Final-Stage Site-Selective Acylation for the Total Syntheses of Multifidosides A-C.

Article first published online: 28 AUG 2015The first total syntheses of multifidosides A-C have been achieved. The synthetic strategy is characterized by catalytic site-selective acylation of unprotected glycoside precursors in the final stage of the synthesis. High functional-group tolerance of the site-selective acylation, promoted by an organocatalyst, enabled the conventionally difficult molecular transformation in a predictable and reliable manner. An advantage of this strategy is to avoid the risks of undesired side reactions during the removal of the protecting groups at the final stage of the total synthesis

Asymmetric desymmetrization of meso-diols by C(2)-symmetric chiral 4-pyrrolidinopyridines.

In this work we developed C(2)-symmetric chiral nucleophilic catalysts which possess a pyrrolidinopyridine framework as a catalytic site. Some of these organocatalysts effectively promoted asymmetric desymmetrization of meso-diols via enantioselective acylation

The changes of Auditory Evoked Potential (AEP) and EEG in the patients undergoing hemodialysis

AEP (Auditory Evoked Potential) and EEG were studied with 20 patients undergoing hemodialysis (dialyzed group, 41~65 y. o.), consisted of non-diabetic group (13 with chronic glomerulonephritis) and diabetic group (7 with diabetic nephropathy), comparing with those of 20 healthy subjects (normal group, 38~66 y. o.). EEGs containing AEPs evoked by click stimulation were recorded with 1024 msec of analysis time through the two derivations (3 CH : Cz→A1+2 and 6CH : Cz→T5). The group-mean AEPs were obtained with each group, and compared with each other, and then the differences of latencies and peak-to-peak amplitudes of the components were tested statistically between the groups. The EEGs were subjected to the quantitative frequency analysis. Correlation coefficients were tested statistically between the latencies, peak-to-peak amplitudes of AEP components and EEG power %, and between those and blood data. The following results were obtained. 1. The waveforms of group-mean AEP of normal group had hexaphasic contour, consisted of components P1~8 and N1~8, including the prominent negative peak N4 and positive peak P5, within 600 msec of latency. 2. The group-mean AEP of non-diabetic group had similar contour to that of normal group. Latencies of the components were significantly longer except for that of P5, and peak-to-peak amplitudes were mostly larger, than those of normal group. 3. The group-mean AEP of diabetic group had also similar contour to that of normal group, but the prominent negative peak was N3. Latencies of the components were significantly longer except for that of P5, and peak-to-peak amplitudes were smaller, than those of normal group. 4. The latencies of the diabetic group were significantly shorter, and the peak-to-peak amplitudes were also smaller, than those of non-diabetic group. 5. Quantitative frequency analysis of EEG resulted in significant decrease of α2 power% and increase of β1 power % in non-diabetic group, and significant decrease of β1 power % in diabetic group. 6. Positive correlation was found between δ power % of EEG and the latencies of long-latency components of AEP, and negative correlation between α1, α2, β2 power % and the latencies of middle-long-latency components. Between peak-to-peak amplitudes of AEP, negative correlation was found with δ power %, and positive correlation with β1 power %. 7. Between AEP-latencies, the positive correlation was found with Cr (creatinine) and K (potassium), negative correlation with P (phosphorus). Between AEP-amplitudes, positive correlation was found with BUN and P, and negative correlation with Cr and calcium. These results were considered to be attributed to the more prominent inhibition of GABA-inhibitory system in gray matter in non-diabetics, and to severe disturbances in both white and gray matter in diabetics, reflecting antagonistic influences from pathological condition between non-diabetics (uremia) and diabetic nephropathy

An application of wavelet analysis to the human cerebral evoked potential

Adopting Wavelet analysis for the analysis of the waveform of EP (Evoked Potential), it was intended to confirm possibility of the subjective diagnosis for schizophrenia, epilepsy and healthy subject. 1. Each waveform of EPs (SEP, VEP and AEP) of 100 healthy male subjects (25.4±3.1 y.o.), 100 male schizophrenics (31.6± 10.4 y.o.) and 99 male epileptics (35.9± 13.1 y.o.) were subjected to the Wavelet analysis and the multiresolution analysis. As a result, the difference of Wavelet values among these subject groups were verified significantly. The Wavelet values was defined as the square means of each wavelet coefficients at each scale of multiresolution analysis. 2. The waveform of EPs of each subject were discriminated by use of discriminant method derived from Wavelet Function, in order to judge to which subject group the subject belongs, according to the wavelet values. Analyzing the waveform of EP, between 15~600msec of latency, the highest value of sensitivity, 89%, 87% and 88% was obtained for normal subject, schizophrenics and epileptics, respectively. As the conclusion, the possibility of the subjective diagnosis for schizophrenia, epilepsy, and normal subjects, by Wavelet analysis of EP waveform, were verified possible

The effects of odors of lavender and peppermint on the human AEP (Auditory Evoked Potential) and EEG

The effects of odors (Lavender and Peppermint) on AEP (Auditory Evoked Potential) were studied with 15 healthy male subjects aged 22~39 y. o. (mean : 29.1 ± 4.8 y. o.). EEGs containing AEPs evoked by click stimuli once every 5 seconds were derived from the two derivations (3 ch : Cz→A1 +2, 6 ch : Cz→T5) , and recorded into magnetic tape. Reproducing the tape, AEPs with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. In the experimental session, EEGs containing AEPs were recorded before, during and 15 and 30 minutes after the inhalation of odors of Lavender and Peppermint. Consecutive changes of group mean AEP were studied. Indivisual AEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following results were obtained. 1. Subjective assessment for the intensity and pleasantness of odors was not only so much different between Lavender and Peppermint, but close similar among the subjects. 2. During and after the inhalation of Lavender, latencies of the middle latency AEP including P2 latency, and latencies of long latency components (P6~) significantly or not significantly increased. Peak-to-peak amplitudes including P2-N2 of the middle latecy AEP significantly or not significantly decreased. During and after the inhalation of the odor of Peppermint, latencies of the middle latency AEP including P2 latency decreased but not significant, and peak-to-peak amplitudes including P2-N2 significantly or not significantly increased. Amplitudes of long latency component (P6~) did not change significantly. In conclusion, sedative effect of Lavender and a kind of stimulating effect of Peppermint on the middle latecy component were confirmed by AEP. 3. From the changes of P2, which derived from the brainstem reticular formation, it was said that Lavender inhibited, and Peppermint activated the reticular formation. Increased latencies of the long latency component of AEP during and after Lavender indicated the secondary inhibition of cortex succeeding to inhibition of the brainstem reticular formation. 4. Although the mechanism of olfactory system is not clarified, the odors of Lavender and Peppermint were might be differentiated in olfactory systems below neocortical olfactory area, and act on the reticular formation respectively inhibitorily or excitedly through the medial forebrain bundle. 5. It has been generally said that olfactory stimuli activate the CNS through the brainstem reticular formation, but inhibitory effect of Lavender similar to that of minor traquilizer, besides activating effect of Peppermint was verified for the first time by AEP

The effects of Cigarette Smoking on the human VEP (Visual Evoked Potential) and EEG

The effects of cigarette smoking on the human CNS (Central Nervous System) were studied by VEP (Visual Evoked Potential) with 38 healthy male subjects (20～42 y. o., mean : 18. 6 cig./ day×8. 5 years). All subjects were deprived of smoking from the last night prior to the expriment. In the experimental session the subjects were asked to smoke two cigarettes (nicotine content 2. 7 mg/ cig.) in ten minutes after control recording. EEGs containing VEPs evoked by flash stimuli once every 5 second were recorded into the magnetic tape through the two derivations (2CH : O1→A1+2 and 5CH : O1→Cz) together with EEGs also through four other derivations, simultaneously. Reproducing the tape, VEPs from the two derivations were recorded, with 1000 msec of analysis time, for each recording session ; before, during and 10, 20, 30 min. after cigarette smoking. The EEGs were subjected to the quantitative frequency analysis. VEPs were converted into a series of numbers and subjected to the computer processing and statistical assessment with special reference to the EEG changes. The subjects were divied into the two groups, heavy smoker group and light smoker group (more than/within 15 cig./ day), for further study. The following results were obtained. 1. In the waveforms of group mean VEP recorded from the two drivations, N4 appeared only during cigarette smoking. Latencies of P2～P4 were tended to increase during and after smoking, other latencies tended to decrease during smoking and then increased thereafter. Peak-to-peak amplitudes tended to increase, and then decrease thereafter. In the group mean VEP from 5CH, peak-to-peak amplitudes decreased during and after smoking. Conponent analysis with individual VEPs verified these changes in the group mean VEP significant. These changes in the VEPs were attributed to the early exciting (arousal) effect due to the nicotin attaining to the brain, followed by the inhibiting (sedative) effect due to the short half-life period and tachyphylaxis of nicotin. 2. The correlation coefficients between the number of cigarette smoked in one day and ratio of change of latencies and peak-to-peak amplitudes indicated that the effects of smoking above mentioned appeared more markedly with heavy smokers than with light smokers, indicating more increased susceptibility to nicotin due to cigarette abstinence with the former. 3. Quantitative frequency analysis of EEG indicated arousal effect by the decrease of θ and increase of peak α frequency, and sedative effect by the derease of β1, namely desynchronization. These" arousal sedative effect" corresponded with the VEP changes by cigarette smoking in the present study

Visual Evoked Potential (VEP) and EEG in patients undergoing hemodialysis

The CNS (Central Nervous System) of 20 patients undergoing hemodialysis (dialyzed group, 38~65 y. o.) were studied by VEP (Visual Evoked Potential) comparing with 20 healthy subjects (normal group, 38~66 y. o.). The 20 patients were divided into non-diabetic group of 14 with chronic gromerulonephritis and diabetic group of 6 with diabetic nephropathy. EEGs containing VEPs evoked by flash stimuli once every 5 second were recorded by 100 sweeps with 1024 msec of analysis time, simultaneously through the two derivations (2CH : O1→A1+2 and 5CH : O1→Cz). The EEGs were subjected to the quantitative frequency analysis. These data of VEP were examined between these subject groups, with reference to the EEG and the blood data. The following results were obtained. 1 The waveforms of group mean VEP of normal group, dialyzed group and non-diabetic group had triphasic contour containing dominant components of N3, P6, N8 (2CH) or N3, P5, N8 (5CH), but that of diabetic group severely deteriorated and lost the contour. 2 In dialyzed group and non-diabetic group, latencies of early components (P1-P3) were longer and peak-to-peak amplitudes of late components were larger than those of normal group significantly. 3 Latencies of early components were longer in the ascending order normal group, non-diabetic group and diabetic group, and peak-to-peak amplitudes were smaller in the ascending order non-diabetic group, normal group and diabetic group. 4 Quantitative frequency analysis of EEG indicated that the peak frequency of α waves of dialyzed group and non-diabetic group were smaller, and θ power % of diabetic group were smaller than that of normal group. 5 From the correlation coefficients between the EEG power% and the latencies or the amplitudes of each compenent of VEP, δ power % correlated significantly with the latencies of middle and long latency components in 2CH and those of long latency in 5CH positively. β1 power % correlated significantly with peak-to-peak amplitude of long latency components in 5CH positively. 6 BUN and potassium correlated positively with latencies of early components. BUN correlated positively with peak-to-peak amplitudes. Hemoglobin correlated negatively with latencies. 7 These results indicte that the CNS of diabetic group was disturbed more severely than dialyzed group and non-diabetic group in VEP and EEG, and the inhibitory system (GABA) of optic center cortex related to late components was disturbed first

Visual evoked potential and electroencephalogram of healthy females during the menstrual cycle

Flash visual evoked potential (VEP) and electroencephalogram (EEG) changes during the menstrual cycle were studied using healthy females having regular menstruation, with 21 at the follicular phase (FP) and 23 at the luteal phase (LP). The following results were obtained. (1)The waveforms of Group Mean VEPs of both groups had approximately similar triphasic contours, consisting of 16 components of P 1-N 8 up to 500 msec of latency. (2)Latencies tended to be longer in LP. (3)Interpeak amplitudes tended to be larger in LP, and one VEP interpeak amplitude (P 5-N 7) of long latency component was significantly larger at LP after eliminating the effect of body height by ANCOVA for 2 CH. (4)Quantitative analysis of EEGs between FP and LP resulted in a tendency for increased α, and decreased β power % at LP. Since estrogen increases the VEP amplitude, and decreases the VEP latency and the α activity of EEGs, the large VEP amplitude, the tendency for prolonged VEP latency, and the tendency for increased α power % at LP observed in this study indicate that the VEP amplitude at LP reflects the effect of estrogen, and that the VEP latency and EEGs at LP reflect the effect of progesterone

Somatosensory Evoked Potential (SEP) and EEG of patients undergoing hemodialysis

The SEP (Somatosensory Evoked Potential) and EEG were studied with 19 patients undergoing hemodialysis (dialyzed group, 41~65 y. o.), consisted of non-diabetic group (13 patients with chronic gromerulonephritis) and diabetic group (6 patients with diabetic nephropathy), comparing with those of 20 healthy subjects (normal group, 38~66 y. o.). EEGs containing SEPs evoked by median nerve stimulation were recorded with 1024 msec of analysis time through the two derivations (1CH : C3'→F3' and 4CH : C3'→A1+2). The group-mean SEPs were obtained with each group, and compared with each other, and then the differences of latencies and peak-to-peak amplitudes of the components were tested statistically between the groups. The EEGs were subjected to the quantitative frequency analysis. Correlation coefficients were tested between the latencies, peak-to-peak amplitudes and EEG power %, and between the latencies, peak-to-peak amplitudes and blood data. The following results were obtained. 1. The waveforms of group-mean SEP of normal group and non-diabetic group had hexaphasic contour, consisted of the components Pl~8, N1~8. But, in that of diabetic group the contour deteriorated at around the long latency components. 2. The latencies were longer in the ascending order normal group, non-diabetic group and diabetic group, and peak-to-peak amplitudes were larger in the ascending order diabetic group, normal group and non-diabetic group. 3. In the SEP of non-diabetic group, latencies were increased and amplitudes were decreased. 4. In the SEP of diabetic group, latencies were increased more than those of non-diabetic group, and amplitudes were decreased. 5. Quantitative frequency analysis of EEG, indicated decreased peak frequency of α waves in non-diabetic group, and decreased peak frequency of α waves and increased δ, θ waves in diabetic group, more than those in normal group. 6. The correlation coefficients of EEG power % between SEP-latencies indicated increased latencies due to decreased fast waves and increased slow waves, and those between SEP peak-to-peak amplitudes indicated increased amplitudes due to increased fast waves and decreased slow waves. 7. Between SEP-latencies, negative correlation was found with blood K, Ca, BUN, and positive correlation with dialyzed period (years), and between SEP-amplitudes, negative correlation with creatinin, Ca, hemogrobin, and positive correlation with BUN. These results were attributed to more marked disturbances of GABA-inhibitory system in gray matter together with white matter in non-diabetics, and to severe disturbances of the central nervous system in both of gray and white matter in diabetics

Somatosensory Evoked Potential (SEP) in schizophrenics

The differences between schizophrenics and healthy subjects in Somatosensory Evoked Potential (SEP) were studied with 174 schizophrenics (98 male and 76 female) and 200 healthy subjects (100 male and 100 female). SEPs evoked by electric stimuli to the right median nerve were recorded through the two derivations (monopolar : C3’→A1+2; bipolar: C3’→Cz), averaging 100 responses, with 1024 msec of analysis time. Individual SEPs were subjected to the component analysis, and the following statistically significant results were obtained. 1. In male schizophrenics, the peak latencies of SEP components were significantly longer in short-latency component, P1 (bipolar), compared with healthy subjects, and shorter in middle-latency component, P2. In female schizophrenics, those were longer in middle-latency components, N2, P3, N3 (monopolar), and N1, P3, N3 (bipolar). 2. The inter-peak amplitudes in schizophrenics of both sexes were significantly larger in middle-latency components without any changes in short-latency components. 3. A few components with significant differences in latencies and inter-peak amplitudes between the subjects taking neuroleptics more than 600 mg, in chlorpromazine equivalent values, or not, as well as between medicated and unmedicated subjects, coincided with those also between the schizophrenics and healthy subjects. Theses differences in SEPs confirmed in the present study, regardless of schizophrenic subtypes, suggest the dysfunction in somatosensory information processing in schizophrenics, and SEP abnormalities may serve as possible elctrophysiological indices for cognitive dysfunction in schizophrenics