Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 235
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Bioorg Chem ; 148: 107428, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38733749

ABSTRACT

Five pairs of new merosesquiterpenoid enantiomers, named dauresorcinols A-E (1-5), were isolated from the leaves of Rhododendron dauricum. Their structures were elucidated by comprehensive spectroscopic data analysis, quantum chemical calculations, Rh2(OCOCF3)4-induced ECD, and single-crystal X-ray diffraction analysis. Dauresorcinols A (1) and B (2) possess two new merosesquiterpene skeletons bearing an unprecedented 2,6,7,10,14-pentamethyl-11-oxatetracyclo[8.8.0.02,7.012,17]octadecane and a caged 15-isohexyl-1,5,15-trimethyl-2,10-dioxatetracyclo[7.4.1.111,14.03,8]pentadecane motif, respectively. Plausible biosynthetic pathways of 1-5 are proposed involving key oxa-electrocyclization and Wagner-Meerwein rearrangement reactions. (+)/(-)-1 and 3-5 showed potent α-glucosidase inhibitory activity, 3 to 22 times stronger than acarbose, an antidiabetic drug targeting α-glucosidase. Docking results provide a basis to design and develop merosesquiterpenoids as potent α-glycosidase inhibitors.


Subject(s)
Glycoside Hydrolase Inhibitors , Rhododendron , Rhododendron/chemistry , Stereoisomerism , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/isolation & purification , Molecular Structure , Structure-Activity Relationship , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacology , Sesquiterpenes/isolation & purification , alpha-Glucosidases/metabolism , Molecular Docking Simulation , Humans , Dose-Response Relationship, Drug , Plant Leaves/chemistry , Crystallography, X-Ray , Models, Molecular
2.
Bioorg Chem ; 142: 106928, 2024 01.
Article in English | MEDLINE | ID: mdl-37922768

ABSTRACT

A systematical investigation on the chemical constituents of the flowers of Rhododendron molle (Ericaceae) led to the isolation and characterization of thirty-eight highly functionalized grayanane diterpenoids (1-38), including twelve novel analogues molleblossomins A-L (1-12). Their structures were elucidated by comprehensive methods, including 1D and 2D NMR analysis, calculated ECD, 13C NMR calculations with DP4+ probability analysis, and single crystal X-ray diffraction. Molleblossomins A (1), B (2), and E (5) are the first representatives of 2ß,3ß:9ß,10ß-diepoxygrayanane, 2,3-epoxygrayan-9(11)-ene, and 5,9-epoxygrayan-1(10),2(3)-diene diterpenoids, respectively. Molleblossomins G (7) and H (8) represent the first examples of 1,3-dioxolane-grayanane conjugates furnished with the acetaldehyde and 4-hydroxylbenzylidene acetal moieties, respectively. All grayanane diterpenoids 1-38 were screened for their analgesic activities in the acetic acid-induced writhing model, and all of them exhibited significant analgesic activities. Diterpenoids 6, 13, 14, 17, 20, and 25 showed more potent analgesic effects than morphine at a lower dose of 0.2 mg/kg, with the inhibition rates of 51.4%, 68.2%, 94.1%, 66.9%, 97.7%, and 60.0%, respectively. More importantly, even at the lowest dose of 0.04 mg/kg, rhodomollein X (14), rhodojaponin VI (20), and rhodojaponin VII (22) still significantly reduced the number of writhes in the acetic acid-induced pain model with the percentages of 61.7%, 85.8%, and 64.6%, respectively. The structure-activity relationship was summarized and might provide some hints to design novel analgesics based on the functionalized grayanane diterpenoids.


Subject(s)
Diterpenes , Rhododendron , Rhododendron/chemistry , Molecular Structure , Flowers/chemistry , Analgesics/pharmacology , Analgesics/therapeutic use , Analgesics/chemistry , Diterpenes/pharmacology , Diterpenes/therapeutic use , Diterpenes/chemistry , Acetic Acid/analysis
3.
Sensors (Basel) ; 24(9)2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38732933

ABSTRACT

This paper investigates a method for precise mapping of human arm movements using sEMG signals. A multi-channel approach captures the sEMG signals, which, combined with the accurately calculated joint angles from an Inertial Measurement Unit, allows for action recognition and mapping through deep learning algorithms. Firstly, signal acquisition and processing were carried out, which involved acquiring data from various movements (hand gestures, single-degree-of-freedom joint movements, and continuous joint actions) and sensor placement. Then, interference signals were filtered out through filters, and the signals were preprocessed using normalization and moving averages to obtain sEMG signals with obvious features. Additionally, this paper constructs a hybrid network model, combining Convolutional Neural Networks and Artificial Neural Networks, and employs a multi-feature fusion algorithm to enhance the accuracy of gesture recognition. Furthermore, a nonlinear fitting between sEMG signals and joint angles was established based on a backpropagation neural network, incorporating momentum term and adaptive learning rate adjustments. Finally, based on the gesture recognition and joint angle prediction model, prosthetic arm control experiments were conducted, achieving highly accurate arm movement prediction and execution. This paper not only validates the potential application of sEMG signals in the precise control of robotic arms but also lays a solid foundation for the development of more intuitive and responsive prostheses and assistive devices.


Subject(s)
Algorithms , Arm , Electromyography , Movement , Neural Networks, Computer , Signal Processing, Computer-Assisted , Humans , Electromyography/methods , Arm/physiology , Movement/physiology , Gestures , Male , Adult
4.
Angew Chem Int Ed Engl ; : e202407303, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38837854

ABSTRACT

The Li-CO2 batteries utilizing greenhouse gas CO2 possess advantages of high energy density and environmental friendliness. However, these batteries following Li2CO3-product route typically exhibit low work voltage (<2.5 V) and energy efficiency. Herein, we have demonstrated for the first time that cobalt phthalocyanine (CoPc) as homogeneous catalyst can elevate the work plateau towards 2.98 V, which is higher than its theoretical discharge voltage without changing the Li2CO3-product route. This unprecedented discharge voltage is illustrated by mass spectrum and electrochemical analyses that CoPc has powerful adsorption capability with CO2 (-7.484 kJ/mol) and forms discharge intermediate of C33H16CoN8O2. Besides high discharge capacity of 18724 mAh/g and robust cyclability over 1600 hours (1000 mAh/g cut-off) at a current density of 100 mA/g , the batteries show high temperature adaptability (-30~80 °C). Our work is paving a promising avenue for the progress of high-efficiency Li-CO2 batteries.

5.
Brain Cogn ; 171: 106061, 2023 10.
Article in English | MEDLINE | ID: mdl-37451074

ABSTRACT

Altruism is defined as the performance of "costly acts that confer economic benefits on other individuals", which is one of the major puzzles in the behavioural sciences today. Altruistic behaviour not only facilitates interpersonal adaptation and harmony but also enhances social welfare and social responsibility. The right temporo-parietal junction (rTPJ) has been proposed as playing a key role in guiding human altruistic behaviour, but its precise functional contribution to altruistic behaviour in situations of advantageous and disadvantageous inequity remains unclear. The purpose of this study was to modulate the activation of the rTPJ through transcranial direct current stimulation (tDCS) in order to clarify the causal role of the rTPJ in altruistic behaviour in situations of advantageous and disadvantageous inequity. A total of 106 participants were randomly assigned to one of three stimulation conditions: anodal tDCS stimulation on the rTPJ; sham tDCS stimulation on the rTPJ and anodal tDCS stimulation on the primary visual cortex (VC)as the control group, and. After 20 min of stimulation, participants undertook a modified dictator game that measured altruistic behaviour. Mixed-effect logistic regressions were applied to statistical analyses in this study. The results indicated that anodal tDCS over the rTPJ increased participants' altruistic tendency by increasing their tendency to choose altruistic options in trials with higher cost, as well as their tendency to behave altruistically in situations of advantageous but not disadvantageous inequity. These results suggested that increased neural activity of the rTPJ leads to different impacts on altruism in these two different inequity situations.


Subject(s)
Parietal Lobe , Transcranial Direct Current Stimulation , Humans , Parietal Lobe/physiology , Temporal Lobe/physiology , Altruism , Transcranial Direct Current Stimulation/methods
6.
Bioorg Chem ; 132: 106374, 2023 03.
Article in English | MEDLINE | ID: mdl-36682149

ABSTRACT

Twenty-eight grayanane diterpenoids (1-28) including 13 new ones, named daublossomins A-M (1-13), and two new natural products, 3-O-acetylgrayanotoxin II (14) and 10-epi-grayanotoxin III (15), were isolated from the flowers of Rhododendron dauricum L. (Ericaceae). Their structures were elucidated by means of comprehensive spectroscopic methods and quantum chemical calculations (13C NMR-DP4+ analysis and calculated ECD), and the absolute configurations of ten grayanane diterpenoids 1, 4, 5, 7, 8, 22, 23, 25, 27, and 28 were determined by X-ray crystallographic analysis. Daublossomin A (1) represents the first example of an 11,16-epoxygrayan-6-one diterpenoid. Daublossomins B (2) and C (3) are the first examples of 9ß,10ß-epoxygrayanane diterpenoids, and daublossomin I (9) is the second conjugated grayan-1(5),6(7),9(10)-triene diterpenoid. Compounds 1-11 and 13-27 were evaluated for their analgesic activities in the HOAc-induced writhing test in mice, and 1-8, 10, 11, 13, 15, 17, 18, 22-24, and 26 exhibited significant analgesic effects at a dose of 5.0 mg/kg (inhibition rates > 50%). Among them, daublossomins A (1) and F (6) still showed potent analgesic activity even at a lower dose of 0.2 mg/kg with the inhibition rates of 54.4% and 55.2%, respectively. Grayanotoxin III (20) showed more potent analgesic activities than the positive control, morphine, at a dose of 0.04 mg/kg. A preliminary structure-activity relationship for the analgesic grayanane diterpenoids was discussed, providing some useful clues to design and develop structurally novel potent analgesics.


Subject(s)
Diterpenes , Rhododendron , Mice , Animals , Rhododendron/chemistry , Molecular Structure , Plant Leaves/chemistry , Analgesics/pharmacology , Analgesics/chemistry , Flowers/chemistry , Diterpenes/pharmacology , Diterpenes/chemistry
7.
Proc Natl Acad Sci U S A ; 117(2): 950-958, 2020 01 14.
Article in English | MEDLINE | ID: mdl-31888986

ABSTRACT

Engaging in altruistic behaviors is costly, but it contributes to the health and well-being of the performer of such behaviors. The present research offers a take on how this paradox can be understood. Across 2 pilot studies and 3 experiments, we showed a pain-relieving effect of performing altruistic behaviors. Acting altruistically relieved not only acutely induced physical pain among healthy adults but also chronic pain among cancer patients. Using functional MRI, we found that after individuals performed altruistic actions brain activity in the dorsal anterior cingulate cortex and bilateral insula in response to a painful shock was significantly reduced. This reduced pain-induced activation in the right insula was mediated by the neural activity in the ventral medial prefrontal cortex (VMPFC), while the activation of the VMPFC was positively correlated with the performer's experienced meaningfulness from his or her altruistic behavior. Our findings suggest that incurring personal costs to help others may buffer the performers from unpleasant conditions.


Subject(s)
Altruism , Brain/physiology , Pain/physiopathology , Adult , Aged , Brain Mapping , Cerebral Cortex/physiology , Female , Gyrus Cinguli/physiology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Nervous System Physiological Phenomena , Pilot Projects , Prefrontal Cortex/physiology , Young Adult
8.
Sensors (Basel) ; 23(15)2023 Jul 28.
Article in English | MEDLINE | ID: mdl-37571537

ABSTRACT

Corals play a crucial role as the primary habitat-building organisms within reef ecosystems, forming expansive structures that extend over vast distances, akin to the way tall buildings define a city's skyline. However, coral reefs are vulnerable to damage and destruction due to their inherent fragility and exposure to various threats, including the impacts of climate change. Similar to successful city management, the utilization of advanced underwater videography, photogrammetric computer vision, and machine learning can facilitate precise 3D modeling and the semantic mapping of coral reefs, aiding in their careful management and conservation to ensure their survival. This study focuses on generating detailed 3D mesh models, digital surface models, and orthomosaics of coral habitats by utilizing underwater coral images and control points. Furthermore, an innovative multi-modal deep neural network is designed to perform the pixel-wise semantic segmentation of orthomosaics, enabling the projection of resulting semantic maps onto a 3D space. Notably, this study achieves a significant milestone by accomplishing semantic fine-grained 3D modeling and rugosity evaluation of coral reefs with millimeter-level accuracy, providing a potent means to understand coral reef variations under climate change with high spatial and temporal resolution.


Subject(s)
Anthozoa , Coral Reefs , Animals , Ecosystem , Semantics , Climate Change , Machine Learning
9.
Brain Cogn ; 164: 105927, 2022 12.
Article in English | MEDLINE | ID: mdl-36343582

ABSTRACT

Human beings have a strong preference for the fair distribution of resources in situations of both advantageous and disadvantageous inequity. Neuroimaging studies have shown that the process of advantageous and disadvantageous inequity aversion involves distinct brain regions. However, little is known about the causal roles of the dorsal medial prefrontal cortex (dmPFC) in these two types of inequity aversion. To clarify the roles of the dmPFC in both types of inequity aversion, 70 subjects were recruited and randomly assigned to two anodal transcranial direct current stimulation (tDCS) groups: tDCS over the dmPFC and tDCS over the primary visual cortex. Participants then completed a dictator game, which was used to measure the aversion to inequity. This study found that tDCS over the dmPFC decreased the aversion to disadvantageous inequity, but not that to advantageous inequity, and the treatment effect was modulated by equity cost. These results show that the dmPFC plays different roles in these two types of inequity aversion.


Subject(s)
Transcranial Direct Current Stimulation , Humans , Transcranial Direct Current Stimulation/methods , Prefrontal Cortex/physiology , Brain , Neuroimaging , Affect
10.
Sensors (Basel) ; 21(7)2021 Apr 02.
Article in English | MEDLINE | ID: mdl-33918171

ABSTRACT

As important sensors in smart sensing systems, smartwatches are becoming more and more popular. Authentication can help protect the security and privacy of users. In addition to the classic authentication methods, behavioral factors can be used as robust measures for this purpose. This study proposes a lightweight authentication method for smartwatches based on edge computing, which identifies users by their tapping rhythms. Based on the DBSCAN clustering algorithm, a new classification method called One-Class DBSCAN is presented. It first seeks core objects and then leverages them to perform user authentication. We conducted extensive experiments on 6110 real data samples collected from more than 600 users. The results show that our method achieved the lowest Equal Error Rate (EER) of only 0.92%, which was lower than those of other state-of-the-art methods. In addition, a statistical method for detecting the security level of a tapping rhythm is proposed. It can prevent users from setting a simple tapping rhythm password, and thus improve the security of smartwatches.

11.
Bioorg Chem ; 96: 103598, 2020 03.
Article in English | MEDLINE | ID: mdl-32007721

ABSTRACT

Sixteen lanostane-type triterpene glycosides including eight new ones, named lyonicarposides A-H (1-8), were isolated from the flowers of Lyonia ovalifolia var. hebecarpa (Franch. ex F.B. Forbes & Hemsl.) Chun (Ericaceae). The chemical structures of the new compounds were elucidated by the comprehensive spectroscopic techniques and chemical methods. The Mo2(OAc)4-induced electronic circular dichroism method was used to determine the absolute configurations of C-24 in lyonicarposides A (1), C (3), and E (5). This is the first phytochemical study on the flowers of L. ovalifolia var. hebecarpa. All the isolates were evaluated for their antiproliferative activities against SMMC-7721, HL-60, SW480, MCF-7, and A-549 cell lines. Lyonicarposides A (1) and B (2) showed moderate antiproliferative activities against five cancer cell lines with IC50 values ranging from 12.39 to 28.71 µM. Lyonicarposides C (3) and G (7) and lyonifoloside M (12) selectively inhibited the proliferation of HL-60 and MCF-7 cell lines with IC50 values ranging from 13.03 to 17.71 µM. Interestingly, lyonifoloside L (13) selectively inhibited the proliferation of MCF-7 cell line with an IC50 value of 16.27 µM. Their structure-activity-relationships were discussed.


Subject(s)
Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Ericaceae/chemistry , Triterpenes/chemistry , Triterpenes/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Flowers/chemistry , Glycosides/chemistry , Glycosides/pharmacology , Humans , Neoplasms/drug therapy , Structure-Activity Relationship
12.
J Sep Sci ; 43(21): 4058-4066, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32861220

ABSTRACT

A new extraction method, microwave absorption medium-assisted extraction coupled with reversed-phase dispersive liquid-liquid microextraction, was developed for the determination of triazine herbicides in corn and soybean samples. Triazine herbicides were extracted with hexane and then directly enriched into the ionic liquid phase. The purification of sample and concentration of target analytes were performed simultaneously. The method combines the advantages of nonpolar solvent dynamic microwave extraction and reversed-phase dispersive liquid-liquid microextraction, which could greatly simplify the operation and reduce the whole pretreatment time. The Box-Behnken design was used to the optimization of experimental factors involved in the dynamic microwave-assisted extraction. In the present study, good linearity in the range of 5.00-500.00 µg/kg was obtained. The limits of detection and quantification varying from 1.3 to 4.2 and 4.1 to 13.9 µg/kg were achieved, respectively. The intra- and interday precisions were between 2.7 and 6.9%. The present method was applied to the analysis of corn and soybean samples, and the recoveries of analytes ranged from 80.7 to 106.9% with the relative standard deviations of 2.1-7.8%. The present method shows the potentials of practical applications in the treatment of the complex fatty solid samples.


Subject(s)
Glycine max/chemistry , Herbicides/analysis , Liquid Phase Microextraction , Microwaves , Triazines/analysis , Zea mays/chemistry
13.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(3): 334-337, 2020 Mar 28.
Article in English, Zh | MEDLINE | ID: mdl-32386027

ABSTRACT

The current outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, China, has posed significant threats to international health. By Feb. 20, 2020, 74 576 cases have been confirmed and over 2 118 deaths have reported in the Chinese mainland. Chinese administrations have carried out immediate and prompt measures to stop the spread of the virus. Wuhan city has been shut down since Jan. 23, and more than 30 thousand medical workers have been recruited to Hubei province. Two temporary hospitals were constructed to treat severe pneumonia patients, and 15 mobile cabin hospitals were built to treat mild pneumonia cases. Significant improvement regarding the pathogenesis, epidemiology, and diagnosis and therapy for the COVID-19 has been achieved to stop the spread of the epidemics.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Pneumonia, Viral/epidemiology , COVID-19 , China , Epidemics , Humans , Pandemics , SARS-CoV-2
14.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(5): 591-597, 2020 May 28.
Article in English, Zh | MEDLINE | ID: mdl-32879112

ABSTRACT

The emergence of novel coronavirus pneumonia which was named as coronavirus disease 2019 (COVID-19) by the World Health Organization, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a serious threat to public health. Notably, COVID-19 has rapidly spread around the world and large amount of people have been infected. There is imminent need to investigate the pathogenesis of SARS-CoV-2 and develop effective therapeutic strategies to contain the epidemic. The spike (S) protein of SARS-CoV-2 mediates viral entry into target cells, with S1 subunit binding to a cellular receptor and S2 subunit fusing viral and host membranes. Angiotensin-converting enzyme 2 (ACE2), previously known as a cell receptor of severe acute respiratory syndrome coronavirus (SARS-CoV), is putatively responsible for mediating COVID-19. In this review, we detail our current understanding of the interaction between S protein and ACE2 in the process of virus infection and the potential pathogenesis of SARS-CoV-2, which has critical implications for exploring the potential therapeutic strategies for COVID-19.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections , Pandemics , Peptidyl-Dipeptidase A , Pneumonia, Viral , Spike Glycoprotein, Coronavirus , Angiotensin-Converting Enzyme 2 , COVID-19 , Humans , SARS-CoV-2 , Virus Internalization
15.
Hum Brain Mapp ; 40(3): 967-975, 2019 02 15.
Article in English | MEDLINE | ID: mdl-30311322

ABSTRACT

Human decision-making can be irrational, as in the case of the gambler's fallacy (GF). Converging evidence from behavioral and functional neuroimaging studies has suggested that a hyperactive cognitive system and a hypo-active affective system contribute to the false world model that generates the GF. However, the neuroanatomical basis underlying the GF remains unclear. The current study addressed this issue by collecting high-resolution magnetic resonance anatomical images from a large sample of 350 healthy Chinese adults. Univariate voxel-based morphometry (VBM) analysis suggested that the gray matter volume (GMV) in the anterior cingulate cortex (ACC) and medial temporal lobe (MTL) (two regions of the cognitive system) showed negative correlations with the degree of GF, while the GMV in the striatum and orbitofrontal cortex (OFC; two regions of the affective system) showed positive correlations. Further multivariate VBM analysis showed that the GMV in these regions could potentially predict the degree of GF. Moreover, a mediation analysis suggested that the GMV in MTL, ACC, and OFC mediated the relationships between the cognitive abilities or affective decision-making performance and the GF. Results of our study help us to understand the potential neural bases of the cognitive system's constructive role and the affective system's destructive role in decision making.


Subject(s)
Brain/physiology , Decision Making/physiology , Emotions/physiology , Female , Gambling/physiopathology , Humans , Magnetic Resonance Imaging , Male , Young Adult
16.
Anal Bioanal Chem ; 411(25): 6677-6686, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31372701

ABSTRACT

The antioxidant capacity of 22 kinds of fruits was measured by the developed electron spin resonance (ESR) method based on Cu2+ sensor. Cu2+ is reduced to Cu+ by the antioxidants in the fruits, and the remaining Cu2+ was determined by ESR and UV-Vis spectroscopy. Cu2+ can give an ESR signal whereas Cu+ cannot, and the loss of the ESR signal was used to quantify the antioxidant capacity of various fruits. The results were shown as vitamin C equivalent antioxidant capacity (VCEAC). The VCEAC values obtained by ESR and UV-Vis methods ranged from 24.23 to 688.61 mg/100 g and from 24.12 to 677.79 mg/100 g, respectively. Cupric ion reducing antioxidant capacity (CUPRAC) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) methods were employed for comparison. Based on Pearson's correlation test, the results obtained by CUPRAC and DPPH methods were both significantly correlated with these obtained by the present method, which indicated that the novel method was reliable. Total phenolic content for all kinds of fruits was measured with the Folin-Ciocalteu reagent, and VCEAC values obtained by the ESR method were significantly correlated with total phenolic contents. Graphical abstract.


Subject(s)
Antioxidants/analysis , Electron Spin Resonance Spectroscopy/methods , Fruit/chemistry , Phenols/analysis , Ascorbic Acid/analysis , Cations, Divalent/chemistry , Copper/chemistry , Limit of Detection , Oxidation-Reduction
17.
J Nat Prod ; 82(12): 3330-3339, 2019 12 27.
Article in English | MEDLINE | ID: mdl-31809052

ABSTRACT

Thirteen new grayanane diterpenoids (1-13) and 15 known analogues (14-28) were isolated from a leaf extract of Pieris japonica. Their structures were determined by spectrometric and spectroscopic methods, including HRESIMS, NMR, IR, and UV. The absolute configurations of 1, 3, 7-9, and 16 were defined by single-crystal X-ray diffraction analysis. 17-Hydroxygrayanotoxin XIX (1) represents the first example of a 17-hydroxygrayan-15(16)-ene diterpenoid. Diterpenoids 1-28 were evaluated for their antinociceptive activities, and 4, 9, 13, 21, and 26-28 displayed significant antinociceptive activities at a dose of 5.0 mg/kg (ip) in the HOAc-induced writhing test in mice. 17-Hydroxygrayanotoxin XIX (1) exhibited potent antinociceptive effects with writhe inhibition rates of 56.3% and 64.8% at doses of 0.04 and 0.2 mg/kg, respectively, which were almost equivalent to the positive control, morphine. Rhodomollein X (26) and rhodojaponin VI (27) showed more potent antinociceptive effects than morphine at doses of 0.04 and 0.2 mg/kg. A preliminary structure-activity relationship for the antinociceptive effects of diterpenoids 1-28 is discussed.


Subject(s)
Analgesics/pharmacology , Diterpenes/pharmacology , Ericaceae/chemistry , Plant Leaves/chemistry , Analgesics/chemistry , Analgesics/isolation & purification , Animals , Crystallography, X-Ray , Diterpenes/chemistry , Diterpenes/isolation & purification , Mice , Molecular Structure , Spectrum Analysis/methods , Structure-Activity Relationship
18.
J Nat Prod ; 82(7): 1849-1860, 2019 07 26.
Article in English | MEDLINE | ID: mdl-31246460

ABSTRACT

Twenty-four grayanane diterpenoids (1-24) including 12 new ones (1-12) were isolated from Rhododendron auriculatum. The structures of the new grayanane diterpenoids (1-12) were defined via extensive spectroscopic data analysis. The absolute configurations of compounds 2-4, 10-12, 14, and 16 were established by single-crystal X-ray diffraction analysis, and electronic circular dichroism data were used to define the absolute configurations of auriculatols D (8) and E (9). Auriculatol A (1) is the first example of a 5,20-epoxygrayanane diterpenoid bearing a 7-oxabicyclo[4.2.1]nonane motif and a trans/cis/cis/cis-fused 5/5/7/6/5 pentacyclic ring system. Auriculatol B (2) is the first example of a 3α,5α-dihydroxy-1-ßH-grayanane diterpenoid. 19-Hydroxy-3-epi-auriculatol B (6) and auriculatol C (7) represent the first examples of 19-hydroxygrayanane and grayan-5(6)-ene diterpenoids, respectively. Diterpenoids 1-24 showed analgesic activities in the writhing test induced by HOAc, and 2, 6, 10, 13, 19, and 24 at a dose of 5.0 mg/kg exhibited significant analgesic effects (inhibition rates >50%). Grayanane diterpenoids grayanotoxins I (19) and IV (24) at doses of 0.2 and 0.04 mg/kg showed more potent analgesic activities than morphine.


Subject(s)
Analgesics/pharmacology , Diterpenes/isolation & purification , Diterpenes/pharmacology , Plant Leaves/chemistry , Rhododendron/chemistry , Carbon-13 Magnetic Resonance Spectroscopy , Circular Dichroism , Crystallography, X-Ray , Diterpenes/chemistry , Dose-Response Relationship, Drug , Molecular Structure , Proton Magnetic Resonance Spectroscopy
19.
BMC Musculoskelet Disord ; 20(1): 438, 2019 Sep 29.
Article in English | MEDLINE | ID: mdl-31564252

ABSTRACT

BACKGROUND: The aim of this study was to find out whether the shear wave elastography (SWE) findings of patients with unilateral lumbar disc herniation (LDH) were related to clinical characteristics. METHODS: For this purpose, the study group included patients (N = 20; 13 male, 7 female) with complaints of unilateral sciatica, with foraminal stenosis caused by one level of LDH (L4-L5 or L5-S1). An gender-and age-matched control group (N = 27; 16 male, 11 female) was included. All the patients were examined on both the axial and longitudinal planes bilaterally at the same level using a convex array probe (1- 6 MHz, Supersonic Imagine, Aix en Provence, France). RESULTS: The sciatic nerve stiffness measured on longitudinal planes of the affected side was significantly higher than unaffected side (p < 0.001) and the control group (P < 0.05). Furthermore, the symptom duration of unilateral LDH is positively correlated with the stiffness the sciatic nerve (r = 0.52, p = 0.019). CONCLUSION: According to these findings, ultrasound imaging can be considered as a useful tool to detect changes in the sciatic nerve due to disc herniation. This technique will have a promising prospect for many patients with unilateral LDH in monitoring stiffness during rehabilitation and before or after surgery.


Subject(s)
Elasticity Imaging Techniques/methods , Intervertebral Disc Displacement/diagnostic imaging , Sciatic Nerve/diagnostic imaging , Sciatica/diagnostic imaging , Adult , Case-Control Studies , Female , Humans , Intervertebral Disc/diagnostic imaging , Intervertebral Disc Displacement/complications , Intervertebral Disc Displacement/therapy , Lumbar Vertebrae/diagnostic imaging , Magnetic Resonance Imaging , Male , Middle Aged , Sciatica/etiology , Sciatica/therapy , Treatment Outcome
20.
Ecotoxicol Environ Saf ; 174: 129-136, 2019 Jun 15.
Article in English | MEDLINE | ID: mdl-30825735

ABSTRACT

Zeolite has traditionally been used to remediate wastewater and soil. The present study shows a new method for natural zeolite (NZ) modification with wood vinegar (WV). The optimal conditions for NZ modification with WV were determined, and the adsorption capacities towards lead (Pb), cadmium (Cd) and arsenic (As), antimicrobial activities against Escherichia coli, heavy metal(loid) fraction and characterizations of selected modified zeolites (MZs) were also investigated. The results indicate that 50-fold dilution of WV, 5 g of NZ dosage, 105 °C of drying temperature, 4 h and 95 °C of water bath are preferred for NZ modification with WV. The WV+NaOH-MZ exhibited the best performance in heavy metal removal and the most powerful antimicrobial activity among all the zeolites. The sequence of WV+NaOH-MZ for the maximum single metal(loid) adsorption capacities was Pb (48.67 mg/g) >Cd (23.67 mg/g) > As (0.024 mg/g). The WV+NaOH and WV modifications also can increase the stabilities of heavy metals in the MZs. The residual fractions of single Pb and Cd in WV+NaOH-MZ and WV-MZ were 50%, 55%, 34% and 30%, respectively. The pore size of WV+NaOH-MZ (11.73 nm) was bigger than that of NZ or WV-MZ. Additionally, the proportion of clinoptilolite in WV+NaOH-MZ was also higher than other zeolites. The surfaces of WV+alkali-MZs were rougher than that of NZ. Considering the low cost and environmental risk of WV, this work provides some useful information for management of agricultural and industrial residues, environment and food safety.


Subject(s)
Acetic Acid/chemistry , Arsenic/analysis , Escherichia coli/metabolism , Metals, Heavy/analysis , Methanol/chemistry , Water Pollutants, Chemical/analysis , Zeolites/chemistry , Adsorption , Arsenic/metabolism , Cadmium/analysis , Cadmium/metabolism , Disinfection/methods , Lead/analysis , Lead/metabolism , Metals, Heavy/metabolism , Soil/chemistry , Wastewater/chemistry , Water Pollutants, Chemical/metabolism , Zeolites/analysis
SELECTION OF CITATIONS
SEARCH DETAIL