discussed in this paper. Since a direct motion transmission is used in the proposed method, this method is quite straight forward and a simultaneous walking can be realized at the same time with high performance. Also, it does not require an exact dynamic model of the biped or specific method to plan the trajectory. The gait pattern of the biped is directly determined by that of the human. Also, the operator can feel the remote environment through the exoskeleton robot. Results obtained from the experiments validate the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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559. A new single-reference quantitative method using liquid chromatography with relative molar sensitivity based on 1H-qNMR for khellactone esters from Peucedanum japonicum root extract.
- Author
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Iwasaki, Daigo, Kanazawa, Mai, Kawamoto, Fusako, Araho, Daisuke, Murakami, Toshiyuki, Nishizaki, Yuzo, Masumoto, Naoko, and Sugimoto, Naoki
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LIQUID chromatography , *SILICA gel , *ESTERS , *QUANTITATIVE research , *FOOD quality , *QUALITY assurance - Abstract
[Display omitted] • A single-reference method was proposed to quantify khellactone esters. • A common single-reference was set up for six khellactone esters. • The quantification method was validated using RMS based on 1H-qNMR. • It is the first RMS method to be evaluated for use on conventional LC and UHPLC. Khellactone ester (KLE) quantification using the absolute calibration method is difficult owing to the unavailability of standard reagents that can guarantee purity. Herein, a new method was developed to quantify KLEs from Peucedanum japonicum root extracts using liquid chromatography (LC) without utilizing standards. This method used relative molar sensitivity (RMS) and 7-ethoxy-4-methylcoumarin as a single-reference (SR) compound instead of KLE standards. RMS is the sensitivity ratio of SR to analytes, determined using an offline combination of quantitative NMR and LC. LC was performed using a triacontylsilyl silica gel column of superficially porous particles with a ternary mobile phase. The range of the method was 2.60–509 µmol/L. The accuracy and precision were reasonable. This is the first study to apply the RMS method to both conventional LC and ultra-high-performance liquid chromatography using the same mobile phase and column. This method may aid the quality assurance of foods containing KLEs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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560. Early onset of PRES in a patient with a subarachnoid haemorrhage due to a ruptured intracranial aneurysm.
- Author
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Kuroda, Hiroki, Kashimura, Hiroshi, Murakami, Toshiyuki, Endo, Hidehiko, Mase, Tomohiko, and Ogasawara, Kuniaki
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SUBARACHNOID hemorrhage , *INTRACRANIAL aneurysms , *CEREBRAL vasospasm , *MAGNETIC resonance imaging , *HYPERTENSION - Abstract
Posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid haemorrhage (SAH). We present a case involving a patient who developed PRES, prior to induction of hypertensive therapy, 2 days after the onset of a SAH due to a ruptured intracranial aneurysm. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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561. Apparent brain temperature imaging with multi-voxel proton magnetic resonance spectroscopy compared with cerebral blood flow and metabolism imaging on positron emission tomography in patients with unilateral chronic major cerebral artery steno-occlusive disease
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Nanba, Takamasa, Nishimoto, Hideaki, Yoshioka, Yoshichika, Murakami, Toshiyuki, Sasaki, Makoto, Uwano, Ikuko, Fujiwara, Shunrou, Terasaki, Kazunori, and Ogasawara, Kuniaki
- Abstract
Purpose: The purpose of the present study was to determine whether apparent brain temperature imaging using multi-voxel proton magnetic resonance (MR) spectroscopy correlates with cerebral blood flow (CBF) and metabolism imaging in the deep white matter of patients with unilateral chronic major cerebral artery steno-occlusive disease. Methods: Apparent brain temperature and CBF and metabolism imaging were measured using proton MR spectroscopy and O-positron emission tomography (PET), respectively, in 35 patients. A set of regions of interest (ROIs) of 5 × 5 voxels was placed on an MR image so that the voxel row at each edge was located in the deep white matter of the centrum semiovale in each cerebral hemisphere. PET images were co-registered with MR images with these ROIs and were re-sliced automatically using image analysis software. Results: In 175 voxel pairs located in the deep white matter, the brain temperature difference (affected hemisphere − contralateral hemisphere: ΔBT) was correlated with cerebral blood volume (CBV) ( r = 0.570) and oxygen extraction fraction (OEF) ratios (affected hemisphere/contralateral hemisphere) ( r = 0.641). We excluded voxels that contained ischemic lesions or cerebrospinal fluid and calculated the mean values of voxel pairs in each patient. The mean ΔBT was correlated with the mean CBF ( r = − 0.376), mean CBV ( r = 0.702), and mean OEF ratio ( r = 0.774). Conclusions: Apparent brain temperature imaging using multi-voxel proton MR spectroscopy was correlated with CBF and metabolism imaging in the deep white matter of patients with unilateral major cerebral artery steno-occlusive disease. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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562. A Dynamical Approach to Force Control without Force Sensor
- Author
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Murakami, Toshiyuki, Yu, Fangming, and Ohnishi, Kouhei
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- 1993
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563. Brain temperature measured by H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning.
- Author
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Beppu, Takaaki, Fujiwara, Shunrou, Nishimoto, Hideaki, Murakami, Toshiyuki, Ogawa, Akira, Ogasawara, Kuniaki, Yoshioka, Yoshichika, and Matsuda, Tsuyoshi
- Abstract
Introduction: Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the 'heat-removal' theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using H-magnetic resonance spectroscopy (MRS). Methods: Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases ( p < 0.05) in CO-poisoned patients. Results: BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909). Conclusions: The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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564. Blood Pressure-Depressing Activity of a Peptide Derived from Silkworm Fibroin in Spontaneously Hypertensive Rats.
- Author
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Igarashi, Kiharu, Yoshioka, Kosuke, Mizutani, Kenji, Masazumi Miyakoshi, Murakami, Toshiyuki, and Toshifumi Akizawa
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SILKWORMS , *PEPTIDES , *ANGIOTENSIN converting enzyme , *TRYPTOPHAN , *TYROSINE , *PHENYLALANINE - Abstract
The article presents a scientific study that investigates peptides which showed inhibitory activity against the angiotensin I-converting enzyme (ACE) from silkworm fibroin in spontaneously hypertensive rats and its blood pressure depressing activity. Results of the study suggested that aromatic amino acid residues like tryptophan, tyrosine and phenylalanine at the C-terminal of peptides, which has a blood pressure depressing effect, bind with the active site of angiotensin I-converting enzyme.
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- 2006
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565. Guest Editorial.
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Oboe, Robert, Bogosyan, Seta, Iwasaki, Makoto, and Murakami, Toshiyuki
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FRICTION , *INDUSTRIAL robots - Abstract
The article various reports published within the issue, including one on high-performance and high-precision control, on the effects of friction and backlash in relation to high performance in MC, and on a method in improving the walking stability of a biped robot.
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- 2009
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566. A Method of Predicting Posture-related Pain Using Biomechanical Parameters for Patients with Lumbar Spinal Disc Herniation.
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Hatsushiro A, Tawaki Y, and Murakami T
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- Humans, Pain etiology, Lumbar Vertebrae, Lower Extremity, Lumbosacral Region, Intervertebral Disc Displacement complications, Intervertebral Disc Displacement diagnosis
- Abstract
Lumbar spinal disc herniation is a disease in which the protruding nucleus pulposus presses on the nerve due to actions that place loads on the disc, causing pain in the lower back and lower limbs. About 80% of treatments of disc herniation are conservative treatments, and although it is necessary to live with pain for a long time, there have been no studies that clearly define the relationship between pain and biomechanical parameters. In this study, we proposed a method of identifying biomechanical parameters that predict posture-related pain in patients with lumbar spinal disc herniation. The pain values were quantitatively evaluated by the Numerical Rating Scale (NRS) and the biomechanical parameters were analyzed by OpenSim. Lasso regression was performed to narrow down the biomechanical parameters that were related to pain and derive the mathematical model of the relationship. Therefore, many of the parameters of the obtained mathematical model were related to the lumbar spine and were consistent with areas that be related to lumbar spinal disc herniation.
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- 2023
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567. Classification of Older and Fall-Experienced Subjects by Postural Sway Data Using Mass Spring Damper Model.
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Tawaki Y, Nishimura T, and Murakami T
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- Adolescent, Aged, Aging, Algorithms, Humans, Postural Balance, Posture
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The quiet standing test is used to detect diseases of the postural control system. The descriptive statistics of the center of pressure (COP) of older people during the test tend to be larger than those of healthy young people, but they cannot indicate structural problems in postural control. COP trajectories can be mathematically modeled with structural parameters such as viscosity, stiffness, and stochastic terms; however, the classification accuracy of older and fall-experienced people using such parameters has not been sufficiently verified. In this study, six structural parameters of a mass-spring-damper (MSD) model were estimated using two datasets, in which a total of 212 subjects performed quiet standing tests under four conditions. The estimated parameters were used for classification with a random forest algorithm to examine the differences in classification accuracy compared to seven conventional descriptive statistics methods. For the classification of older subjects, the classification accuracy of the MSD parameter method was the highest in foam condition, with positive likelihood ratios approximately 8.0. For the classification of fall-experienced subjects, the positive likelihood ratio of the MSD parameter method was 5.0, which is better than conventional descriptive statistics. Various MSD parameters revealed that aging and changing the floor surface and visual conditions cause oscillations in the COP behavior. While the MSD parameters were confirmed to help classify older subjects more accurately than the conventional descriptive statistics, there was room for further improvement in the classification accuracy of fall-experienced subjects.
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- 2022
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568. A multi-sensory dataset for the activities of daily living.
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Ruzzon M, Carfì A, Ishikawa T, Mastrogiovanni F, and Murakami T
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The article describes a multi-sensory dataset related to the Activities of Daily Living (ADL). These are the activities that contribute to an assessment of the overall status of elderly or people with special needs, possibly suffering from mild cognitive impairments. Typical basic ADLs include walking, such postural transitions as getting up or sitting down, as well as behaviours related to feeding, such as drinking or eating with knife and fork, or personal hygiene, e.g., teeth brushing. The collection process adopted for building this dataset considers nine ADL-related activities, which have been performed in different locations and involving the usage of both left and right arms. The dataset acquisition involved 10 volunteers performing 186 ADL instances, for a grand total of over 1860 examples. The dataset contains data from six 9-axis Inertial Measurement Units (IMUs), worn by each volunteer (two for each arm, one on the back and one on the right thigh). The dataset features an accurate data labelling done via manual annotation performed thanks to videos recorded by an RGB camera. The videos recorded during the experiments have been used only for labelling purposes, and they are not published., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article., (© 2020 The Authors.)
- Published
- 2020
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569. Improving quality control of yucca extracts used as food additives by screening antimicrobial activity using NMR metabolomics.
- Author
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Suzuki R, Ohno H, Murakami T, and Shirataki Y
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- Animals, Anti-Infective Agents chemistry, Chromatography, High Pressure Liquid methods, Food Additives chemistry, Food Preservation methods, Magnetic Resonance Spectroscopy, Metabolomics, Mexico, Plant Extracts chemistry, Principal Component Analysis, Quality Control, Saponins chemistry, Anti-Infective Agents pharmacology, Food Additives pharmacology, Food Preservatives pharmacology, Plant Extracts pharmacology, Yucca chemistry
- Abstract
Yucca schidigera is mainly distributed in southwestern US and the northern desert of Mexico. Its extract is widely used as a food additive for its antimicrobial activity. However, this antimicrobial activity is subject to significant variability across production lots. Yucca extracts are natural products and their composition is affected by their cultivation area and weather. Manufacturer deal with natural products such as food additives pay particularly close attention to quality control. In the present study, NMR metabolomics methods were used to screen the antimicrobial activity of yucca extracts. Yucca extracts were subjected to principal component analysis (PCA) and categorized on a score plot of their
1 H NMR spectral data according to their antimicrobial activity. Furthermore, hierarchical cluster analysis (HCA) was also used to classify yucca extracts based on their antimicrobial activity. Classification using PCA and HCA was dependent upon saponin content, particularly that of schidigera-saponin A1 and D1, which was further confirmed by HPLC analysis of the yucca extracts. We demonstrated that NMR-based metabolomics is a potentially useful tool to use in combination with conventional quality control methods for yucca extracts used as food additives. We envisage this method as tool for initially screening the extracts prior to carrying out the officially recommended quality control tests.- Published
- 2020
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570. Evaluation of Langevin Model for Human Stabilogram Based on Reproducibility of Statistical Indicators.
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Tawaki Y and Murakami T
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- Humans, Models, Theoretical, Reproducibility of Results, Stochastic Processes, Movement, Postural Balance, Posture
- Abstract
Fall risk is a serious problem especially for the elderly. Fall accident causes fracture, and it leads to bedridden. Early detection of balance inability and rehabilitation training is important to decrease the risk. Quiet standing test is one of the physical tests to assess the balance inability of human. When the human is standing, he/she controls the plantar force to keep the balance. Center of pressure (COP) is the representative parameter to explain the plantar force movement. During the quiet standing test, COP fluctuates unconsciously. There are many researches that analyze the relationship between the COP fluctuation and balance inability. Many statistical indicators have been developed to assess the fluctuation specification.In contrast, several researchers have been tried to reveal the COP fluctuation mechanism by introducing stochastic mathematical model. Ornstein-Uhlenbeck process and diffusion equation are often introduced to the model. The mathematical models have been developed, and analyzed how visual input is related to the model parameters. If the mathematical model can explain the COP fluctuation completely, it becomes easier to assess the balance ability by comparing the model parameters.However, statistical indicators are still used in the clinical cases, thus there is room to discuss which statistical indicators to be used for assessment. The purpose of this research is to explore the relationship between statistical indicators and numerical model by evaluating whether the numerical model reproduces the same values with real data. The reproduced indicators and original indicators are compared, and the magnitude of the errors are evaluated.
- Published
- 2019
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571. New ellagitannins from Tiencha and their inhibitory activity against dental plaque.
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Nakano F, Miyoshi S, and Murakami T
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- Hydrolyzable Tannins chemistry, Hydrolyzable Tannins isolation & purification, Molecular Structure, Plant Extracts chemistry, Plant Leaves chemistry, Dental Plaque, Hydrolyzable Tannins pharmacology, Plant Extracts pharmacology, Rubus chemistry
- Abstract
Four new galloyl-oxygen-diphenyl (GOD)-type ellagitannins, brambliins A-D (1-4), were isolated from the leaves of Rubus suavissimus. Their structures were elucidated by extensive spectroscopic analyses and the absolute configurations of 1-4 were determined by chemical and phytochemical evidence. These GOD-type ellagitannins inhibited the formation of dental plaque, which is beneficial for oral hygiene.
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- 2017
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572. Oxygen extraction fraction measurement using quantitative susceptibility mapping: Comparison with positron emission tomography.
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Kudo K, Liu T, Murakami T, Goodwin J, Uwano I, Yamashita F, Higuchi S, Wang Y, Ogasawara K, Ogawa A, and Sasaki M
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- Adult, Aged, Brain blood supply, Carotid Stenosis metabolism, Carotid Stenosis physiopathology, Cerebrovascular Circulation physiology, Female, Humans, Infarction, Middle Cerebral Artery metabolism, Infarction, Middle Cerebral Artery physiopathology, Male, Middle Aged, Oxygen Consumption physiology, Young Adult, Brain diagnostic imaging, Brain Mapping methods, Carotid Stenosis diagnostic imaging, Infarction, Middle Cerebral Artery diagnostic imaging, Magnetic Resonance Imaging methods, Oxygen analysis, Positron-Emission Tomography methods
- Abstract
The purposes of this study are to establish oxygen extraction fraction (OEF) measurements using quantitative susceptibility mapping (QSM) of magnetic resonance imaging (MRI), and to compare QSM-OEF data with the gold standard (15)O positron emission tomography (PET). Twenty-six patients with chronic unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, and 15 normal subjects were included. MRI scans were conducted using a 3.0 Tesla scanner with a three-dimensional spoiled gradient recalled sequence. QSM images were created using the morphology-enabled dipole inversion method, and OEF maps were generated from QSM images using extraction of venous susceptibility induced by deoxygenated hemoglobin. Significant correlation of relative OEF ratio to contra-lateral hemisphere between QSM-OEF and PET-OEF was observed (r = 0.62, p < 0.001). The local (intra-section) correlation was also significant (r = 0.52, p < 0.001) in patients with increased PET-OEF. The sensitivity and specificity of OEF increase in QSM was 0.63 (5/8) and 0.89 (16/18), respectively, in comparison with PET. In conclusion, good correlation was achieved between QSM-OEF and PET-OEF in the identification of elevated OEF in affected hemispheres of patients with unilateral chronic steno-occlusive disease., (© The Author(s) 2015.)
- Published
- 2016
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573. Brain temperature measured by 1H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning.
- Author
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Fujiwara S, Yoshioka Y, Matsuda T, Nishimoto H, Murakami T, Ogawa A, Ogasawara K, and Beppu T
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- Adult, Aged, Humans, Hydrogen, Male, Middle Aged, Body Temperature, Brain physiopathology, Carbon Monoxide Poisoning diagnosis, Magnetic Resonance Spectroscopy methods
- Abstract
Introduction: Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the "heat-removal" theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using (1)H-magnetic resonance spectroscopy (MRS)., Methods: Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases (p < 0.05) in CO-poisoned patients., Results: BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909)., Conclusions: The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature.
- Published
- 2016
- Full Text
- View/download PDF
574. Microsurgical clipping for the true posterior communicating artery aneurysm in the distal portion of the posterior communicating artery.
- Author
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Takeda M, Kashimura H, Chida K, and Murakami T
- Abstract
Background: Aneurysms arising from the posterior communicating artery (PCoA) itself are rare in which aneurysms usually located in the proximal portion of the PCoA. The authors report a case of the true PCoA ruptured aneurysm in the distal portion of the PCoA., Case Description: The patient was an 83-year-old man who suffered subarachnoid hemorrhage. Cerebral angiography revealed a saccular aneurysm arising on the fetal type right PCoA itself in the distal portion of the PCoA. 2 days after the onset of symptoms, the patient underwent right interfascial pterional craniotomy, with anterior temporal approach. The aneurysm was successfully clipped with the preservation of both the PCoA and the thalamoperforating artery., Conclusion: We speculated that blood flow into the PCoA gradually increased after occlusion of the left vertebral artery, which induced tortuosity of the PCoA. As a result, hemodynamic stress might increase near the curvature and cause aneurysm formation.
- Published
- 2015
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575. Postoperative increase in cerebral white matter fractional anisotropy on diffusion tensor magnetic resonance imaging is associated with cognitive improvement after uncomplicated carotid endarterectomy: tract-based spatial statistics analysis.
- Author
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Sato Y, Ito K, Ogasawara K, Sasaki M, Kudo K, Murakami T, Nanba T, Nishimoto H, Yoshida K, Kobayashi M, Kubo Y, Mase T, and Ogawa A
- Subjects
- Aged, Anisotropy, Brain surgery, Carotid Stenosis complications, Cognition Disorders etiology, Diffusion Magnetic Resonance Imaging, Diffusion Tensor Imaging, Endarterectomy, Carotid, Female, Humans, Image Interpretation, Computer-Assisted, Male, Middle Aged, Neuropsychological Tests, Brain pathology, Carotid Stenosis surgery, Cognition Disorders surgery, Nerve Fibers, Myelinated pathology
- Abstract
Background: Carotid endarterectomy (CEA) might improve cognitive function. Fractional anisotropy (FA) values in the cerebral white matter derived from diffusion tensor magnetic resonance imaging (DTI) correlate with cognitive function in patients with various central nervous system diseases., Objective: To use tract-based spatial statistics to determine whether postoperative changes of FA values in the cerebral white matter derived from DTI are associated with cognitive improvement after uncomplicated CEA., Methods: In 80 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), FA values in the cerebral white matter were derived from DTI before and 1 month after surgery and were analyzed by using tract-based spatial statistics. Neuropsychological testing, consisting of the Wechsler Adult Intelligence Scale Revised, the Wechsler Memory Scale and the Rey-Osterreith Complex Figure test, was also performed preoperatively and after the first postoperative month., Results: Based on the neuropsychological assessments, 11 (14%) patients were defined as having postoperatively improved cognition. The difference between the 2 mean FA values (postoperative values minus preoperative values) in the cerebral hemisphere ipsilateral to surgery was significantly associated with postoperative cognitive improvement (95% confidence intervals, 2.632-9.877; P = .008). White matter FA values in patients with postoperative cognitive improvement were significantly increased after surgery in the whole ipsilateral cerebral hemisphere, in the contralateral anterior cerebral artery territory, and in the watershed zone between the contralateral anterior and middle cerebral arteries., Conclusion: Postoperative increase in cerebral white matter FA on DTI is associated with cognitive improvement after uncomplicated CEA.
- Published
- 2013
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576. Changes in cognitive function after carotid endarterectomy in older patients: comparison with younger patients.
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Takahashi Y, Ogasawara K, Matsumoto Y, Kobayashi M, Yoshida K, Kubo Y, Beppu T, Murakami T, Nanba T, and Ogawa A
- Subjects
- Age Factors, Aged, Cognition Disorders psychology, Female, Humans, Japan, Male, Middle Aged, Neuropsychological Tests statistics & numerical data, Postoperative Complications psychology, Prospective Studies, Psychometrics statistics & numerical data, ROC Curve, Reference Values, Wechsler Scales statistics & numerical data, Cognition Disorders diagnosis, Endarterectomy, Carotid, Postoperative Complications diagnosis
- Abstract
Objective and subjective assessments of changes in cognition after carotid endarterectomy (CEA) were compared between older patients (≥76 years old) and younger patients (<76 years old). Patients underwent subjective cognitive assessment by a neurosurgeon and the patient's next of kin, and neuropsychological testing (five parameters) before and after surgery. Of 37 older patients studied, 4 (11%), 28 (75%), and 5 (14%) patients were defined as having subjectively improved, unchanged, and impaired cognition, respectively, following surgery. Differences in test scores (postoperative test score - preoperative test score: Δ score) in all neuropsychological tests were significantly lower in the older patients than in the 213 younger patients. The Δ score was able to statistically differentiate older patients with subjectively improved, unchanged, and impaired cognition after surgery. Receiver operating characteristic analysis showed that the Δ score cut-off point for detecting subjective improvement (upper cut-off point) and impairment (lower cut-off point) in cognition after surgery in older patients was identical to the mean or the mean +0.5 standard deviation (SD) and the mean -1.5 SD or the mean -1 SD, respectively, of the control value obtained from normal subjects. The upper and lower cut-off points were lower and higher, respectively, than those in younger patients. In conclusion, although neuropsychological test scores reflect the subjective assessment of postoperative change in cognition in older patients, the optimal cut-off points for the test scores to detect subjective improvement and impairment in cognition after CEA are different in older patients compared with younger patients.
- Published
- 2013
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577. Brain temperature measured by using proton MR spectroscopy predicts cerebral hyperperfusion after carotid endarterectomy.
- Author
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Murakami T, Ogasawara K, Yoshioka Y, Ishigaki D, Sasaki M, Kudo K, Aso K, Nishimoto H, Kobayashi M, Yoshida K, and Ogawa A
- Subjects
- Aged, Aged, 80 and over, Blood Volume, Chi-Square Distribution, Female, Humans, Male, Middle Aged, Predictive Value of Tests, Protons, ROC Curve, Risk Factors, Sensitivity and Specificity, Statistics, Nonparametric, Tomography, Emission-Computed, Single-Photon, Body Temperature, Carotid Stenosis surgery, Cerebrovascular Circulation physiology, Endarterectomy, Carotid adverse effects, Magnetic Resonance Spectroscopy methods
- Abstract
Purpose: To determine whether brain temperature measured by using preoperative proton magnetic resonance (MR) spectroscopy could help identify patients at risk for cerebral hyperperfusion after carotid endarterectomy (CEA)., Materials and Methods: Institutional review board approval and informed consent were obtained. Acquisition of proton MR spectroscopic data by using point-resolved spectroscopy without water suppression was performed before CEA in the bilateral cerebral hemispheres of 84 patients with unilateral internal carotid artery stenosis (> or =70%) and without contralateral internal carotid artery steno-occlusive disease. Brain temperature was calculated from the chemical shift difference between water and N-acetylaspartate signals at proton MR spectroscopy. Cerebral blood flow (CBF) was also measured by using single photon emission computed tomography and N-isopropyl-p-[(123)I]-iodoamphetamine before and immediately after CEA and on the 3rd postoperative day. The relationship between each variable and the development of post-CEA hyperperfusion (CBF increase > or = 100% compared with preoperative values) was evaluated with univariate statistical analysis followed by multivariate analysis., Results: A linear correlation was observed between preoperative brain temperature difference (the value in the affected hemisphere minus the value in the contralateral hemisphere) and increases in CBF immediately after CEA (r = 0.763 and P < .001) when the preoperative brain temperature difference was greater than 0. Cerebral hyperperfusion immediately after CEA was observed in nine patients (11%). Elevated preoperative brain temperature difference was the only significant independent predictor of post-CEA hyperperfusion. When elevated brain temperature difference was defined as a marker of hemodynamic impairment in the affected cerebral hemisphere, use of preoperative brain temperature difference resulted in 100% sensitivity and 87% specificity, with a 47% positive predictive value and a 100% negative predictive value for the prediction of post-CEA hyperperfusion. Hyperperfusion syndrome developed on the 3rd and 4th postoperative days in two of the nine patients who exhibited hyperperfusion immediately after CEA., Conclusion: Brain temperature measured by using preoperative proton MR spectroscopy may help identify patients at risk for post-CEA cerebral hyperperfusion., ((c) RSNA, 2010.)
- Published
- 2010
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578. Structures of new cucurbitane-type triterpenes and glycosides, karavilagenins and karavilosides, from the dried fruit of Momordica charantia L. in Sri Lanka.
- Author
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Nakamura S, Murakami T, Nakamura J, Kobayashi H, Matsuda H, and Yoshikawa M
- Subjects
- Glycosides isolation & purification, Molecular Conformation, Sri Lanka, Stereoisomerism, Triterpenes isolation & purification, Fruit chemistry, Glycosides chemistry, Momordica charantia chemistry, Triterpenes chemistry
- Abstract
Three new cucurbitane-type triterpene called karavilagenins A, B, and C and five new cucurbitane-type triterpene glycosides called karavilosides I, II, III, IV, and V were isolated from the dried fruit of Sri Lanka Momordica charantia L. (Cucurbitaceae) together with two known cucurbitane-type triterpenes, 19(R)-methoxy-5beta,19-epoxycucurbita-6,23-dien-3beta,25-diol and 5,19-epoxycucurbita-6,23-diene-3,25-diol, and nine known cucurbitane-type triterpene glycosides, goyaglycosides-b, -c, and -d, and momordicosides F1, F2, G, I, K, and L. The structures of karavilagenins and karavilosides were elucidated on the basis of chemical and physicochemical evidence.
- Published
- 2006
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579. Absolute stereostructures of polypodane-type triterpenes, myrrhanol A and myrrhanone A, from guggul-gum resin (the resin of Balsamodendron mukul).
- Author
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Matsuda H, Morikawa T, Ando S, Oominami H, Murakami T, Kimura I, and Yoshikawa M
- Subjects
- Magnetic Resonance Spectroscopy, Molecular Conformation, Plant Extracts chemistry, Stereoisomerism, Triterpenes isolation & purification, Commiphora, Resins, Plant chemistry, Triterpenes chemistry
- Abstract
Two new polypodane-type triterpenes, myrrhanol A and myrrhanone A, were isolated from the 50% aqueous methanolic extract of guggul-gum resin [the resin of Balsamodendron (=Commiphora) mukul HOOK]. The structures of the new constituents, including their absolute configurations, were determined on the basis of chemical and physicochemical evidence.
- Published
- 2004
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580. Absolute stereostructures of polypodane- and octanordammarane-type triterpenes with nitric oxide production inhibitory activity from guggul-gum resins.
- Author
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Matsuda H, Morikawa T, Ando S, Oominami H, Murakami T, Kimura I, and Yoshikawa M
- Subjects
- Animals, Commiphora, Macrophages enzymology, Methanol chemistry, Mice, Nitric Oxide Synthase antagonists & inhibitors, Nitric Oxide Synthase Type II, Plant Extracts pharmacology, Plant Gums, Stereoisomerism, Triterpenes isolation & purification, Nitric Oxide biosynthesis, Plant Extracts chemistry, Plants, Medicinal chemistry, Triterpenes chemistry, Triterpenes pharmacology
- Abstract
The methanolic extract from guggul-gum resin, the resin of Balsamodendron mukul, was found to inhibit nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages (IC(50) = 13 microg/mL). From the methanolic extract, three new polypodane-type triterpenes, myrrhanol B and myrrhanones B and A acetate, and a new octanordammarane-type triterpene, epimansumbinol, were isolated together with 17 known compounds including progesterone and the related steroids. The absolute stereostructures of new triterpenes were elucidated on the basis of chemical and physicochemical evidence. The several constituents showed inhibitory effects on nitric oxide production and induction of inducible nitric oxide synthase.
- Published
- 2004
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581. Oral Kohki Tea and its protective effect against in vitro ischemic damage to the bladder.
- Author
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Levin RM, Leggett RE, Whitbeck C, Murakami T, Kambara T, and Aikawa K
- Subjects
- Administration, Oral, Animals, Carbachol pharmacology, Electric Stimulation methods, Hypoxia physiopathology, Male, Muscle Contraction, Muscle, Smooth physiopathology, Potassium Chloride pharmacology, Rabbits, Urinary Bladder drug effects, Ischemia physiopathology, Tea, Urinary Bladder blood supply, Urinary Bladder physiopathology
- Abstract
Aims: Results of several studies indicate that ischemia/reperfusion (I/R) is an etiological factor in the contractile dysfunctions induced by partial bladder outlet obstruction in animal models. In support of this hypothesis, pretreatment of rabbits with Kohki Tea (Engelhardtia chrysolepis), a Japanese herbal drink very high in antioxidant activity, significantly reduced the contractile dysfunctions induced by partial outlet obstruction. The current study was designed to determine if pretreating rabbits with Kohki Tea could protect the bladder against the contractile damage induced by in vitro ischemia followed by re-oxygenation., Methods: Forty-eight New Zealand White rabbits were separated into two groups of 24; Group 1 was pretreated by oral gavage for 3 weeks with Kohki Tea and Group 2 received vehicle (water). Each rabbit was anesthetized with pentobarbital. The urinary bladder was rapidly removed and eight longitudinal muscle strips were cut from the bladder body. Each strip was mounted in a separate 15-ml bath containing Tyrode's solution with glucose (1 mg/ml) and maintained at 37 degrees C. All strips were equilibrated for 30 min with a gas mixture of 95% O2 and 5% CO2. At the end of this period of time, all strips were stimulated with field stimulation (FS) carbachol and KCl. After the last wash, the aeration was changed to hypoxic mixture (nitrogen-CO2) without glucose. At the end of 2 hr, the aeration was changed back to the normal 95% O2 and 5% CO2, and glucose was added to the buffer. After 1 hr of re-oxygenation, a second set of stimulations was performed. In order to represent hyperreflexia, the strips were stimulated at 32-Hz FS at 5-min intervals during the hypoxic period in half of the in vitro experiments., Results: The results showed that Kohki Tea pretreatment protected the bladder's response to FS from the detrimental effects of repetitive stimulation and the detrimental effects of both in vitro ischemia and repetitive stimulation on the contractile responses to carbachol and KCl., Conclusions: These data are consistent with the concept that Kohki Tea acts by protecting the bladder from cellular damage caused by hypoxia and the generation of free radicals., (Copyright 2004 Wiley-Liss, Inc.)
- Published
- 2004
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582. Characterization of new sweet triterpene saponins from Albizia myriophylla.
- Author
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Yoshikawa M, Morikawa T, Nakano K, Pongpiriyadacha Y, Murakami T, and Matsuda H
- Subjects
- Adult, Carbohydrate Sequence, Humans, Hydrolysis, Molecular Sequence Data, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Oleanolic Acid analogs & derivatives, Oleanolic Acid chemistry, Oleanolic Acid pharmacology, Saponins chemistry, Saponins pharmacology, Structure-Activity Relationship, Sweetening Agents chemistry, Sweetening Agents pharmacology, Thailand, Triterpenes chemistry, Triterpenes pharmacology, Albizzia chemistry, Oleanolic Acid isolation & purification, Plants, Edible chemistry, Saponins isolation & purification, Sweetening Agents isolation & purification, Triterpenes isolation & purification
- Abstract
Five new oleanane-type triterpene saponins, albiziasaponins A-E (1-5), were isolated from the stems of Albizia myriophylla collected in Thailand, together with two known triterpene saponins, licorice-saponin F3 and yunganoside B(1). The structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. In addition, when sensory tests were performed on sweetness, albiziasaponin B (2), with a carbonyl group at the C-30 position, was found to show a potent sweetness intensity relative to sucrose (600 times).
- Published
- 2002
- Full Text
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583. New flavonol oligoglycosides and polyacylated sucroses with inhibitory effects on aldose reductase and platelet aggregation from the flowers of Prunus mume.
- Author
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Yoshikawa M, Murakami T, Ishiwada T, Morikawa T, Kagawa M, Higashi Y, and Matsuda H
- Subjects
- Algorithms, Animals, Chromatography, High Pressure Liquid, Disaccharides chemistry, Disaccharides pharmacology, Enzyme Inhibitors chemistry, Enzyme Inhibitors pharmacology, Flavonoids chemistry, Flavonoids pharmacology, Glycosides chemistry, Glycosides pharmacology, Hydrolysis, Japan, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Rabbits, Stereoisomerism, Sucrose chemistry, Sucrose pharmacology, Aldehyde Reductase antagonists & inhibitors, Blood Platelets drug effects, Disaccharides isolation & purification, Enzyme Inhibitors isolation & purification, Flavonoids isolation & purification, Glycosides isolation & purification, Plants, Medicinal chemistry, Sucrose analogs & derivatives, Sucrose isolation & purification
- Abstract
The methanolic extract from the fresh flowers of Prunus mume exhibited inhibitory effects against aldose reductase and platelet aggregation. From the methanolic extract, two new flavonol oligoglycosides, 2' '-O-acetylrutin and 2' '-O-acetyl-3'-O-methylrutin, and two new polyacylated sucroses, prunoses I and II, were isolated together with 11 known constituents. The structures of 2' '-O-acetylrutin, 2' '-O-acetyl-3'-O-methylrutin, and prunoses I and II were determined on the basis of chemical and physicochemical evidence as quercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-2' '-O-acetyl-beta-D-glucopyranoside, 3'-O-methylquercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-2' '-O-acetyl-beta-D-glucopyranoside, 1,4,3',4',6'-penta-O-acetyl-6-O-p-coumaroylsucrose, and 1,3',4',6'-tetra-O-acetyl-6-O-p-coumaroylsucrose, respectively. The flavonol glycosides and prunose I were found to inhibit aldose reductase, while prunoses I and II inhibited platelet aggregation induced by thrombin.
- Published
- 2002
- Full Text
- View/download PDF
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