This study is to establish the fingerprint for Phyllanthus emblica and their tannin parts from different habitats by HPLC for its quality control. The determination was carried out on a Diamonsil C18 (4.6 mm x 250 mm, 5 microm) column, with methanol-0.2% glacial acetic acid as mobile phase with gradient elution at a flow rate of 1 mL x min(-1). The temperature was maintained at 30 degrees C and the detected wavelength is 260 nm, Thirteen chromatographic peaks were extracted as the common peaks of the fingerprint of P. emblica, and eleven as the common peaks of P. emblica tannin parts, and five peaks were identified by comparing with referent samples. The fingerprints of 8 samples were compared and classified by similarity evaluation, cluster analysis and principal component analysis (PCA). The similarity degrees of eight P. emblica were between 0.763 and 0.993, while tannin parts were between 0.903 and 0.991. All the samples of P. emblica and their tannin parts were classified into 3 categories. The method was so highly reproducible, simple and reliable that it could provide basis for quality control and evaluation of P. emblica from different habitats.
Objective: To identify the common Tibetan herb Chuan-Bu.; Method: Local herbalists were visited to observe which plants were being used as Chuan-Bu. Samples of the indigenous plants were collected at the same time. Leaf materials were collected from field surveys. Total genomic DNA was extracted from silica gel-dried leaf samples. The PCR products were purified and directly sequenced.; Result: As the origin of Chuan-Bu in Tibet autonomous region was authenticated, two species were determined, i. e. Euphorbia stracheyiand E. wallichii. Also, based on our earlier research, the origin of Chuan-Bu in Gansu province, is from E. kansuensis. The sequences of ITS1 for E. stracheyi and E. wallichii were 261 bp in size, and 221 bp in ITS2, respectively. The size of the 5.8S coding region was 164 bp for all species examined in the genus. Especially, there was a heterozygous locus in ITS1 (C/G; position 72) for E. stracheyi. The nucleotide divergence between sequences of the 6 species in pairwise comparisons was calculated and the result showed that the variable site could be detected in each pairwise comparison of sequences. Also, there were 8 point mutations in the 5.8S coding region.; Conclusion: nrDNA ITS sequences can be used as the molecular markers to identify the Tibetan herb Chuan-Bu and such Traditional Chinese Medicines from the same genus Euphorbia as E. lathyris, E. humifusa and E. pekinensis.;
AIM OF THE STUDY: Based on the authors' collection of specimens used as jie-ji in local Tibetan areas, China, and taxonomic determination, this paper aims to give a list of medicinal plants as jie-ji, formally identify the ones recognized as jie-ji ga-bao or jie-ji na-bao and to offer basic data for further studies on these Tibetan herbs.MATERIALS AND METHODS: Local herbalists were visited in Tibetan areas, China to observe which plants were being used as jie-ji. Samples of the indigenous plants were collected at the same time. Also, the medicinal plants as jie-ji were taxonomically identified.
RESULTS: A list of medicinal plants including 10 species of jie-ji in local Tibetan areas is given, including their morphological pictures used for identification.
CONCLUSIONS: The origin of jie-ji is from 10 species of the Section Cruciata, Genus Gentiana (Gentianaceae). five species with dark blue flowers are used as jie-ji na-bao, the other five with white flowers are used as jie-ji ga-bao. Also, Gentiana macrophylla Pall. with dark blue flowers in the Section Cruciata, Genus Gentiana is not the original plant of jie-ji na-bao. The species endemic to the province are used as the original plants of jie-ji only in local Tibetan area of the province. Finally, the drug use of jie-ji in Traditional Tibetan Medicine is reasonable and it is efficacious.
AIM OF THE STUDY: Based on the authors' collection of specimens used as jie-ji in local Tibetan areas, China, and taxonomic determination, this paper aims to give a list of medicinal plants as jie-ji, formally identify the ones recognized as jie-ji ga-bao or jie-ji na-bao and to offer basic data for further studies on these Tibetan herbs. MATERIALS AND METHODS: Local herbalists were visited in Tibetan areas, China to observe which plants were being used as jie-ji. Samples of the indigenous plants were collected at the same time. Also, the medicinal plants as jie-ji were taxonomically identified. RESULTS: A list of medicinal plants including 10 species of jie-ji in local Tibetan areas is given, including their morphological pictures used for identification. CONCLUSIONS: The origin of jie-ji is from 10 species of the Section Cruciata, Genus Gentiana (Gentianaceae). five species with dark blue flowers are used as jie-ji na-bao, the other five with white flowers are used as jie-ji ga-bao. Also, Gentiana macrophylla Pall. with dark blue flowers in the Section Cruciata, Genus Gentiana is not the original plant of jie-ji na-bao. The species endemic to the province are used as the original plants of jie-ji only in local Tibetan area of the province. Finally, the drug use of jie-ji in Traditional Tibetan Medicine is reasonable and it is efficacious.
The changes of the immune function of rheumatoid arthritis before and after the Tibetan medicated-bath was observed. It showed a higher level of the rheumatoid factor (RF) titre, immunoglobulin (Ig) G, M, A and CD4 cells, but the CD8 cells was obviously lower before the treatment. Clinical data indicated that the medicated-bath had significant effective rate. In order to elucidate the mechanism of the medicated-bath upon rheumatoid arthritis the RF titre, Ig level, complement C3, 3H-TdR incorporated with lymphocytes transformation and CD3, CD4, CD8 cell level were assayed. Results showed that RF titre decreased after the bath and the negative transforming rate reached 70.6%, Ig level obviously dropped as well as the number of CD4 cells while CD8 cell level increased. The transforming stimulation index of lymphocyte cells obviously decreased. All of the above mentioned showed that there was a higher concentration of the enhancing factor of interleukin-2 (IL2-EF) involved in lymphocyte culture of rheumatoid arthritis patients. They suggested that the Tibetan medicated-bath had an immunomodulating effect on rheumatoid arthritis patients through increasing the level of CD8 cells and reducing CD4 cells.
Young adolescents who experience stress may also exhibit negative behaviors at school. Students whose misbehavior causes an interruption to classroom learning may be sent to the office and, as a result, lose instructional time and learning. The goal of this quasi-experimental pilot study was to determine if mindfulness training would decrease the number of office discipline referrals for middle grades students with a high number of office discipline referrals. The treatment required students to use a Muse brain-sensing headband paired with an app to train them to focus on calming and self-regulating behaviors. Data analysis indicated a statistically significant correlation between using the headband for 3 min a week and a lower number of times students were sent to the office for behavior redirection. Research with a larger sample size is recommended.
<br>Display Omitted<br>• Optimal dosages of phosphate and potassium fertilizer on <b>R. tanguticum</b> were firstly explored. • The U-shaped fluctuation curve of total anthraquinone content is firstly proposed. • Optimization of chromatographic columns was firstly proposed when detecting index constituents. • Total anthraquinone content of two-year-old plants had reached <b>Chinese Pharmacopoeia</b> standard.<br>The dried root of <b>Rheum tanguticum</b> plays an important role in formulations and prescriptions in traditional Chinese medicine and Kampo medicine. Due to over-exploitation, <b>R. tanguticum</b> resources have decreased sharply in recent years. The main objective of our investigation (a 3-year field experiment) was to explore the effect of different levels of phosphorus (superphosphate) and potassium (potassium sulfate) fertilizer on the biomass (root fresh weight, root increment, and root dry weight), yield, dry matter content, and anthraquinone content of this plant at different harvesting stages (green stage, growth stage, and wilting stage) under alpine conditions. The root fresh weight and root dry weight increased significantly at the wilting stage following treatment with 90 kg P2O5/ha (100% and 59%, respectively) in 2016 and 75 kg K2O/ha (43% and 41%, respectively) in 2015 compared to the control. The yield of root dry weight obtained from three-year-old <b>R. tanguticum</b> plants was 9200 kg/ha when 90 kg P2O5/ha of phosphorus fertilizer was applied, and 10,400 kg/ha when 75 kg K2O/ha of potassium fertilizer was applied. This yield reached a maximum at the wilting stage. The anthraquinone content of two-year-old <b>R. tanguticum</b> plants had already reached the standard level of the <b>Chinese Pharmacopoeia</b>; however, three-year-old plants had double the anthraquinone content of two-year-old plants. Phosphorus and potassium fertilizers had no obvious influence on the anthraquinone content of <b>R. tanguticum</b> at the same harvesting stage.
Ethnopharmacological relevance: Saussurea laniceps Hand.-Mazz. (SL) has long been used under the herbal name Tibetan 'Snow Lotus' for the treatment of rheumatoid arthritis, stomachache and dysmenorrhea in Tibetan folk medicine. Since herbal medicine (HM) is a synergistical system with multiple components, both of the metabolism and pharmacokinetic studies of HM are interdependent. This study aimed to develop an integrated strategy based on the UPLC-DAD-QTOF-MS technique for metabolism and pharmacokinetic studies of HM.Material and methods: SL was used here as a test herb to verify the feasibility of the proposed strategy. SL was administered to rats, then, the blood plasma, urine and feces were analyzed to determine the metabolic profiles. Using our strategy, umbelliferone and scopoletin were evaluated to be the key bioactive components. Their pharmacokinetic parameters were measured and biotransformation pathways were elucidated.Results: After oral administration of SL to rats, 17 components in blood, 10 components in urine and 2 components in feces were identified and characterized using our UPLC-DAD-QTOF-MS method. Umbelliferone, scopoletin and their metabolites were found to be the major components involved in the metabolism process. Literature reports also suggest that umbelliferone and scopoletin are responsible for the therapeutic effects of SL, thus these two components were selected as the active markers for pharmacokinetic study. In the test of validity, the established method presented good linearity with R-2> 0.99. The relative standard deviation value was below 13.9% for precision, and recovery studies for accuracy were found to be within the range 91.8-112.5%.Conclusion: The present strategy offers, simultaneously, precision in quantitative analysis (metabolism study) and accuracy in quantitative analysis (pharmacokinetic study) with greater efficiency and less costs, which is therefore reliably used for integrated metabolism and pharmacokinetic studies of HM. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
Zuotai is an essential part in Tibetan patent medicine, which plays an important role in treating diseases. This paper introduced the invention, preparing process, use, effectiveness, and safety of Zuotai, aimed to provide an insight for traditional Chinese medicine when using heavy mental within Chinese patent medicine.
Nitraria tangutorum Bor., having edible berries, is valued for reputed health benefits in Qinghai-Tibet plateau. The phytochemical research on the fruit juice of N. tangutorum led to the isolation of twenty-six compounds including five new compounds, tangutorids A-D (1, 2, 3a, and 3b), and (3E,5E)-7-O-β-glucosyl-4-(2-methoxy-2-oxoethyl)hepta-3,5-dienoic acid (15). The structures of these compounds were elucidated through comprehensive spectroscopic analyses. Tangutorids A-F were the first examples of glucose-derived β-carbolines from natural products. The biogenetic pathways of 1-8 were proposed to involve Pictet-Spengler reactions and described starting from the co-isolated tryptophan (10) and corresponding aldehydes. All isolates were evaluated for their antioxidant and α-glucosidase inhibitory activities. Compounds 21, 22, and 24 showed antioxidant activity with SC50 values ranging from 12.2±1.9 to 30.4±2.7μg/mL, and compound 1 showed strong α-glucosidase inhibitory effect with IC50 value of 63.3±4.6μg/mL.
Asterothamnus centrali-asiaticus, a kind of characteristic shrub abundant in grassland and desert areas, has been used as forage fodder for camels and goats in Central Asia, and this plant also plays a critical role in the maintenance of desert grassland ecosystems as a result of its tolerance to poor soils and sand burial. However, its chemical composition has been rarely reported. In this study, phytochemical investigation of this pasturage was performed and three new triterpenoid saponins (1-3) were isolated together with nine known triterpenoid saponins (4-12) using preparative two-dimensional reversed-phase liquid chromatography/hydrophilic interaction chromatography (2D RPLC/HILIC). Their structures were elucidated via diverse spectroscopic analyses, including infrared (IR) spectrometry, high-resolution electrospray ionization mass spectrometry (HR-ESIMS), and one-dimensional (1D) and 2D nuclear magnetic resonance (NMR). All isolated triterpenoid saponins (1-12) were reported from this genus for the first time, and they were further evaluated for their cytotoxicity against four cancer cell lines (A549, HepG2, MGC-803, and MFC), which indicated that compound 11 showed potent cytotoxicity against the HepG2 cell line, with an IC50 value of 6.85 μg/mL.
A novel molecular iodine-catalyzed protocol for the construction of thiocarbamates from readily available sodium sulfinates, isocyanides, and water has been described. The present methodology offers a facile and practical route to a variety of thiocarbamates in moderate to good yields with favorable functional group tolerance by use odorless sodium sulfinates as the sulfur source. The mechanistic studies suggest the present transformation involves a radical process.
A novel and efficient visible-light-induced C(sp2)-H/N-H cross-dehydrogenative coupling (CDC)-amination with both primary and secondary aliphatic amines at room temperature in air is developed. This photocatalytic reaction allows the direct formation of 3-aminoquinoxalin-2(1 H)-ones via CDC-amination in the absence of any external oxidant added from outside. Preliminary mechanistic studies reveal that the present reaction proceeds through a radical process.
ObjectiveTo assess the effectiveness of mindfulness-based stress reduction (MBSR) for chronic insomnia and combined depressive or anxiety symptoms of older adults aged 75 years and over.
Design
A randomized, controlled, single-blind clinical trial.
Patients and Methods
Participants included 60 adults aged 75 years and over with chronic insomnia. Participants were randomly assigned to the eight-week MBSR group or the wait-list control group. Assessments using the Pittsburgh Sleep Quality Index (PSQI), Self-rating Anxiety Sale (SAS), and Geriatric Depression Scale (GDS) were taken at baseline and post-treatment. For each outcome measure, a repeated measures analysis of variance was used to detect changes across assessments.
Results
There was a significant time × group interaction for the PSQI global score (P = .006); the MBSR group had a decrease in the PSQI global score (Cohen׳s d = 1.12), while the control group did not (Cohen׳s d = −0.06). Among the PSQI components, there was a significant time × group interaction for daytime dysfunction (P = .048); Cohen׳s d of the MBSR group was 0.76, while Cohen׳s d of control group was −0.04. There was no significant time × group interaction for the SAS score (P = .116), while for the GDS there was a significant time × group interaction (P = .039); the Cohen׳s d value for the MBSR group was 1.20, and it was 0.12 for the control group.
Conclusion
This study demonstrated that the MBSR program could be a beneficial treatment for chronic insomnia in adults aged 75 years and older.
Because they generate excellent images, nanoparticles (NPs), especially biosynthesized NPs, provide a new solution for tumor imaging. In this research, we unveil a novel type of biosynthesized NPs featuring multicolor fluorescence. These NPs exhibit little cytotoxicity to cells. The explored NPs, designated Zn-ZFP-GST NPs (Zinc NPs in abbreviation), are generated from leukemia cells treated with a Zn2+ solution, while zinc-finger protein and glutathione S-transferase (GST) were also identified in the Zinc NPs. Under near-UV illumination, the Zinc NPs simultaneously emit green, yellow, and red fluorescence. In addition, the intensity of the fluorescence increases with the existence of sulfides. Besides, the NPs are encapsulated by microvesicles (MVs) shed from the plasma membrane. As observed in whole-body research of nude mice, the NP-MVs migrate via blood circulation and are distinguished by their fluorescent signals. Furthermore, the folic acid (FA) &AVR2 (human VEGF antibody)-coated NP-MVs are exploited to target the tumor location, and the feasibility of this approach has been confirmed empirically. The Zinc NPs shed light on an alternative solution to tumor detection.
<br>Display Omitted<br>• A new coupled method of stable isotope-labeling derivatization with UA-DLLME was reported. • Simultaneous determination of multiple neurotransmitters with UHPLC-MS/MS. • Heavy labeled d3-MASC standards were used as the internal standards for quantification. • The method was sensitive, accurate and low matrix effect. • Application for neurotransmitters dynamic changes in rats brain microdialysates.<br>In this work, for the first time, a new hyphenated technique of stable isotope-labeling derivatization-ultrasound-assisted dispersive liquid-liquid microextraction has been developed for the simultaneous determination of monoamine neurotransmitters (MANTs) and their biosynthesis precursors and metabolites. The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry detection using multiple-reaction monitoring mode. A pair of mass spectrometry sensitizing reagents, d0-10-methyl-acridone-2-sulfonyl chloride and d3-10-methyl-acridone-2-sulfonyl chloride, as stable isotope probes was utilized to facilely label neurotransmitters, respectively. The heavy labeled MANTs standards were prepared and used as internal standards for quantification to minimize the matrix effects in mass spectrometry analysis. Low toxic bromobenzene (extractant) and acetonitrile (dispersant) were utilized in microextraction procedure. Under the optimized conditions, good linearity was observed with the limits of detection (S/N > 3) and limits of quantification (S/N > 10) in the range of 0.002-0.010 and 0.015-0.040 nmol/L, respectively. Meanwhile, it also brought acceptable precision (4.2-8.8%, peak area RSDs %) and accuracy (recovery, 96.9-104.1%) results. This method was successfully applied to the simultaneous determination of monoamine neurotransmitters and their biosynthesis precursors and metabolites in rat brain microdialysates of Parkinson's disease and normal rats. This provided a new method for the neurotransmitters related studies in the future.
A new diarylheptanoid, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-6-Oacetylglucoside (<i>1</i>), together with two known diarylheptanoids, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside (<i>2</i>) and hirsutanonol (<i>3</i>), were isolated from Saxifraga tangutica. The structures of <i>1-3</i> were elucidated using 1D and 2D NMR spectral data, including high-resolution mass spectra (HR-ESI-MS). It was found that the new compound was acetyl-substituted (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptan-3-one-5-O-β-D-glucopyranoside.
A new isocoumarin, along with 10 known compounds, was isolated from the aerial parts of Aconitum gymnandrum. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Among the known compounds, compound 11 was obtained as a natural product for the first time, which was previously reported as a synthetic product. In addition, compounds 1-5, 7 and 9 were tested for their cytotoxicity against four human cancer cell lines. The results showed that compounds 3, 4 and 7 displayed cytotoxicity against lung cancer A549 and gastric cancer MGC80, respectively, whereas 5 and 9 showed selective cytotoxicity against hepatocellular carcinoma HepG2.
A new isocoumarin, along with 10 known compounds, was isolated from the aerial parts of Aconitum gymnandrum. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Among the known compounds, compound 11 was obtained as a natural product for the first time, which was previously reported as a synthetic product. In addition, compounds 1-5, 7 and 9 were tested for their cytotoxicity against four human cancer cell lines. The results showed that compounds 3, 4 and 7 displayed cytotoxicity against lung cancer A549 and gastric cancer MGC80, respectively, whereas 5 and 9 showed selective cytotoxicity against hepatocellular carcinoma HepG2.
<br>Display Omitted<br>• Two new monoterpenes named sibiscolactons A and B (<b>1</b> and <b>2</b>) were isolated from <b>Sibiraea laevigata</b>. • New compounds’ absolute configurations were established by electronic circular dichroism (ECD) calculations. • Eight known phenylpropanoids (<b>3</b>-<b>10</b>) were also obtained from the title plant. • <b>1</b>-<b>10</b> were evaluated for their cytotoxic activity. • Compound <b>3</b> displayed moderate cytotoxicity with IC50 values ranging from 10.8 to 49.2 μg mL−1.<br>Chemical investigation of the ethanol extract of the stalks and infructescence of <b>Sibiraea leavigata</b> led to the isolation of two new monoterpenes named (4<b>R</b>)-2-(2-hydroxy-4-methyl-3-pentenyl)furan-2(5<b>H</b>)-one (<b>1</b>) and (2<b>R</b>,4<b>R</b>)-2-(2-hydroxyethyl)-4-(2-methyl-1-propenyl)furan-5<b>H</b>-2-one (<b>2</b>) along with eight known phenylpropanoids (<b>3-10</b>). Their structures were established on the basis of the interpretation of spectroscopic data and electronic circular dichroism (ECD) calculations. In addition, all of these isolates were evaluated for their cytotoxic activity. The results showed that compound <b>3</b> displayed moderate cytotoxicity with IC50 values ranging from 10.8 to 49.2 μg mL−1 against five cell lines. While <b>1</b> showed selective promotion effects on proliferation of gastric cancer MGC803 and RSC96 cell lines.
Phytochemical investigation on <b>Asterothamnus centrali-asiaticus</b> afforded four new sesquiterpenes, asterothamnones A-D (<b>1</b>-<b>4</b>), and three new benzofuran derivatives (<b>5</b>-<b>7</b>) together with ten known compounds (<b>8</b>-<b>17</b>). Their structures were elucidated using 1D and 2D NMR and X-ray diffraction analyses. Compounds <b>1</b>-<b>4</b> were verified to be unusual eudesmane sesquiterpenes possessing 4,6-dien-3-one or 1,4,6-triene-3-one conjugated system. The absolute configurations of compounds <b>1</b>-<b>8</b> were established by means of calculated electronic circular dichroism (ECD). Furthermore, all isolates were evaluated for their cytotoxic and anti-oxidant activities. Results showed that <b>10</b>, <b>12</b> and, <b>14</b> exhibited cytotoxic activity against HepG2 cancer cells and <b>14</b> displayed cytotoxicity against MGC-803 cancer cells. Compounds <b>10</b> and <b>17</b> showed anti-oxidant effect.<br><br>Display Omitted
Substance P (SP) is a candidate mediator along the brain-skin axis and can mimic the effects of stress to regulate melanogenesis. Previously, we and others have found that the regulation of SP for pigmentary function was mediated by neurokinin 1 receptor (NK1R). Emerging evidence has accumulated that psychologic stress can induce dysfunction in the cutaneous serotonin 5-hydroxytryptamine (5-HT)-5-HT1A/1B receptor system, thereby resulting in skin hypopigmentation. Moreover, NK1R and 5-HTR (except 5-HT3) belong to GPCR. The present study aimed at assessing the possible existence of NK1R-5-HTR interactions and related melanogenic functions. Western blot and PCR detection revealed that SP reduced expression of 5-HT1A receptor via the NK1 receptor. Biochemical analyses showed that NK1R and 5-HT1AR could colocalize and interact in a cell and in the skin. When the N terminus of the NK1R protein was removed NK1R surface targeting was prevented, the interaction between NK1R-5-HT1AR decreased, and the depigmentation caused by SP and WAY100635 could be rescued. Importantly, pharmaceutical coadministration of NK1R agonist (SP) and 5-HT1A antagonist (WAY100635) enhanced the NK1-5-HT1A receptor coimmunoprecipitation along with the depigmentary response. SP and WAY100635 cooperation elicited activation of a signaling cascade (the extracellular, regulated protein kinase p-JNK signaling pathway) and inhibition of p70S6K1 phosphorylation and greatly reduced melanin production in vitro and in vivo in mice and zebrafish. Moreover, the SP-induced depigmentation response did not be occur in 5-htr1aa+/- zebrafish embryos. Taken together, the results of our systemic study increases our knowledge of the roles of NK1R and 5-HT1AR in melanogenesis and provides possible, novel therapeutic strategies for treatment of skin hypo/hyperpigmentation.-Wu, H., Zhao, Y., Huang, Q., Cai, M., Pan, Q., Fu, M., An, X., Xia, Z., Liu, M., Jin, Y., He, L., Shang, J. NK1R/5-HT1AR interaction is related to the regulation of melanogenesis.
Traditional Tibetan medicine provides an abundant source of knowledge on human ailments and their treatment. As such, it is necessary to explore their active single compounds used to treat these ailments to discover lead compounds with good pharmacologic properties. In this present work, animal medicine, Osteon Myospalacem Baileyi extracts have been separated using a two-dimensional preparative chromatographic method to obtain single compounds with high purity as part of the following pharmacological research. Five high-purity cyclic dipeptides from chromatography work were studied for their dihydroorotate dehydrogenase inhibitory activity on recombinant human dihydroorotate dehydrogenase enzyme and compound Fr. 1-4 was found to contain satisfying inhibition activity. The molecular modeling study suggests that the active compound Fr. 1-4 may have a teriflunomide-like binding mode. Then, the energy decomposition study suggests that the hydrogen bond between Fr. 1-4 and Arg136 can improve the binding mode to indirectly increase the van der Waals binding energy. All the results above together come to the conclusion that the 2, 5-diketopiperazine structure group can interact with the polar residues well in the active pocket using electrostatic power. If some proper hydrophobic groups can be added to the sides of the 2, 5-diketopiperazine group, it is believed that better 2, 5-diketopiperazine dihydroorotate dehydrogenase inhibitors will be found in the future.
Pages |