CHEMISTRY OF NATURAL COMPOUNDS
·
2020
·Vol. 56
·期 5
·821-826
·
IF 0.653
Shao Jin,Zhao Tong,Ma Hui-Ping,Jia Zheng-Ping,Jing Lin-Lin
A convergent synthesis route of 6-hydroxygenistein (6-OHG) was reported, starting from cheap and readily available biochanin A, via methylation, bromination, methoxylation, and demethylation. The structure of the products was confirmed by MS, IR, 1 H NMR, and 13 C NMR analysis. The antiradical activity of 6-OHG was determined using six different methods, namely, DPPH assay, ABTS assay, nitric oxide assay, superoxide assay, reducing power assay, and phosphomolybdenum assay using ascorbic acid (V C ) as positive control. The results show that 6-OHG possesses similar or greater antiradical activity than V C . In conclusion, 6-OHG can be useful as an antioxidant agent.
研究领域:
有机化学
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药物化学
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天然产物化学
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DOI
高影响因子
ELECTRONIC JOURNAL OF BIOTECHNOLOGY
·
2025
·
IF 2.5
Yi Li,Jiacheng Tang,Kaixiang Xin,Zongda Chen,Lele Zhao,Yifan Zhao,Yinbiao Xu,Pei Zhou,Yang Sun,Yupeng Liu,Hua Li
Background Nicotinic acid dehydrogenase possesses the capability to convert nicotinic acid into 6-hydroxynicotinic acid, a compound of significant research value as a pharmaceutical intermediate. The extraction of nicotinic acid dehydrogenase is primarily performed by strains. However, the enzyme activity of the strains reported currently is relatively low, and their potential to catalyze the production of 6-hydroxynicotinic acid is insufficient to meet industrial requirements. Results Due to the revealing properties of 6-hydroxynicotinic acid, this study proposes a technique for calculating the luminescence intensity of colonies, which is based on a fluorescence spectrometer. The developed method establishes a reliable linear relationship (88.2%) between the luminescence intensity and enzyme activity. Consequently, it has been employed to screen strains that produce nicotinate dehydrogenase. This screening approach allows for the evaluation of about 500 enzyme-producing strains daily, presenting an efficient strategy for screening. Conclusions Through this approach, a novel high enzyme activity strain producing nicotinic acid dehydrogenase, Pseudomonas poae have been obtained, which designated as HD530. After process optimization, it was utilized to produce 6-hydroxynicotinic acid, achieving a high yield of 155.45 g/L within 72 h, meeting the requirements for industrial production. The effectiveness and potential of this technique lie in its application for strain screening and improvement.
研究领域:
微生物学
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生物技术
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制药工程
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产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Linquan Dai,Bo Feng,Mengyan Tang,Yuangan Chen
It is challenging to separate between molybdenite and chalcopyrite due to their comparable hydrophobic characteristics. Inorganic depressants were previously used to separate two minerals, but the results were unsatisfactory and polluted the environment. In this study, the molybdenite and chalcopyrite were separated using a highly effective and ecologically safe depressant, 2,4-Diamino-6-hydroxypyrimidine (DAHP). According to the single mineral experiment, chalcopyrite is totally depressed while molybdenite has superior floatability. The efficacy of DAHP as the depressant was validated by further artificially mixed mineral flotation experiments, indicating the possibility of separating chalcopyrite and molybdenite. The adsorption capacity experiment results showed that the adsorption capacity of DAHP on the surface of chalcopyrite was greater than that on the surface of molybdenite. Zeta potential experiment results show that DAHP is adsorbed on the surface of chalcopyrite and molybdenite through static electrostatic interactions . X-ray photoelectron spectroscopy (XPS) experiment results show that DAHP is mainly adsorbed on chalcopyrite surface through –NH 3 + group, which hinders the adsorption of kerosene. The electrostatic contact between DAHP and molybdenite has the least effect on kerosene adsorption. This study shows that DAHP has the potential to separate chalcopyrite and molybdenite as an efficient and environmentally friendly depressant.
研究领域:
矿物加工工程
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环境科学
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产品关联
DOI
高影响因子
MOLECULES
·
2018
·Vol. 23
·期 12
·3214
·
IF 3.098
Jun Cao,Huimin Wang,Wei Zhang,Fuliang Cao,Geli Ma,Erzheng Su
Ginkgo bilobaleaves have various health benefits due to the presence of bioactive compounds such as polyprenyl acetates, flavonoids, and terpene trilactones. However, there is little literature reported on the aromatic acids inGinkgo bilobaleaves. In this work, five aromatic acids including shikimic acid (SA), 6-hydroxykynurenic acid (6-HKA), protocatechuic acid (PA), gallic acid (GAA), andp-hydroxybenzoic acid (PHBA) were simultaneously extracted fromGinkgo bilobaleaves by employing the green deep eutectic solvents (DESs). A DES tailor-made from xylitol, glycolic acid and 1,5-pentanedioic acid at a molar ratio of 1:3:1 with 50% (w/w) water addition, named as NGG50, gave higher extraction yields for the five aromatic acids. Main factors affecting the extraction process were further optimized. The highest extraction yields of SA, GAA, 6-HKA, PA, and PHBA were 94.15 ± 0.96 mg/g, 332.69 ± 5.19 μg/g, 25.90 ± 0.61 μg/g, 429.89 ± 11.47 μg/g and 67.94 ± 0.37 μg/g, respectively. The NGG50-based extraction process developed here was a successful attempt of simultaneously extracting five aromatic acids fromGinkgo bilobaleaves for the first time, which could provide a new exploitation direction ofGinkgo bilobaleaves.Keywords:deep eutectic solvents;Ginkgo bilobaleaves;simultaneous extraction;shikimic acids;6-hydroxykynurenic acid
研究领域:
药学化学
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分析化学
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植物科学
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产品关联
DOI
PubMed
高影响因子
Natural Product Communications
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2025
·
IF 1.4
Zhuowei Shen,Yanhong Chen,Kui Zeng,Haihong Hu,Jie Pan,Mingcheng Xu,Kaifeng He,Fengting Ou,Lushan Yu,Su Zeng,Lu Chen
Background6-hydroxykynurenic acid (6-HKA), isolated from Ginkgo biloba leaves, has demonstrated neurorestorative properties against cerebral ischemia in middle cerebral artery occlusion (MCAO) mice models. However, our previous studies showed that 6-HKA was difficult to penetrate the blood brain barrier (BBB) to exert its pharmacological effects in rats. Therefore, this study aims to investigate the pharmacokinetics and cerebral cortex distribution of 6-HKA in MCAO mice, to determine whether the ability of 6-HKA to cross the BBB is contingent upon barrier integrity.MethodsThis study established and validated the ultra-performance liquid chromatography tandem mass spectrometric (UPLC-MS/MS) methods for the quantification of 6-HKA in mouse plasma and brain, and investigated the pharmacokinetics and cerebral cortex distribution of 6-HKA in MCAO mice and sham-operated mice.ResultsThis study demonstrates that the mean residence time (MRT0−t) of 6-HKA in the MCAO group was significantly prolonged compared to the sham-operated group, and there was a higher distribution of 6-HKA in the ischemic cerebral cortex than in the contralateral normal cerebral cortex.ConclusionThis study illustrated that in MCAO mice, the prolonged MRT0−t of 6-HKA and the increased permeability of BBB made the accumulation of 6-HKA in the ischemic cerebral cortex, thereby enabling 6-HKA to exert neurorestorative effects.
研究领域:
神经科学
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药理学
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生物化学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Rui Ma,Jinrong Bai,Yuting Huang,Zhiqiu Wang,Yongju Xu,Yan Huang,Kai Zhong,Yina Huang,Hong Gao,Qian Bu
Peanut (Arachis hypogaea) peptides have various functional activities and a high utilization value. This study aims to isolate and characterize antioxidant peptides from peanut protein hydrolysates and further evaluate their neuroprotection against oxidative damage to PC12 cells induced by 6-hydroxydopamine (6-OHDA). After the peanut protein was hydrolyzed with pepsin and purified using ultrafiltration and gel chromatography, six peptides were identified and sequenced by high-performance liquid chromatography (HPLC) and liquid chromatography–tandem mass spectrometry (LC–MS/MS). Out of these six peptides, Pro-Gly-Cys-Pro-Ser-Thr (PGCPST) exhibited a desirable antioxidant capacity, as determined using the 1,1-diphenyl-2-picrylhydrazyl, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, and hydroxyl radical scavenging assays. Moreover, our results indicated that the peptide PGCPST effectively increased the cell viability and reduced the cell apoptosis in 6-OHDA-induced PC12. RNA sequencing further showed that the neuroprotective effect of the peptide PGCPST was mediated via sphingolipid metabolism-related pathways. With further research efforts, the peptide PGCPST was expected to develop into a new neuroprotective agent.
研究领域:
食品科学
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药理学
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神经科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHARMACY AND PHARMACOLOGY
·
2021
·Vol. 74
·期 1
·22-31
·
IF 3.765
Shen Zhuowei,Hu Haihong,Pan Jie,Xu Mingcheng,Ou Fengting,He Kaifeng,Zeng Kui,Yao Jianbiao,Wang Ruwei,Lou Yan,Zeng Su
Objectives6-Hydroxykynurenic acid (6-HKA) is an organic acid component in extracts of Ginkgo biloba leaves and acts as a major contributor to neurorestorative effects, while its oral bioavailability was low. Therefore, using prodrug method to improve the bioavailability and brain content of 6-HKA is significant.MethodsThree structural modified compounds of 6-HKA were synthesized, and ultra performance liquid chromatography-tandem mass spectrometry methods for quantification of these structural modified compounds in rat plasma and rat brain homogenate were established and comprehensively validated. The methods were effectively applied to investigate the effects of structural modification on apparent permeability coefficients in cells, the pharmacokinetics and the brain distribution in rats.Key findingsThe results illustrated that esterification can greatly improve the apparent permeability coefficient and bioavailability of 6-HKA. Comparing with direct oral administration of 6-HKA, the bioavailability of isopropyl ester was greatly improved (from 3.96 ± 1.45% to 41.8 ± 15.3%), and the contents of 6-HKA in rat brains (49.7 ± 9.2 ng/g brain) were significantly higher after oral administration.ConclusionsThe bioavailability and the brain content of 6-HKA can be improved by the prodrug method. Among three structural modified compounds, isopropyl-esterified 6-HKA was the most promising treatment.
研究领域:
药理学
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神经科学
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药物代谢动力学
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2019
·
IF 2.813
Zhuowei Shen,Kaifeng He,Mingcheng Xu,Kui Zeng,Jie Pan,Fengting Ou,Jianbiao Yao,Ruwei Wang,Su Zeng
A sensitive and specific bioanalytical method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantification of 6-hydroxykynurenic acid (6-HKA) in a small quantity of rat plasma has been developed and comprehensively validated. Tolbutamide (Tol) was used as the internal standard (IS). An aliquot of 50 μL rat plasma sample was deproteinized by 150 μL methanol, and then 100 μL of its supernatant was mixed with 100 μL water after centrifugation . Chromatographic separation was performed on a ZORBAX Eclipse Plus C 18 Rapid Resolution HD column (2.1 mm × 100 mm, 1.8 μm) with a gradient mobile phase consisting of water containing 2 mM ammonium formate and methanol at a flow rate of 0.2 mL/min over a total run time of 5.0 min. The mass spectrometer was operated under multiple reactions monitoring (MRM) mode with the transitions m / z 206.1 → 160.0 for 6-HKA and m/z 269.0 → 170.0 for Tol. The linear range was 2.5–250 ng/mL with the square regression coefficient (r 2 ) of 0.997. The lower limit of quantification (LLOQ) was 2.5 ng/mL (Relative Error, RE +1.6% and RSD 4.8%, n = 5). The intra- and inter-day precision and accuracy was <13.3%. The mean recovery of 6-HKA in rat plasma was between the range of 99.3–103.4%. This method was successfully applied to study the pharmacokinetics of 6-HKA in rats after oral administration at a single dose of 20.0 mg/kg and after tail intravenous injection at a single dose of 2.0 mg/kg. Pharmacokinetic parameters bioavailability, C max, oral , T max, oral , AUC 0–24h, oral , AUC 0–∞, oral , AUC 0–24h, iv and AUC 0–∞, iv were 3.96%, 152.0 ± 85.5 ng/mL, 0.4 ± 0.1 h, 340.0 ± 136.3 ng/mL ∗ h, 369.5 ± 135.0 ng/mL ∗ h, 906.6 ± 324.1 ng/mL*h and 932.9 ± 336.5 ng/mL ∗ h, respectively.
研究领域:
分析化学
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药理学
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生物医学
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产品关联
DOI
PubMed
高影响因子
XENOBIOTICA
·
2021
·
IF 1.908
Jadera Talap,Zhuowei Shen,Jing Nie,Jie Pan,Mingcheng Xu,Kui Zeng,Kaifeng He,Fengting Ou,Houhong He,Jianbiao Yao,Ruwei Wang,Lushan Yu,Su Zeng
6-Hydroxykynurenic acid (6-HKA) is a nitrogen-containing phenolic acid compound in Ginkgo biloba leaves. The pharmacological activities of 6-HKA have been reported and shown that 6-HKA has the potential to become a therapeutic drug and may play an important role in the treatment of nervous system diseases. However, there are few studies on the drug metabolism and transport of 6-HKA. The aim of this study is to investigate the in vitro metabolism of 6-HKA and its interaction with multiple important drug transporters.The in vitro metabolism experiments in the present study demonstrate that 6-HKA might not undergo phase-I or phase-II metabolism in hepatic microsomes/S9 of rats. In addition, some drug transporters, including OAT1/3, OCT2, MDR1, OATP1B1, MATE1/2K and OCTN2, were investigated. The cellular uptake assays indicate that 6-HKA exhibits inhibition to the transport of classical substrates mediated by OAT3, OCT2, MATE2K and OCTN2 but has no significant effect on the transport of substrates mediated by MDR1, OAT1, OATP1B1 or MATE1. Further investigation of cellular accumulation assays shows that 6-HKA might be the substrate of OAT3, but not OCT2 or OCTN2. The bidirectional transport study suggests that 6-HKA is not a substrate of MDR1.The information about the in vitro metabolism of 6-HKA and the interaction between 6-HKA and some transporters will help us to better understand the pharmacokinetic properties of 6-HKA and provide reference for its pharmacodynamics, DDIs and drug-food interactions studies.
研究领域:
药理学
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药物代谢动力学
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生物化学
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产品关联
DOI
PubMed
高影响因子
PHYTOCHEMISTRY
·
2021
·
IF 4.072
Xudong Zhang,Xing Huang,Yan Li,Faqing Tao,Qinshi Zhao,Weiqi Li
Polar auxin transport (PAT) is essential to control root growth. Flavonoids are widely thought to be PAT inhibitors leading to short root developments. However, we found that the flavonoids scutellarin and scutellarein , which both have a 6-hydroxyl group unlike the structure of known flavonoid-PAT-inhibitors, promote PAT in roots. They increase root length; rescue the short roots induced by the PAT-specific inhibitor TIBA; enhance the expression of the PAT mediators PIN1 , PIN2 and AUX1 ; increase the auxin concentration at the quiescent center; and change the distribution of the meristem organizer WOX5. In contrast, rutin and naringenin , which have no 6-hydroxyl group and have different structural features in B-ring, shows the opposite/no effects. Our evidence suggests that flavonoids with and without a 6-hydroxyl group might result in opposite effects on root growth and thus act as chemical switches in regulating PAT.
研究领域:
植物学
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分子生物学
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DOI
PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2024
·Vol. 50
·期 8
·3821-3841
·
IF 2.8
Zhai Chenghan,Ma Zhengxiang,Wang Yanji
The preparation of caprolactam (CPL) from biomass as raw material is a very hot topic of current concern. In this paper, a new way to synthesize CPL from 5-hydroxymethylfurfural (HMF) was proposed, and the catalytic reaction of cyclization of the intermediate 6-hydroxycaproamide (6-HCM) was studied to provide a basis for the synthesis of bio-based CPL. A bimetallic catalyst, Ru–Co/TiO 2 , was prepared using the impregnation method and characterized using XRD, XPS, H 2 -TPR, and TEM. The investigation delves into the impact of various parameters, including metal loading, choice of solvent, solvent ratio, catalyst dosage, and reaction time, on the yield of the final product. The findings demonstrate a significant synergistic effect between Ru and Co in the bimetallic Ru 5 Co 6 /TiO 2 catalyst, leading to improved catalytic performance. Under the optimized reaction conditions (250 °C, 1 MPa N 2 , 1,4-dioxane: NH 3 ·H 2 O = 2:1 as the solvent ratio), the conversion rate of 6-HCM reaches 99.0%, with CPL yield of 62.2%.
研究领域:
化学工程
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催化材料
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY
·
2022
·Vol. 322
·期 6
·G553
·
IF 4.871
Yan-Yan Fan,Yue Zhang,Rui-Fang Fan,Tao Wang,Xiao Yu,Li-Fei Zheng,Jin-Xia Zhu
Download figureDownload PowerPoint Patients with Parkinson’s disease (PD) often suffer from delayed gastric emptying, but the underlying mechanism remains unclear. We have shown previously that a PD rat model comprising bilateral substantia nigra destruction by 6-hydroxydopamine (6-OHDA rats) exhibits gastroparesis with alteration of neural nitric oxide synthase (nNOS) and acetylcholine in gastric corpus. However, changes in pyloric motility in the 6-OHDA rats have not been characterized. Solid gastric emptying test, immunofluorescence, Western blot, and in vitro pyloric motility recordings were used to assess pyloric motor function in the 6-OHDA rats. The 6-OHDA-treated rats displayed delayed solid gastric emptying and a lower basal pyloric motility index. In the 6-OHDA rats, high K+-induced transient contractions were weaker in pyloric sphincters. Electric field stimulation (EFS)-induced pyloric sphincter relaxation was lower in the 6-OHDA rats. NG-nitro-l-arginine methyl ester (l-NAME), a nonselective inhibitor of NOS, markedly inhibited the EFS-induced relaxation in both control and 6-OHDA rats. Pretreatment of tetrodotoxin abolished the effect of EFS on the pyloric motility. In addition, nNOS-positive neurons were extensively distributed in the pyloric myenteric plexus, whereas the number of nNOS-immunoreactive neurons and the protein expression of nNOS were significantly decreased in the pyloric muscularis of 6-OHDA rats. However, sodium nitroprusside-induced pyloric relaxations were similar between the control and 6-OHDA rats. These results indicate that the pyloric sphincters of 6-OHDA rats exhibit both weakened contraction and relaxation. The latter may be due to reduced nNOS in the pyloric myenteric plexus. The dysfunction of the pyloric sphincter might be involved in the delayed gastric emptying.NEW & NOTEWORTHY Reduced nitrergic neurons in pyloric myenteric plexus potently contributed to the attenuated relaxation in 6-hydroxydopamine (6-OHDA) rats, subsequently affecting gastric emptying. SNP could well improve the relaxation of pylori in 6-OHDA rats. The present study provides new insight into the diagnosis and treatment of delayed gastric emptying in patients with PD.
研究领域:
神经科学
·
胃肠生理学
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DOI
PubMed
高影响因子
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