Development and validation of a simple and rapid UPLC-MS/MS method for loganin and its application in pharmacokinetic and tissue distribution studies

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis Sieb. et Zucc. is a medicinal and edible homolog in traditional Chinese medicine. Loganin, an iridoid glycoside, is one of the main active components of Cornus officinalis Sieb. et Zucc. Loganin has been demonstrated to improve depression-like behavior and may be a potential antidepressant candidate. However, the pharmacokinetic characteristics and tissue distribution of loganin, especially in the brain region, are still unclear.

AIM OF THE STUDY

This study aims to investigate the pharmacokinetic characteristics and tissue distribution after oral administration of loganin in rats.

MATERIALS AND METHODS

A simple, rapid and reproducible UPLC-MS/MS method was developed and validated for the determination of loganin in rat plasma and tissues. The samples were prepared by acetonitrile precipitation with chloramphenicol as internal standard (IS). Loganin was separated by gradient elution on ACQUITY UPLC®BEH C18 (2.1 × 50 mm, 1.7 μm) using multiple reactions monitoring (MRM) mode. Concentration-time data was subjected to pharmacokinetic analysis. The pharmacokinetic parameters of loganin in rat plasma were analyzed by compartment model using DAS 2.0 software.

RESULTS

The established UPLC-MS/MS method was accurate and reliable with a good linearity (R2 > 0.99) in the respective concentration range, satisfying the quantitative requirements. This method was successfully used to study the pharmacokinetics and tissue distribution after oral administration of loganin in rats. The peak time (Tmax) of oral administration was about 40 min, and the half-life (t1/2) was about 50 min, indicating that loganin was quickly absorbed and eliminated in rats. Oral bioavailability was 5.50%. The dose correlation results showed that AUC had a poor correlation with dose, while Cmax had a good correlation with dose. In tissues, loganin (35 mg/kg) was highly distributed in the stomach, small intestine, kidney, liver and lung. When the dose was 70 mg/kg, loganin had significant distribution in the cortex.

CONCLUSION

In this study, a simple and sensitive UPLC-MS/MS method was developed and validated for the determination of loganin in rat plasma and tissues. Loganin was absorbed quickly, eliminated quickly, and had low bioavailability. The distribution of loganin in the cortex was higher than that in the hippocampus. We hope that our results can provide a reference for loganin to become a new antidepressant.

Pharmacological activities and therapeutic potential of galangin, a promising natural flavone, in age-related diseases

BACKGROUND

The extension of average life expectancy and the aggravation of population aging have become the inevitable trend of human development. In an aging society, various problems related to medical care for the elderly have become increasingly prominent. However, most of the age-related diseases have the characteristics of multiple diseases at the same time, prone to complications, and atypical clinical manifestations, which bring great difficulties to its treatment. Galangin (3,5,7-trihydroxyflavone) is a natural active compound extracted from the root of Alpinia officinarum Hance (Zingiberaceae). Recently, many studies have shown that galangin has potential advantages in the treatment of neurodegenerative diseases and cardiovascular and cerebrovascular diseases, which are common in the elderly. In addition, it also showed that galangin had prospective activities in the treatment of tumor, diabetes, liver injury, asthma and arthritis.

PURPOSE

This review aims to systematically summarize and discuss the effects and the underlying mechanism of galangin in the treatment of age-related diseases.

METHODS

We searched PubMed, SciFinder, Web of Science and CNKI literature database resources, combined with the keywords "galangin", "neurodegenerative disease", "tumor", "diabetes", "pharmacological activity", "drug combination", "pharmacokinetics", "drug delivery system" and "safety", and comprehensively reviewed the pharmacological activities and mechanism of galangin in treating age-related diseases.

RESULTS

According to the previous studies on galangin, the anti-neurodegenerative activity, cardiovascular and cerebrovascular protective activity, anti-tumor activity, anti-diabetes activity, anti-arthritis activity, hepatoprotective activity and antiasthmatic activity of galangin were discussed, and the related mechanisms were classified and summarized in detail. In addition, the drug combination, pharmacokinetics, drug delivery system and safety of galangin were furtherly discussed.

CONCLUSIONS

This review will provide reference for galangin in the treatment of age-related diseases. Meanwhile, further experimental research and long-term clinical trials are needed to determine the therapeutic safety and efficacy of galangin.

Simultaneous Determination of Thirteen Iridoid Glycosides in Crude and Processed Fructus Corni from Different Areas by UPLC-MS/MS Method

Fructus Corni (F. Corni) is the dried mature pulp of Cornus officinalis Sieb. et Zucc.(Cornaceae), which is rich in iridoids. In this study, a simple, sensitive and rapid UPLC-MS/MS method was developed for the simultaneous determination of 13 iridoid glycosides of F. Corni from different areas. Specifically, we included five new compounds (cornusdiridoid C, cornusdiridoid E, cornusdiridoid F, 3'',5''-dehydroxycornuside and 2'-O-p-coumaroyl-kingiside) and isomers (2'-O-p-E-coumaroylloganin and 2'-O-p-Z-coumaroylloganin) for the first time in the quality markers of F. Corni. A total of 13 compounds and two pairs of isomers were well isolated and tested within just 14 min. All calibration curves showed good linear regression (r2 ≥ 0.99) within the tested concentration ranges. The limit of detection and limit of quantification were in the range of 0.19-1.90 and 0.38-3.76 ng/mL, respectively. The intra-day and inter-day precision were <3.21% and 12.49%, the RSD values of repeatability did not exceed 6.81% and the average recoveries were 90.95-113.59% for the analytes. All iridoid glycosides stabilized within 12 h (RSD < 10.99%). This method has been successfully applied to the quality evaluation of crude and processed F. Corni from different areas. The determination of characteristic iridoid glycosides and isomers will provide a more reliable and comprehensive method for the evaluation of F. Corni.

Stelleratenoids A-F, macrocyclic daphnane orthoesters with anti-HIV activity from the roots of Stellera chamaejasme L

Six undescribed macrocyclic daphnane orthoesters, stelleratenoids A-F (1-6), were isolated from the roots of Stellera chamaejasme L. Their structures were elucidated by extensive spectroscopic analyses, including HRESIMS and NMR spectra. Compound 1 features an unusual terminal double bond at C-2/C-19 in the 1α-alkyldaphnane lactone skeleton. Compounds 2-4 are unique in the presence of different long chain fatty acyl groups. Compounds 5 and 6 are unique examples of modified macrocyclic daphnane diterpenoids. All the isolates were evaluated for anti-HIV activity in MT-2 cells. Among them, compounds 1, 5 and 6 exhibited highly potent anti-HIV activity with EC₅₀ values of 66.70, 10.62 and 55.10 nM, respectively, possessing high potential to develop new anti-HIV drugs.

Loganin improves chronic unpredictable mild stress-induced depressive-like behaviors and neurochemical dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis Sieb. et Zucc., is a valuable herb commonly used in Chinese medicine clinics. Loganin is a major iridoid glycoside obtained from the traditional Chinese herb Corni Fructus. Loganin, which has been shown to improve depression-like behavior in mice exposed to acute stress, is probably a potential antidepressant candidate.

AIM OF THE STUDY

Loganin was evaluated for its effect on chronic unpredictable mild stress (CUMS) induced depressive-like mice, and its action mechanisms were explored.

MATERIALS AND METHODS

ICR mice were subjected to the CUMS stimulation method to induce depression. The therapeutic effect of loganin on depressive-like behavior was evaluated by a series of behavioral tests such as sucrose preference test (SPT), forced swim test (FST), tail suspension test (TST) and open-field test (OFT). In addition, the serum levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were measured using ELISA. The levels of monoamine neurotransmitters were detected by high performance liquid chromatography-electrochemical detection (HPLC-ECD). The levels of brain-derived neurotrophic factor (BDNF) in the hippocampus were measured using western blot analysis.

RESULTS

The results showed that CUMS induced depressive-like behaviors in mice, as indicated by behavioral tests. Administration of loganin increased the sucrose preference in SPT, as well as decreased the immobility time in FST and TST. Loganin could also improve food intake, and increased crossing times in the OFT. In mechanism, loganin restored the secretion of monoamine neurotransmitters, ACTH and CORT to normal levels. In addition, loganin elevated the expression of BDNF in the hippocampus. In conclusion, loganin exerts antidepressant-like effects in CUMS model mice through modulating monoamine neurotransmitters, ACTH, CORT and BDNF.

CONCLUSION

Loganin effectively ameliorated depressive-like symptoms in CUMS-exposed mice by increasing 5-hydroxytryptamine (5-HT) and dopamine (DA) levels, alleviating hypothalamic-pituitary-adrenal (HPA) axis dysfunction, and increasing BDNF expression. In conclusion, the findings of the current study extensive evidence for the application of loganin in stress-associated disorders, specifically targeting depression.

Hypericin: A natural anthraquinone as promising therapeutic agent

BACKGROUND

Hypericin is a prominent secondary metabolite mainly existing in genus Hypericum. It has become a research focus for a quiet long time owing to its extensively pharmacological activities especially the anti-cancer, anti-bacterial, anti-viral and neuroprotective effects. This review concentrated on summarizing and analyzing the existing studies of hypericin in a comprehensive perspective.

METHODS

The literature with desired information about hypericin published after 2010 was gained from electronic databases including PubMed, SciFinder, Science Direct, Web of Science, China National Knowledge Infrastructure databases and Wan Fang DATA.

RESULTS

According to extensive preclinical and clinical studies conducted on the hypericin, an organized and comprehensive summary of the natural and artificial sources, strategies for improving the bioactivities, pharmacological activities, drug combination of hypericin was presented to explore the future therapeutic potential of this active compound.

CONCLUSIONS

Overall, this review offered a theoretical guidance for the follow-up research of hypericin. However, the pharmacological mechanisms, pharmacokinetics and structure activity relationship of hypericin should be further studied in future research.

New Rosane Diterpenoids and Their Analogs from Euphorbia ebracteolata Hayata

Phytochemical investigation of the roots of Euphorbia ebracteolata Hayata resulted in the isolation of three new rosane diterpenoids, euphebracteolatins C-E (1-3), along with fourteen known analogs (4-17). Their structures were determined on the basis of extensive spectroscopic analysis including HR-ESI-MS, 1D and 2D NMR. Euphebracteolatin C (1) contains a C-1/C-10 double bond and a keto group at C-7, and euphebracteolatins D and E (2-3) possess an aromatic ring-A in their skeleton. The plausible biogenetic pathways of all the isolates were also proposed. Furthermore, compounds 1 and 9 showed selective cytotoxicity against HepG2 cells with IC₅₀ values of 14.29 and 12.33 μM, respectively, and 2-3 displayed moderate cytotoxicity against three human cancer lines, with IC₅₀ values ranging from 23.69 to 39.25 μM.

Hyperforin: A natural lead compound with multiple pharmacological activities

Hypericum perforatum L. (Clusiaceae), commonly known as St. John's wort, has a rich historical background as one of the oldest and most widely studied herbal medicines. Hyperforin is the main antidepressant active ingredient of St. John's wort. In recent years, hyperforin has attached increasing attention due to its multiple pharmacological activities. In this review, the information on hyperforin was systematically summarized. Hyperforin is considered to be a lead compound with diverse pharmacological activities including anti-depression, anti-tumor, anti-dementia, anti-diabetes and others. It can be obtained by extraction and synthesis. Further pharmacological studies and more precise detection methods will help develop a value for hyperforin. In addition, structural modification and pharmaceutical preparation technology will be beneficial to promoting the research progress of hyperforin based innovative drugs. Although these works are full of known and unknown challenges, researchers are still expected to make hyperforin play a greater value.

The NLRP3 inflammasome in depression: Potential mechanisms and therapies

Increasing evidence suggests that the failure of clinical antidepressants may be related with neuroinflammation. The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is an intracellular multiprotein complex, and has been considered as a key contributor to the development of neuroinflammation. Inhibition of NLRP3 inflammasome is an effective method for depression treatment. In this review, we summarized current researches highlighting the role of NLRP3 inflammasome in the pathology of depression. Firstly, we discussed NLRP3 inflammasome activation in patients with depression and animal models. Secondly, we outlined the possible mechanisms driving the activation of NLRP3 inflammasome. Thirdly, we discussed the pathogenetic role of NLRP3 inflammasome in depression. Finally, we overviewed the current and potential antidepressants targeting the NLRP3 inflammasome. Overall, the inhibition of NLRP3 inflammasome activation may be a potential therapeutic strategy for inflammation-related depression.

Jolkinolide B: A comprehensive review of its physicochemical properties, analytical methods, synthesis and pharmacological activity

Jolkinolide B is a typical ent-abietane-type diterpenoid, which is first found in Euphorbia jolkini. It is one of the most important active components in many toxic Euphorbia plants. In recent years, jolkinolide B has garnered increasing attention due to its high potent and multiple pharmacological activities. In order to better understand the research status of jolkinolide B, relevant information about jolkinolide B was collected from scientific databases (SciFinder Scholar, PubMed, ACS website, Elsevier, Web of Science, Google Scholar, Science Direct, and CNKI). There are few studies on chemical synthesis and biosynthesis of jolkinolide B. In addition, researchers on the activities of jolkinolide B are mostly concentrated at the cellular level, and there is a lack of research on the mechanism. In this review, the possible applications of jolkinolide B were systematically illustrated for the first time, from plant sources, physicochemical properties, analytical methods, synthesis and pharmacological activities. Jolkinolide B exhibits extensive pharmacological properties, including anticancer, anti-inflammatory, anti-osteoporosis, and anti-tuberculosis activities. Pharmacological activities of jolkinolide B were mainly focused on anticancer and anti-inflammatory activities, and the mechanism of action may be related with inhibition of JAK/STAT pathway, NF-κB pathway and PI3K/Akt/mTOR pathway. In addition, the extraction methods and analytical methods discussed in this review, will facilitate the development of novel herbal products for better healthcare solutions.

Sigma-1 receptor: A potential target for the development of antidepressants

Though a great many of studies on the development of antidepressants for the therapy of major depression disorder (MDD) and the development of antidepressants have been carried out, there still lacks an efficient approach in clinical practice. The involvement of Sigma-1 receptor in the pathological process of MDD has been verified. In this review, recent research focusing on the role of Sigma-1 receptor in the etiology of MDD were summarized. Preclinical studies and clinical trials have found that stress induce the variation of Sigma-1 receptor in the blood, brain and heart. Dysfunction and absence of Sigma-1 receptor result in depressive-like behaviors in rodent animals. Agonists of Sigma-1 receptor show not only antidepressant-like activities but also therapeutical effects in complications of depression. The mechanisms underlying antidepressant-like effects of Sigma-1 receptor may include suppressing neuroinflammation, regulating neurotransmitters, ameliorating brain-derived neurotrophic factor and N-Methyl-D-Aspartate receptor, and alleviating the endoplasmic reticulum stress and mitochondria damage during stress. Therefore, Sigma-1 receptor represents a potential target for antidepressants development.

Diverse gallotannins with α-glucosidase and α-amylase inhibitory activity from the roots of Euphorbia fischeriana steud

A phytochemical investigation of the roots of Euphorbia fischeriana Steud. led to the isolation of eleven undescribed gallotannins, fishertannins A-K, together with four known analogues. Their structures were elucidated by the comprehensive spectroscopic data including UV, IR, HR-ESI-MS, and NMR, while the absolute configurations of the sugar moiety were determined by the acid hydrolysis and HPLC analyses. Fishertannin A possessed an unusual skeleton comprised of acetophenone, galloyl group, arabinofuranosyl and glucopyranosyl moieties. Fishertannin B, fishertannin H, fishertannin K, 1,2,3-tri-O-galloyl-β-D-glucopyranose, 3,4,6-tri-O-galloyl-D-glucopyranose, and 1,6-di-O-galloyl-β-D-glucopyranose displayed the potent α-glucosidase inhibitory activities with the IC₅₀ values of 15.48-177.13 μM. Examination of the structure-activity relationships (SAR) demonstrated that the galloyl and glucopyranosyl moieties played a key role in the inhibitory activity for both α-glucosidase and α-amylase inhibitory activity. Among all isolates, 1,2,3-tri-O-galloyl-β-D-glucopyranose showed the most potent and highly specific inhibitory activity against α-glucosidase with an IC₅₀ value of 15.48 ± 0.60 μM. The kinetic analysis of 1,2,3-tri-O-galloyl-β-D-glucopyranose disclosed the mixed inhibition type on α-glucosidase, and the molecular docking visualized the stable binding with the catalytic pocket of α-glucosidase (pdb 3A4A). These findings indicated the excellent antidiabetic potential of the gallotannins from E. fischeriana, while 1,2,3-tri-O-galloyl-β-D-glucopyranose could be developed as a promising candidate for the treatment of T2DM with fewer side effects.

Cornuside ameliorates cognitive impairments in scopolamine induced AD mice: Involvement of neurotransmitter and oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis Sieb. et Zucc., traditional Chinese medicine, has been widely used in the treatment of dementia. Cornel iridoid glycosides of Cornus officinalis is therapeutic to Alzheimer's disease (AD), while its pharmacodynamic material basis is not clear. Cornuside, an iridoid glycoside extracted from of Cornus officinalis Sieb. et Zucc, might be a potential anti-AD candidate.

AIM OF THE STUDY

Cornuside was evaluated for its effect on scopolamine induced AD mice, and its action mechanisms were explored.

MATERIALS AND METHODS

ICR mice were administered with 1 mg/kg scopolamine intraperitoneally to induce amnesia. The therapeutic effect of cornuside of cognitive function was evaluated via series of behavioral tests, including Morris water maze test, step-through test and step-down test. In addition, specific enzyme reaction tests were used to detect the content of acetylcholine (ACh) and malondialdehyde (MDA), as well as the activities of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), choline acetyltransferase (ChAT), superoxide dismutase (SOD), catalase (CAT), monoamine oxidase (MAO) in the brain. The levels of monoamine neurotransmitters were detected by high performance liquid chromatography-electrochemical detection (HPLC-ECD).

RESULTS

Cornuside ameliorated the spatial memory impairment in Morris water maze test and cognitive disruption in step-through and step-down test. Furthermore, cornuside improved the level of ACh by reducing the activities of AChE and BuChE, and increasing the activity of ChAT in hippocampus. Cornuside also increased the levels of monoamine neurotransmitters by inhibiting MAO activity in hippocampus and cortex. In addition, cornuside attenuated MDA by enhancing the activities of SOD and CAT in hippocampus and cortex.

CONCLUSION

Cornuside improved cognitive dysfunction induced by scopolamine in behavioral tests. The mechanisms of cornuside were further investigated from the aspects of neurotransmitters and oxidative stress. Cornuside could inhibit oxidative stress and neurotransmitter hydrolases, increase ACh and monoamine neurotransmitters, which finally contributed to its therapeutic effect on scopolamine induced amnesia.

The untapped potential of spermidine alkaloids: Sources, structures, bioactivities and syntheses

Spermidine alkaloids are a kind of natural products possessing an aliphatic triamine structure with three or four methylene groups between two N-atoms. Spermidine alkaloids exist in plants, microorganisms, and marine organisms, which usually form amide structures with cinnamic acid or fatty acid derivatives. Their unique structures showed a wide range of biological activities such as neuroprotective, anti-aging, anti-cancer, antioxidant, anti-inflammatory, and antimicrobial. In order to better understand the research status of spermidine alkaloids and promote their applications in human health, this paper systematically reviewed the biological sources, structures, pharmacological actions, and synthetic processes of spermidine alkaloids over the past two decades. This will help to open up new pharmacological investigation fields and better drug design based on these spermidine alkaloids.

Phytochemistry, synthesis, analytical methods, pharmacological activity, and pharmacokinetics of loganin: A comprehensive review

Iridoid glycosides (IGs) are found in many medicinal and edible plants, such as Gardenia jasminoides, Cistanche tubulosa, Eucommia ulmoides, Rehmanniae Radix, Lonicera japonica, and Cornus officinalis. Loganin, an IG, is one of the main active ingredient of Cornus officinalis Sieb. et Zucc., which approved as a medicinal and edible plant in China. Loganin has been widely concerned due to its extensive pharmacological effects, including anti-diabetic, antiinflammatory, neuroprotective, and anti-tumor activities, etc. Studies have shown that these underlying mechanisms include anti-oxidation, antiinflammation and anti-apoptosis by regulating a variety of signaling pathways, such as STAT3/NF-κB, JAK/STAT3, TLR4/NF-κB, PI3K/Akt, MCP-1/CCR2, and RAGE/Nox4/p65 NF-κB signaling pathways. In order to better understand the research status of loganin and promote its application in human health, this paper systematically summarized the phytochemistry, analysis methods, synthesis, pharmacological properties and related mechanisms, and pharmacokinetics based on the research in the past decades.

Jolkinolide B alleviates renal fibrosis via anti-inflammation and inhibition of epithelial-mesenchymal transition in unilateral ureteral obstruction mice

Renal fibrosis is a critical pathological process lead to a progressive loss of renal function. Jolkinolide B (JB) is a natural compound with anti-inflammatory activity from Euphorbia fischeriana Steud. The study evaluated the effect of JB on renal fibrosis in mice with unilateral ureteral obstruction (UUO). The results showed that JB could decrease renal fibrotic area, reduce phosphorylation of NF-κB p65 and the release of TNF-α, IL-6 and IL-1β, restore the expression of vementin, α-SMA and E-cadherin, as well as TGF-β1 and p-smad2/3. In conclusion, JB might reduce renal fibrosis by inhibiting inflammation induced by NF-κB pathway and EMT mediated by TGF-β1/Smad pathway.

Identifying the mechanism underlying antidepressant-like effects of loganin by network pharmacology in combination with experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Loganin, an iridoid glycoside, is one of the quality control indexes of Cornus officinalis Sieb. et Zucc. Increasing evidence emphasize the important role of inflammation in the pathology of depression, which links depression with other chronic diseases. Loganin prevents inflammatory response in multiple diseases and reverses depressive-like behaviors. However, the mechanisms underlying antidepressant-like effects of loganin for the treatment of inflammation-associated depression are not utterly understood.

AIM OF THE STUDY

The present study was designed to predict the potential targets of loganin against inflammation-associated depression using a network pharmacology approach.

MATERIALS AND METHODS

Pharmmapper and Uniport were used to predict loganin-related targets. Targets of inflammation were identified through GeneCards databases and Online Mendelian Inheritance in Man (OMIM). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to identify the potential mechanism. Finally, qRT-PCR and ELISA were used to confirm the role of loganin on these targets.

RESULTS

There were 15 nodes in the loganin-inflammation-depression intersection targets network. In the network, the degree value of CTNNB1 was above 3. Among top ten pathways identified by KEGG analysis, Th1/Th2 cell differentiation and IL-17 signaling pathways were related with both inflammation and depression. As indicated by qRT-PCR results, loganin increased CTNNB1 mRNA level. Moreover, loganin elevated M2 markers of microglia but decreased M1 markers of microglia against lipopolysaccharide (LPS), indicated by qRT-PCR results and ELISA results.

CONCLUSION

CTNNB1 was the main target of loganin. Loganin alleviated LPS-induced inflammation through inhibiting M1 polarization of microglia. Our results provide a better understanding of loganin-induced antidepressant-like effects for the treatment of inflammation-associated depression.

Loganin ameliorates depression-like behaviors of mice via modulation of serotoninergic system

RATIONALE

Depression is a serious neuropsychiatric disorder, which is characterized by sustaining mood disorders. Loganin, a major iridoid glycoside from Corni fructus, has a variety of pharmacological activities, including neuroprotective effect and hypnotic effect. However, little is known about the effects of loganin on stress-induced depression.

OBJECTIVE

To investigate the effects of loganin on behavioral despair of mice, and whether serotonin (5-HT) and/or noradrenaline (NE) are involved in this process.

METHODS

We tested the effectiveness of loganin using tail suspension test (TST). The possible mechanism was explored using reserpine-induced ptosis and hypothermia, and 5-HTP-induced head-twitch response in mice. The changes of 5-HT and NE in the prefrontal cortex, hippocampus, and striatum were measured through high-performance liquid chromatography (HPLC) analysis. Then, we identified the effects of depleting 5-HT and NE by PCPA (p-chlorophenylalanine) and DSP-4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride) pretreatment, respectively.

RESULTS

Loganin (12.5/50 mg/kg) induced antidepressant-like effects in mice submitted to TST. Loganin (12.5/50 mg/kg) ameliorated the reserpine-induced hypothermia and ptosis, as well as increased 5-HTP-induced head-twitch responses in mice. Loganin (50 mg/kg) significantly increased the levels of 5-HT in the prefrontal cortex, hippocampus, and striatum. Furthermore, only PCPA treatment could eliminate loganin-induced antidepressant-like effects in TST.

CONCLUSION

Loganin exerts antidepressant-like effect in the TST depending on 5-HT levels in the central nervous system, which provide a potential agent for depression therapy.

Secoiridoid dimers and their biogenetic precursors from the fruits of Cornus officinalis with potential therapeutic effects on type 2 diabetes

Cornusdiridoid A-F (1-6), six unusual cornuside-morroniside secoiridoid dimers, and their possible new biogenetic precursor, 3″,5″-dehydroxycornuside (7), together with four known secoiridoids (8-11), were obtained from the fruits of Cornus officinalis. Their structures were elucidated on the basis of various spectroscopic and chemical methods. A plausible biosynthetic pathway of compounds 1-11 was proposed. The α-glucosidase inhibitory, antioxidant and anti-inflammatory activities of these isolates were evaluated. Some of them emerged out as potent antidiabetic, anti-inflammatory and free radical scavenging agents. Molecular docking was also carried out for antidiabetic target α-glucosidase to investigate the possible binding modes of the most potent α-glucosidase inhibitor, vincosamide (9). These results revealed that the secoiridoids from C. officinalis fruits may be served as new potential antidiabetic agents to prevent and treat type 2 diabetes.

[Overview of characteristics and prevention and control status of foreigners living with HIV in China]

HIV infection among foreign personnel is one of the nonnegligible issues to control the epidemic of HIV/AIDS in China. It is necessary for HIV infection among foreign personnel to be taken effective measures in China. This paper consists of information about epidemic characteristics among foreign personnel with HIV in China, including influence on the overall infection, geographical distribution, and prevention status, referencing more effective AIDS knowledge and health education and behavior intervention.

Existing knowledge on Euphorbia fischeriana Steud. (Euphorbiaceae): Traditional uses, clinical applications, phytochemistry, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia fischeriana Steud. (Euphorbiaceae) is a perennial herb distributed in grassland, hill slopes or gravel hillside, with average altitude of 100-600 m. The whole grass of E. fischeriana is toxic with roots used as folk medicine to treat Zhushui, dyspepsia, abdominal distension, abdominal pain, cough, as well as external applications such as cure of scabies and tuberculosis of lymph nodes.

AIM OF THE REVIEW

This systematic review aims to provide a detailed and in-depth summary about the reported advances in traditional uses, clinical applications, phytochemistry, pharmacology and toxicity of E. fischeriana, so as to offer fresh ideas and broader vision and insights for subsequent studies.

MATERIALS AND METHODS

Various scientific data bases such as CNKI, Elsevier, Google Scholar, Pubmed, Science Direct, SciFinder Scholar and Web of Science were searched to collect information about E. fischeriana. Other relevant literatures were searched in 'Flora of China Editorial Committee', ancient books, Ph.D and Masters' Dissertation to get more data of E. fischeriana.

RESULTS

A total of 241 chemical constituents have been identified from the roots of E. fischeriana, including diterpenoids, triterpenoids, meroterpenoids, acetophenones, flavonoids, coumarins, steroids, phenolic acids, tannins, etc. Various pharmacological activities have been demonstrated, especially anti-tumor, antibacterial, anti-inflammatory, antiviral and anti-leukemia activities. Moreover, different investigations about clinical uses and toxicology of E. fischeriana indicated that attention should be paid to its usage and dosage.

CONCLUSION

The researches of E. fischeriana are excellent, but gap still remains. As a poisonous traditional Chinese medicine, there are not enough studies on the toxicity of E. fischeriana. In addition, scholars' research on the pharmacological mechanism of E. fischeriana focuses more on the anti-tumor activity, which can be broadened in the future. Presumably, chemical constituents and biological activities of diterpenoids and trace meroterpenoids in E. fischeriana deserve further research in-depth in the future, in order to provide low toxicity and high efficiency lead compounds. Meanwhile, further studies on other medicinal aspects may lay a foundation for the comprehensive development and utilization of E. fischeriana.

Euphorbia ebracteolata Hayata (Euphorbiaceae): A systematic review of its traditional uses, botany, phytochemistry, pharmacology, toxicology, and quality control

Euphorbia ebracteolata Hayata, as a traditional medicine, is widely distributed in China, Korea and Japan. In China, the dried root of this plant is named 'langdu'. It is traditionally used to treat oedema, skin ulcers, abdominal distension, cough, asthma, tuberculosis swelling and other diseases. Previous studies have found that the chemical constituents of E. ebracteolata are mainly concentrated in terpenoids, acetophenones, and flavonoids. Both extracts and pure compounds from E. ebracteolata were found to possess many pharmacological activities, such as anticancer, anti-inflammatory, antiviral, and antimicrobial effects. In addition, it was reported that E. ebracteolata shows toxicity. To provide inspiration for further in-depth studies on this plant, this review will provide a timely and systematic summary of E. ebracteolata in traditional uses, phytochemistry, pharmacology toxicology, and quality control.

Fischdiabietane A, an Antitumoral Diterpenoid Dimer Featuring an Unprecedented Carbon Skeleton from Euphorbia fischeriana

Fischdiabietane A (1), a novel asymmetric diterpenoid dimer with a unique nonacyclic 6/6/6/5/7/6/6/6/6 ring system possessing unprecedented 2-oxaspiro[4.5]decane-1-one and 2-oxabicyclo[3.2.2]nonane frameworks in D/E/F rings, was isolated from the roots of Euphorbia fischeriana. Its structure was determined by spectroscopic techniques, electronic circular dichroism calculations, and X-ray diffraction experiments. Notably, 1 is the first abietane-type [4 + 2] Diels-Alder dimer identified from nature. The IC₅₀ of 1 against T47D cells was about sixfold higher than that of cisplatin (the positive control). Furthermore, 1 induced apoptosis in T47D cells through the activation of caspase-3 and the degradation of poly(ADP-ribose) polymerase.

Ethnopharmacology, phytochemistry, pharmacology, clinical applications and toxicology of the genus Stellera Linn.: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Stellera Linn. consists of species of perennial herbs and shrubs, and is mainly distributed in the temperate regions of east Asia to west Asia. There are 10∼12 species in the world, two species in China: Stellera chamaejasme Linn. and Stellera formosana Hayata ex Li. As recorded, the roots of Stellera species are used to dissipate phlegm and relieve pain. The roots and the barks can be used for papermaking.

AIM OF THIS REVIEW

This review aims to summarize the ethnopharmacological uses, chemical constituents, pharmacological activities, clinical applications and toxicology of the genus Stellera to better understand their therapeutic potential in the future.

MATERIALS AND METHODS

The relevant information of the genus Stellera was collected from scientific databases (Pubmed, ACS website, SciFinder Scholar, Elsevier, Google Scholar, Web of Science and CNKI). Information was also gathered from 'Flora Republicae Popularis Sinicae (〈〈〉〉)', folk records, conference papers on ethnopharmacology, Ph.D. and Masters' Dissertation.

RESULTS

Stellera plants have been studied as traditional folk medicines all around the world. The chemical constituents of Stellera species mainly comprise terpenoids, flavonoids, coumarins, lignans, and so on. Extracts and compounds of Stellera species exhibit extensive pharmacological activities, such as anti-tumor, anti-viral, anti-convulsive, anti-epileptic, anti-bacterial and anti-insect activities, etc. Clinical applications have suggested that the genus Stellera has the effects in treating several skin diseases and cancers, however, the results should be further verification. The genus Stellera plants are toxic and should be used reasonable.

CONCLUSION

This paper reviewed the ethnopharmacological uses, chemical constituents, pharmacology, clinical applications and toxicology of the genus Stellera. The genus Stellera has broad application prospects. However, further in-depth studies are needed to determine the medical uses of the genus and its chemical constituents, pharmacological activities, clinical applications and toxicology.

Triterpene saponins from the seeds of Erythrophleum fordii and their cytotoxic activities

Erythrosides A-G, seven undescribed oleanane-type triterpenoid saponins, were isolated from the seeds of Erythrophleum fordii. Their structures with absolute configurations were determined by extensive spectroscopic analysis including one-dimensional [1D] and two-dimensional [2D] nuclear magnetic resonance [NMR], high-resolution electrospray ionization mass spectroscopy [HR-ESI-MS] analysis, and chemical methods. Erythrosides A-G featured a diverse oligosaccharide chain containing 4-6 pentoses or hexoses at C-3 and a monoterpenic acid or a (E)-cinnamic acid unit at the C-21 position. Of particular interest, erythrosides A-C, E and F contained a rare alpha xylose in their sugar chains. The bioassay results indicated that erythrosides A-C showed moderate cytotoxic activities against human lung cancer cell line PC9 with IC₅₀ values of 13.14, 16.67 and 17.59 μM, respectively (the positive control, Taxol, IC₅₀ = 0.60 nM).

[Analysis on influencing factors on HIV testing behaviors in some foreigners in Guangzhou]

Objective: To analyze the influencing factors of HIV testing behavior among foreigners in Guangzhou, and provide a reference for promoting HIV testing and intervention services in foreigners. Methods: A cross-sectional survey was conducted from November 2019 to January 2020 among 230 eligible foreigners selected in Guangzhou through convenient sampling method in the form of one-to-one questionnaire interview, HIV testing behaviors and related influencing factors were described and analyzed with χ(2) test and multivariate logistic regression model. Results: A total of 230 foreigners were included in the study, in whom 156 were males (67.8%), 217 were from Africa (94.3%), 138 (60.0%) were with education level of university and above, 169 (73.5%) were in business, 47 (20.4%) were students, 132 (57.4%) had cumulative residence >12 months in Guangzhou and 113 (49.1%) had health examination in China in the past 6 months. In these foreigners, the rate of AIDS-related knowledge awareness was 76.0%, the proportion of condom use in the last sex was 39.6%(89/225) and 47.8%(110/230) received HIV tests in the past 3 months. Multivariate logistic regression analysis showed, the influencing factors of HIV testing behavior in the past 3 months included cumulative residence ≤12 months (compared with cumulative residence >12 months, OR=3.12, 95%CI: 1.49-6.56), health examination in China in the past 6 months (compared to those who had not, OR=2.53, 95%CI: 1.17-5.48), awareness of HIV testing and consulting service in Guangzhou (compared with those who had no awareness, OR=3.65, 95%CI: 1.71-7.78). Conclusions: Some foreigners in Guangzhou had relatively low rates of HIV testing and condom use. Those who pay attention to their own health status and know well about HIV testing and consulting services are more likely to receive HIV testing, foreigners in Guangzhou should be encouraged to receive HIV testing. Their self-testing awareness should be improved.

Connexins in oligodendrocytes and astrocytes: Possible factors for demyelination in multiple sclerosis

Increasing evidences support that glial connexins are involved in the demyelination pathology of multiple sclerosis (MS), a chronic inflammatory demyelinating disorder. Here, we review the data from patients with MS and animal models of MS that implicate connexins in demyelination. Connexins expressed in oligodendrocytes and astrocytes show diverse changes at the different phases of MS. Loss of oligodendrocyte or astrocyte connexins contributes to demyelination and exaggerates the pathology of MS. Channel-dependent and -independent connexins are involved in the pathology of demyelination, which is related with myelin integrity, metabolic homeostasis, the brain-blood barrier, the immune cell infiltration, and the inflammatory response. A comprehensive understanding of connexin function in demyelination may provide new therapeutic targets for MS.

Undescribed morroniside-like secoiridoid diglycosides with α-glucosidase inhibitory activity from Corni Fructus

Corni Fructus, also known as the fruit of Cornus officinalis Sieb. et Zucc., has long been used as a traditional Chinese medicine and is widely consumed as a nutritional food in the form of function drink and wine. Recently, Corni Fructus has attracted considerable interest because of its anti-diabetic effects. A systematic phytochemical investigation of Corni Fructus was performed to find anti-diabetic components, which led to the isolation of 10 unreported iridoid glycosides, cornusdiglycosides A-J (1-8, 9a/9b and 10a/10b). Their chemical structures were determined through spectroscopic analysis (ultraviolet [UV], infrared [IR], high-resolution electrospray ionisation mass spectroscopy [HRESIMS], one-dimensional [1D] and two-dimensional [2D] nuclear magnetic resonance [NMR]). Such morroniside-type diglycosides were first reported from natural sources, and all isolates were evaluated for α-glucosidase inhibitory activity. The results showed that all compounds (1-10) exhibited α-glucosidase (from Saccharomyces cerevisiae) inhibitory activities with IC₅₀ values ranging from 78.9 ± 4.09 to 162.2 ± 9.17 μM, whereas acarbose, the positive control, displayed α-glucosidase inhibitory activity with IC₅₀ value of 118.9 ± 7.89 μM.

Cornusglucosides A and B, Two New Iridoid Glucosides from the Fruit of Cornus officinalis

Phytochemical study on the fruit of Cornus officinalis Sieb. et Zucc. yielded two new iridoid glucosides, named cornusglucoside A (1) and cornusglucoside B (2). The structures of 1 and 2 were elucidated via comprehensive NMR and HR-ESI-MS data analysis. Additionally, their inhibitory effects on IL-6-induced STAT3 activation were assessed.

[A new phenylpropanoid glycoside from fruit of Cornus officinalis]

To investigate the chemical compounds from the ripe fruit of Cornus officinalis, a new phenylpropanoid glycoside 1-O-(6'-O-p-hydroxybenzoyl-β-D-glucopyranosyl)-p-phenylpropanol, named cornuphenylpropanoid A (1), were separated and purified by D101 macroporous resin, silica gel and ODS column chromatography. Its structure was extensively determined on basis of ¹H-NMR, ¹³C-NMR, DEPT, HSQC, HMBC and HR-ESI-MS spectroscopic data.

Loganin Exerts Sedative and Hypnotic Effects via Modulation of the Serotonergic System and GABAergic Neurons

Corni fructus, the fruit of Cornus officinalis Sieb. et Zucc., has been used as a tonic for the kidney in China for thousands of years. Loganin is one of the major constituents derived from Corni fructus. In this study, we revealed the sedative and hypnotic activity of loganin and investigated its mechanisms for the first time. Pentobarbital-induced sleep test and insomnia mice models [induced by caffeine and p-chlorophenylalanine (PCPA)] were used for the assessment of sedative and hypnotic effects of loganin. It was found that loganin (20–50 mg/kg) exerted sedative effect in normal mice. Loganin exhibited hypnotic effect by increasing sleep onset and sleep duration in pentobarbital-treated mice, recovering PCPA-induced insomnia and exerting synergistic hypnosis effect with 5-HTP. In addition, electroencephalograph (EEG) and electromyography (EMG) recordings of rats showed that loganin (35 mg/kg) prolonged the ratio of non-rapid eye movement (NREM) sleep and shortened wakefulness significantly, further immunohistochemistry showed that loganin (35 mg/kg) increased c-Fos expression in GABAergic neurons of rats in the ventrolateral preoptic nucleus (VLPO). The levels of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and its metabolite were measured in the hippocampus, prefrontal cortex and striatum of mice, 1 h after loganin (35 mg/kg) treatment. 5-HT, 5-HIAA/5-HT, DA, and DOPAC were decreased significantly in the prefrontal cortex. In conclusion, these results indicated that loganin produced beneficial sedative and hypnotic activity, which might be mainly mediated by modification of the serotonergic system and GABAergic neurons.

Fischernolides A–D, four novel diterpene-based meroterpenoid scaffolds with antitumor activities from Euphorbia fischeriana

Fischernolides A–D (1–4), representing the rare 28-carbon meroterpenoid skeleton of abietane and an acylphloroglucinol conjugate, bearing an α-furanone or α-pyrone ring, were isolated and identified from the roots of Euphorbia fischeriana.

Fischeriana A, a meroterpenoid with an unusual 6/6/5/5/5/6/6 heptacyclic carbon skeleton from the roots of Euphorbia fischeriana

Fischeriana A (1), a new meroterpenoid with a rare carbon skeleton, was isolated from the roots of Euphorbia fischeriana.

Unusual cadinane-type sesquiterpene glycosides with α-glucosidase inhibitory activities from the fruit of Cornus officinalis Sieb. et Zuuc

Five novel and rare cadinane-type sesquiterpene glycosides, cornucadinoside A-E (1-5) were isolated from water extract of the fruit of Cornus officinalis Sieb. et Zuuc.. The new chemical structures, together with their absolute configurations, were elucidated on the basis of extensive spectroscopic analysis, including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Their structures, which possess a naphthalene skeleton, are the first report on the occurrence of cadinane sesquiterpene glycosides in Cornus. Additionally, all the compounds exhibited marked α-glucosidase inhibitory activity except for 3in vitro.

[A new lignan from rhizome of Stellera chamaejasme]

To investigate the chemical compounds from the rhizome of Stellera chamaejasme, nine lignans, including stellerachamin A (1), 8-hydroxypluviatolide (2), wikstromol (3), pinoresinol (4), matairesinol (5), dextrobursehernin (6), hinokinin(7), (-)-glaberide I (8) and （-） medioresinol (9) were isolated by various chromatographic methods. Their structures were extensively determined on basis of MS and NMR spectroscopic data analysis. Among them, compound 1 was a new lignan, and compounds 2 and 7 were isolated from Thymelaeaceae for the first time.

Cornusides A-O, Bioactive Iridoid Glucoside Dimers from the Fruit of Cornus officinalis

Fifteen new and rare iridoid glucoside dimers, cornusides A-O (1-15), and 10 known iridoid glucosides (16-25) were isolated from the fruit of Cornus officinalis. These new chemical structures were established through spectroscopic analysis (UV, IR, HRESIMS, 1D and 2D NMR). Compounds 1-25 were tested for their inhibitory activities by measuring IL-6-induced STAT3 promoter activity in HepG2 cells, and 3, 12, 17, 22, and 23 showed inhibitory effects, with IC₅₀ values of 11.9, 12.2, 14.0, 7.0, and 6.9 μM, respectively.

Four new iridoid glucosides containing the furan ring from the fruit of Cornus officinalis

Four new and rare iridoid glucosides, cornusfuroside A-D (1-4), containing the furan ring were identified from water extract of the fruit of Cornus officinalis. These new chemical structures were determined through extensive spectroscopic analysis, including 1D and 2D NMR, IR, HRESIMS, experimental and calculated electronic circular dichroism (ECD). Notably, this study is the first report on the isolation of four iridoid glucoside structures with acetal functions in the sugar moiety. The neuroprotective effects of these compounds were also evaluated in vitro.

Ent-abietane diterpenoids and their probable biogenetic precursors from the roots of Euphorbia fischeriana

Five new ent-abietane diterpenoid fischeriabietanes A–E (1–5), along with nine known analogues (6–14), were isolated from the roots of Euphorbia fischeriana and their biosynthetic relationships were discussed.

Renoprotective effect of berberine on type 2 diabetic nephropathy in rats

Inflammation, fibrosis, and lipid disorder are essential promoters in the pathogenesis of diabetic kidney injury in diabetes mellitus type 2. Berberine (BBR) has been reported to have beneficial effects on diabetic nephropathy, but its action mechanism is still unclear. The present study was designed to elucidate the therapeutic mechanism of BBR in a type 2 diabetic nephropathy rat model induced by a high-fat diet and low-dose streptozotocin injection. The diabetic rats were treated with or without BBR by gavage for 20 weeks and examined by serology, 24-h albuminuria, histology, immunohistochemistry, and molecular analyses. Results showed that treatment with BBR significantly reduced serum levels of blood glucose and lipids, inhibited urinary excretion of albumin, and attenuated renal histological injuries in diabetic rats. Berberine treatment also inhibited renal inflammation, which was associated with inactivation of nuclear factor kappa-light-chain-enhancer of activated B-cell signalling. As a result, the upregulation of pro-inflammatory cytokines (interleukin-1β, tumour necrosis factor-α) and chemokine (monocyte chemotactic protein-1) was blocked. In addition, BBR treatment also inactivated transforming growth factor-β/Smad3 signalling and suppressed renal fibrosis, including expression of fibronectin, collagen I, and collagen IV. The present study reveals that BBR is a therapeutic agent for attenuating type 2 diabetic nephropathy by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cell-driven renal inflammation and transforming growth factor-β/Smad3 signalling pathway.

Three new cyathane diterpenoids from the medicinal fungus Cyathus africanus

Three new cyathane diterpenoids, cyathin W (1), cyathin V (2), and cyathin T (3), were isolated from the solid culture of Cyathus africanus. The structures and configurations of these new compounds were elucidated on the basis of comprehensive spectroscopic analysis including 1D NMR, 2D NMR (HSQC, HMBC, NOESY), and HR-ESI-MS experiments. Compounds 1 and 3 showed moderate inhibition against nitric oxide production in lipopolysaccaride-activated macrophages with IC50 value of 80.07 and 88.87 μM, respectively. In cytotoxicity assay, compound 1 showed weak cytotoxicity against K562 cell line with IC50 value of 12.1 μM.

[Flavonoids from Humulus lupulus]

Nine compounds were isolated and purified by column chromatographic techniques including macroporous resin, silica gel, ODS, Sephadex LH-20, and preparative reversed-phase HPLC. Their structures were elucidated as taxifolin (1), naringenin (2), chalconaringenin (3), acacetin (4), quercetin 3-O-beta-D-galactopyranoside (5), 6-prenylnaringenin (6) xanthohumol (7), desmethylxanthohumol (8), xanthohumol B (9) on the basis of MS and NMR spectroscopic data analysis. Compounds 1-5 were isolated from Humulus lupulus for the first time.

[Determination of theacrine in rat plasma by RP-HPLC]

OBJECTIVE

To establish a method for the determination of theacrine in rat plasma after ig. administration of theacrine.

METHOD

Blood sample was taken timely from the eyes canthus of rats. Plasma was isolated and the protein was precipitated by ethyl acetate. Then the plasma concentration of theacrine was determined with RP-HPLC. Caffeine was used as the internal standard. The chromatographic conditions were as follows: Phenomenex Luna C18 (4.6 mm x 250 mm, 5 microm) at 25 degrees C, a mixture of methanol-water (25: 75) as the mobile phase, at the flow rate of 1.0 mL x min(-1) and the detection wavelength of 290 nm.

RESULT

The linear range of theacrine was 0.5-100 mg x L(-1) (R2 = 0.998 9). The lower limit of quantification was 0.5 mg x L(-1). The intra-day RSD was 1.49% 4.40% and inter-day RSD was 0.80% -10.27%. The average extraction recoveries of theacrine were 90.3% -95.8% at concentrations of 0.5, 5.0, 50 mg x L(-1). The main pharmacokinetic parameters after ig. administration of theacrine at concentration of 30 mg x kg(-1) were as follow: C(max) (35.45 +/- 30 2.68) mg x L(-1), t(max) (0.51 +/- 0.13) h, t1/2 (3.13 +/- 1.37) h, AUC(0-infinity) (2.65.39 +/- 94.71) mg x L(-1) x h.

CONCLUSION

The method has been confirmed to be simple, stable, reproducible and with high specificity, and can be used for the pharmacokinetic study of theacrine in rats.

A highly porous NiO/polyaniline composite film prepared by combining chemical bath deposition and electro-polymerization and its electrochromic performance

A highly porous NiO/polyaniline (PANI) composite film was prepared on ITO glass by combining the chemical bath deposition and electro-polymerization methods, successively. The porous NiO film acts as a template for the preferential growth of PANI along NiO flakes, and the NiO/PANI composite film has an intercrossing net-like morphology. The electrochromic performance of the NiO/PANI composite film was investigated in 1 M LiClO(4)+1 mM HClO(4)/propylene carbonate (PC) by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The NiO/PANI thin film exhibits a noticeable electrochromism with reversible color changes from transparent yellow to purple and presents quite good transmittance modulation with a variation of transmittance up to 56% at 550 nm. The porous NiO/polyaniline (PANI) composite film also shows good reaction kinetics with fast switching speed, and the response time for oxidation and reduction is 90 and 110 ms, respectively.

Sphingolipids with neuritogenic activity from Euphorbia sororia

Two groups of sphingolipids 1 and 2 were isolated from the aerial parts of Euphorbia sororia. On the basis of spectroscopic data, chemical methods and GC-MS analysis, the structures of 1 and 2 were characterized as 1-O-beta-D-glucopyranosyl-(2S,3S,4R,8Z)-2-[(2'R)-2'-hydroxydocosanoyl approximately hexacosanoyl, octacosanoyl amino]-1,3,4-octadecanetriol-8-ene and (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxyeicosanoyl approximately hexacosanoyl amino]-1,3,4-octadecanetriol-8-ene, respectively. Both of them exhibited marked neuritogenic activity on the rat pheochromocytoma PC12 cell line.

[Studies on chemical constituents of Euphorbia sororia]

OBJECTIVE

To study the chemical constituents of the aerial parts of Euphorbia sororia.

METHOD

Isolation and purification were carried out by silica gel and Sephadex LH -20 column chromatographies. Compounds were identified by physicochemical properties and spectral analysis.

RESULT

Ten compounds were isolated from the plant . Their structures were identified as kaempferol (1), scopoletin (2) , kaempferol 3-O-glucopyranoside (3) , quercetin (4) , vanillic acid (5) , E-p-hydroxycinnamic acid (6) , protocatechuic acid (7), 6, 7-dihydroxycoumarin (8), beta-sitosterol (9), and daucosterol (10) , respectively.

CONCLUSION

All the above compounds were isolated from the plant for the first time.

Photoassisted Charge Behavior of Hydrogen Storage Alloy-TiO2/Pt Electrodes

The photoassisted charge behavior of hydrogen storage alloy modified with TiO2/Pt nanocomposites (HSA-TiO2/Pt electrode) was investigated. The HSA-TiO2/Pt electrode can be photocharged under current. The mechanism of photoassisted behavior of the HSA-TiO2/Pt electrode was explained through the results of cyclic voltammogram and impedance measurements of the HSA-TiO2/Pt electrode. Upon illumination, the photogenerated electrons can charge the electrode, but the photogenerated holes may oxidize the hydrogen storage alloy to form a layer of metal oxide. Because the current could keep the electrode active, the H atoms produced by photogenerated electrons diffused to the hydrogen storage alloy and a metal hydride formed. The electrode delivered a higher discharge capacity due to the assistance of photocharge.