Akkermansia muciniphila-directed polyphenol chlorogenic acid intervention for obesity in mice

Akkermansia muciniphila play an important in ameliorating obesity but is not allowed for direct consumption in most countries.To date,microbiota-directed foods selectively promote the targeted human gut microbes,providing a strategy for A.muciniphila enhancement.Multiple studies have indicated the potential regulation of the polyphenol on A.muciniphila.Therefore,a polyphenol screening based on A.muciniphila upregulation was performed in mice.Chlorogenic acid(CGA)exhibited a greater response to A.muciniphila upregulation.Furthermore,we found that CGA did not directly promote A.muciniphila growth or mucin secretion.Microbiome and metabolomics revealed that the increased abundance of A.muciniphila resulted from the inhibition of CGA on Desulfovibrio and Alistipes and the influence of docosahexaenoic acid,β-hydroxybutyrate,and N-acetyl-lactosamine.Finally,to confirm the regulation of CGA on A.muciniphila under disease conditions,high-fat diet-fed mice were established.The results showed CGA promoted A.muciniphila growth,and we expectedly found that CGA suppressed the augment in body weight of mice,significantly attenuated adipose tissue abnormality,provided liver protection and improved gut barrier integrity.These results suggest that CGA inhibits the development of obesity.Overall,our results indicate that microbiota-directed food is a promising approach for the treatment of obesity.

Chlorogenic acid ameliorates heart failure by attenuating cardiomyocyte ferroptosis

Objective:To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides Oliv.(Du Zhong Ye),tea,and coffee,on cardiomyocyte ferroptosis and heart failure.Methods: We assessed the effect of CGA on cardiac function using a mouse model of heart failure induced by transverse aortic constriction(TAC).These indicators included the left ventricular ejection fraction(LVEF),fractional shortening(LVFS),end-systolic volume(LVESV),end-diastolic volume(LVEDV),end-systolic diameter(LVESD),and end-diastolic diameter(LVEDD).An isoprenaline hydrochloride(ISO)-induced H9c2 cardiomyocyte cell model was also established,and the cells were treated with various concentrations of CGA.To assess the effect of CGA on ferroptosis in cardiomyocytes,we measured cell viability and evaluated the levels of intracellular reactive oxygen species(ROS),ferrous ions(Fe^(2+)),and lipid peroxidation using fluorescent staining.To clarify the ferroptosis signaling pathway regulated by CGA,western blotting was used to examine the expression of ferroptosis biomarkers,specifically solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),in H9c2 cardiomyocytes and mouse myocardial tissues.Results: CGA significantly enhanced cardiac performance indices such as LVEF,LVFS,LVESV,LVEDV,LVESD,and LVEDD.H9c2 cardiomyocytes exposed to ISO showed decreased cell viability and increased ROS levels,Fe^(2+)content,and lipid peroxidation levels.However,CGA treatment significantly ameliorated these changes.Additionally,in both H9c2 cardiomyocytes and myocardial tissue obtained from mice with TAC,CGA increased the expression of ferroptosis-related proteins,including SLC7A11 and GPX4.Conclusion: CGA has the potential to enhance cardiac function and diminish lipid peroxidation and ROS levels in cardiomyocytes via the SLC7A11/GPX4 signaling pathway.This process alleviates ferroptosis in cardiomyocytes.These results provide new insights into the clinical use of CGA and the management of heart failure.

Establishment of an in vitro Tissue Culture and Rapid Propagation System using Lonicera hypoglauca and Content Assessment of Total Flavonoids and Chlorogenic Acid

Lonicera hypoglauca is a traditional Chinese medicinal plant.In this study,the tender young leaves of L.hypoglauca were used for the first time as the explants to establish a rapid in vitro propagation and regeneration system.The results revealed that the optimal time for disinfection of the explants was 8 min and the optimal medium for callus induction was MS+2,4-D 4.0 mg·L^(-1)+sucrose 30 g·L^(-1),with an average callus induction rate of 86.67%.The optimal medium to induce differentiation of callus to bud was MS+6-BA 1.0 mg·L^(-1)+NAA 0.10 mg·L^(-1)+sucrose 30 g·L^(-1),with an average germination rate of 83.33%.The optimal medium to induce multiplication was MS+6-BA 1.5 mg·L^(-1)+NAA 0.05 mg·L^(-1)+sucrose 30 g·L^(-1),with a multiplication coefficient of 5.42.The optimal medium for root induction was 1/2 MS+NAA 0.15 mg·L^(-1)+activated carbon 0.3 g·L^(-1)+sucrose 15 g·L^(-1),with an average rooting rate of 91.11%.The survival rate of tissue-cultured seedlings in nutrient soil cultivation medium was as high as 100%.The total flavonoid content and chlorogenic acid content in the explant,callus tissue and regenerated plant were 1.83%,2.27%,1.33%and 2.77%,1.83%,1.74%respectively.This study provides novel insights into the rapid propagation and mass production of L.hypoglauca seedlings at an industrial scale and that it exhibits important application value and future prospects.

Effects of Honeysuckle Chlorogenic Acid on Secretory Enzymes,Lipoxygenase A4,and Biochemical Indicators inModel Mice with Aluminum Induced Alzheimer's Disease

[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Methods]Chlorogenic acid was extracted from hon-eysuckle by ultrasound assisted alcohol extraction method.Seventy mice were randomly divided into normal group,model group,and low,me-dium and high dose groups of honeysuckle chlorogenic acid.All the mice in each group except for the normal group were given maltol aluminum by intraperitoneal injection to establish models of aluminum induced AD,continuously injected for 5 d and stopped for 2 d,totally poisoned for 8 weeks.Starting from the 5^(th) week of poisoning,the low,medium and high dose groups of honeysuckle chlorogenic acid were given honeysuck-le chlorogenc acid solution 40,80 and 160 mg/kg by gavage,respectively,while the normal group and the model group were fed with an equal volume of distilled water,all once daily,continuously gavaged until the end of the 8^(th) week.At the end of the experiment,the learning memory ability of the mice was tested by Y-type waler maze,and the number of tests required to reach the learning standard,the number of memory er-rors in 20 tests and the error rate of the mice were recorded.The brains of mice were taken to determine the contents of β-secretase,α-secre-tase,γ-secretase,LXA4 and acetylcholinesterase(AchE)in the homogenates of brain tissues by ELISA,and their blood was taken to deter-mine the biochemical indexes.[Results]Compared with the normal group,the number of learning tests,number of memory errors,error rate and the contents of β-secretase,γ-secretase and AchE in brain tissue of the mice in the model group were all significantly increased(all P<0.05),the contents of LXA4 in brain tissue were significantly decreased(all P<0.05),and the contents of α-secretase did not change significantly(all P>0.05);compared with the model group,the number of learning tests,the number of memory errors,the error rate and the content of β-secretase,γ-secretase and AchE in brain tissue were all significantly reduced(all P<0.05),the content of LXA4 in brain tissue of the high dose group of honeysuckle chlorogenic acid was significantly increased(P<0.05),and there was no significant change in the content of α-secretase in brain tissue of all groups of honeysuckle chlorogenic acid(all P>0.05).Compared with the normal group,the levels of blood glucose,TC,TG,ALT,BUN,Cr and UA in the model group and the levels of TC,TG and BUN in the low-and medium-dose groups of honeysuckle chlorogenic acid were significantly increased(all P<0.05),and the level of HDL-C in the model group and the levels of UA in the medium-and high-dose groups of honeysuckle chlorogenic acid were significantly decreased(all P<0.05);compared with the model group,the levels of blood glucose,ALT,BUN,UA in each group of honeysuckle chlorogenic acid,the levels of TC and Cr in medium and high dose groups of honeysuckle chlorogenic acid,and the level of TG in the high dose group of honeysuckle chlorogenic acid were all signifi-cantly lower(all P<0.05),while the level of HDL-C in the medium and high dose groups of honeysuckle chlorogenic acid and the level of to-tal protein in the high dose group of honeysuckle chlorogenic acid were all significantly higher(all P<0.05).[Conclusions]Chlorogenic acid from honeysuckle may improve AD induced by aluminum exposure via regulating related secretory enzymes,LXA4,and various biochemi-cal indicators.

Chlorogenic acid alleviates hypoxic-ischemic brain injury in neonatal mice

Recent studies have shown that chlorogenic acid(CGA),which is present in coffee,has protective effects on the nervous system.However,its role in neonatal hypoxic-ischemic brain injury remains unclear.In this study,we established a newborn mouse model of hypoxic-ischemic brain injury using a modified Rice-Vannucci method and performed intraperitoneal injection of CGA.We found that CGA intervention effectively reduced the volume of cerebral infarct,alleviated cerebral edema,restored brain tissue structure after injury,and promoted axon growth in injured brain tissue.Moreover,CGA pretreatment alleviated oxygen-glucose deprivation damage of primary neurons and promoted neuron survival.In addition,changes in ferroptosis-related proteins caused by hypoxic-ischemic brain injury were partially reversed by CGA.Furthermore,CGA intervention upregulated the expression of the key ferroptosis factor glutathione peroxidase 4 and its upstream glutamate/cystine antiporter related factors SLC7A11 and SLC3A2.In summary,our findings reveal that CGA alleviates hypoxic-ischemic brain injury in neonatal mice by reducing ferroptosis,providing new ideas for the treatment of neonatal hypoxic-ischemic brain injury.

Exploring the anti-aging effects of chlorogenic acid and the underlying mechanisms based on a Caenorhabditis elegans model

Objective:To explore the anti-aging effects of chlorogenic acid(CGA)and the underlying mechanisms based on a Caenorhabditis elegans(C.elegans)model.Methods:The anti-agingactivityofCGAwasstudied basedon thebodylength,exercisebehavior,lipofuscin content,antioxidative stress ability,swallowing frequency,body-bending frequency,and head-swinging ability of C.elegans.Through DAF-16 nuclear translocation and SOD-3-GFP fluorescence experiments,the effects of CGA on ROS levels,antioxidant enzyme activities,MDA content,mutant-strain lifespan,and anti-aging molecular signaling pathways were explored,as well as the underlying mechanisms.Results:CGA improved multiple indices of the nematode:body length was increased(all P<0.001),head-swing frequency and body-bending frequency were increased(all P<0.05),nematode longevity was prolonged(P=0.0021),lipofuscin deposition in nematodes was slowed down(all P<0.001),the chemotaxis index was improved(P=0.0012),ROS levels were reduced(all P<.001),and SOD activity and MDA content were reduced(SOD:P=0.0017 between the low-concentration group and the control group,P<.001 between the high-concentration and medium-concentration groups and the control group;MDA:P=0.0135 between the low-concentration group and the control group,and P<0.001 between the high-concentration and medium-concentration groups and the control group).In addition,CGA also activated the DAF-16 transcription factor,promoted DAF-16 nuclear translocation under oxidative stress conditions(both P<0.001 between the high-concentration and medium-concentration groups and the control group),and increased SOD-3 gene expression in nematodes(all P<0.001).Conclusion:CGA plays an anti-aging role in C.elegans.The underlying mechanisms include activation of the insulin/IGF-1 signaling pathway and enhancement of DAF-16 activity.This study lays a foundation for further research into the anti-aging effects of CGA.

Identification and expression analysis of chlorogenic acid biosynthesis key gene PpHCT in peach

Shikimic acid/quinic acid hydroxy cinnamyl transferase(HCT)is one of the key enzymes in the phenylpropanoid pathway.However,the role of the HCT gene in chlorogenic acid(CGA)biosynthesis in peach fruit remains unclear.For this,we identified the accumulation pattern of CGA in four peach cultivars,cloned and characterized 11 PpHCT gene members,and further analyzed the expression patterns of these PpHCT genes during fruit development.The contents of CGAs in the four peach cultivars all exhibited a trend of increasing and then decreasing during the fruit growth and development.Moreover,the contents of CGAs in the peel and flesh were tissue-specific.Gene structure analysis indicated that the PpHCT genes were highly conserved,containing two exons and one intron.The protein structure analysis demonstrated that the PpHCT proteins contained two conserved motifs(HXXXD,DFGWG)and a transferase domain(PF02458),which belonged to the BAHD acyltransferase family.The cis-acting element analysis suggested that the promoters of PpHCT genes contained many light-related,hormone-related,stress-related,tissue-specific,and circadian-related elements,and they could participate in a variety of biological processes.Phylogenetic analysis showed that the HCT proteins of peach were closely related to the HCT proteins of plum and had a close evolutionary relationship.The qRT-PCR analysis indicated that the expression levels of PpHCT1 and PpHCT2 showed an opposite trend to the accumulation of CGA,whereas the expression levels of PpHCT4,PpHCT5,PpHCT7,PpHCT8,and PpHCT11 demonstrated the same trend as CGA accumulation.It was worth noting that only PpHCT4 and PpHCT5 were highly expressed in the two high-CGA cultivars but showed low levels of expression in the two low-CGA cultivars.Therefore,it was hypothesized that these two genes might be key genes to the synthesis of CGA in peach fruit.Those findings provide a theoretical basis for further study on the biological functions of the HCT gene and help to reveal the molecular mechanism of CGA.

Modulating Effects of Chlorogenic Acid on Lipids and Glucose Metabolism and Expression of Hepatic Peroxisome Proliferator-activated Receptor-α in Golden Hamsters Fed on High Fat Diet

Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α） in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group （n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily）, and control group （n=10, given PBS i.p. at the average volume of the treatment group）. Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride （TG）, free fatty acid （FFA）, total cholesterol （TC）, low density lipoprotein cholesterol （LDL-C）, high density lipoprotein cholesterol （HDL-C）, glucose （FSG）, and insulin （FSI） were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase （HL） lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase （LPL） in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.

Effect of chlorogenic acid on antioxidant activity of Flos Lonicerae extracts

Flos Lonicerae is a medically useful traditional Chinese medicine herb. However, little is known about the antioxidant properties of Flos Lonicerae extracts. Here the antioxidant capacity of water, methanolic and ethanolic extracts prepared from Flos Lonicerae to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and reduce Fe3+ to Fe2+ is examined. Chlorogenic acid, a major component of Flos Lonicerae, is identified and further purified from 70% ethanolic extract with high performance liquid chromatography (HPLC) and its antioxidant capacity is characterized. The total phenolic compounds and chlorogenic acid con-tents in Flos Lonicerae are determined. The present results demonstrate that the Flos Lonicerae extracts exhibit antioxidant ac-tivity and chlorogenic acid is a major contributor to this activity.

Chlorogenic Acid Maintains Glucose Homeostasis through Modulating the Expression of SGLT-1,GLUT-2,and PLG in Different Intestinal Segments of Sprague-Dawley Rats Fed a High-Fat Diet

Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.

Chlorogenic acid loaded chitosan nanoparticles with sustained release property,retained antioxidant activity and enhanced bioavailability

In this study,chlorogenic acid(CGA),a phenolic compound widely distributed in fruits and vegetables,was encapsulated into chitosan nanoparticles by ionic gelation method.The particles exhibited the size and zeta potential of 210 nm and 33 mV respectively.A regular,spherical shaped distribution of nanoparticles was observed through scanning electron microscopy(SEM)and the success of entrapment was confirmed by FTIR analysis.The encapsulation efficiency of CGA was at about 59%with the loading efficiency of 5.2%.In vitro ABTS assay indicated that the radical scavenging activity of CAG was retained in the nanostructure and further,the release kinetics study revealed the burst release of 69%CGA from nanoparticles at the end of 100th hours.Pharmacokinetic analysis in rats showed a lower level of Cmax,longer Tmax,longer MRT,larger AUC0et and AUC0e∞for the CGA nanoparticles compared to free CGA.Collectively,these results suggest that the synthesised nanoparticle with sustained release property can therefore ease the fortification of food-matrices targeted for health benefits through effective delivery of CGA in body.

Comparative pharmacokinetics of chlorogenic acid after oral administration in rats

The present study was aimed at the comparison of the pharmacokinetics of pure chlorogenic acid and extract of Solanum lyratum Thunb. The animals were allocated to two groups, and were administered chlorogenic acid or extract of S. lyratum Thunb. at a dose of 50.0 mg/kg orally. Blood samples were collected up to 8 h post-dosing. Plasma chlorogenic acid analyses were performed using an HPLC method with UV detector. The pharmacokinetic parameters were evaluated using non-compartmental assessment. Significant differences existed in the two groups for AUCo-t, AUCo-∞ and CLz/F. The reliable HPLC method was successfully applied to the determination of chlorogenic acid in rat plasma at dosting of 50.0 mg/kz.

Overexpression of IbPAL1 promotes chlorogenic acid biosynthesis in sweetpotato

Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities,is distributed in all edible parts of sweetpotato.However,little is known about the specific metabolism of CGA in sweetpotato.In this study,IbPAL1,which encodes an endoplasmic reticulum-localized phenylalanine ammonia lyase(PAL),was isolated and characterized in sweetpotato.CGA accumulation was positively associated with the expression pattern of IbPAL1 in a tissue-specific manner,as further demonstrated by overexpression of IbPAL1.Overexpression of IbPAL1 promoted CGA accumulation and biosynthetic pathway genes expression in leaves,stimulated secondary xylem cell expansion in stems,and inhibited storage root formation.Our results support a potential role for IbPAL1 in sweetpotato CGA biosynthesis and establish a theoretical foundation for detailed mechanism research and nutrient improvement in sweetpotato breeding programs.

Chlorogenic acid complex(CGA7),standardized extract from green coffee beans exerts anticancer effects against cultured human colon cancer HCT-116 cells

Coffee is commonly consumed beverage in the world and it has been suggested to have beneficial effect.Chlorogenic acids(CGAs)are main ingredient of coffee beans which has been extensively used in nutraceuticals and medicine.Recently,various therapeutic effects of chlorogenic acids have been investigated.However,there are limited studies to investigate its anticancer properties.In the present study,we have used chlorogenic acid complex(CGA7)a decaffeinated water soluble green coffee bean extract to evaluate its cytotoxic effect on human and mouse cancer cell lines by using different approaches.From our results we found CGA7 treatment induces cell death in a dose and time dependent manner in different cancer cell lines.Further,CGA7 induced apoptosis was characterized by DNA fragmentation,PARP-1 cleavage,caspase-9 activation,and down regulation of Bcl-2,an anti-apoptotic protein and up regulation of pro-apoptotic protein BAX.Overall findings indicated that CGA7 complex a potent anticancer molecule found in green coffee beans could be a safe bioactive ingredient for prevention of cancer.

Determination of chlorogenic acid by flow injection irreversible biamperometry

A flow injection irreversible biamperometric method for the determination of chlorogenic acid is described. The proposed method is based on the electrochemical oxidation of chlorogenic acid at pretreated platinum electrode and the reduction of permanganate at another electrode to form an irreversible biamperometric detection system. Under the external potential difference （z^v） of 0 V, in the 0.05 mol/L sulfuric acid, chlorogenic acid can be determined over the range 0.8-120 mg/L with a sample measurement frequency of 80 samples/h. The detection limit is 0.18 mg/L. The proposed method exhibits the satisfactory reproducibility with a relative standard derivation （R.S.D.） of 2.21% for 19 successive determinations of 40 mg/L.

Determination of Chlorogenic Acid,Macranthoidin B and Dipsacoside B in Flos Lonicera by HPLC-ELSD

[Objective] A method for the determination of chlorogenic acid, macranthoidin B and dipsacoside B in Flos Lonicera by high performance liquid chromatography（HPLC） with evaporative light scattering detection（ELSD） was established.[Method] The separation was carried out using a ZORBAX SB-C18 chromatographic column（4.6 mm ×250 mm, 5 μm）, with a simple mobile phase of acetonitrile and0.1% formic acid. Evaporative light scattering detector was employed. [Result] The result showed that chlorogenic aicd, macranthoidin B and dipsacoside B showed good linearities in the ranges of 3.00-6.40, 4.24-9.33 and 0.40-2.00 μg with correlation coefficient of 0.999, 0.993 and 0.999, respectively. [Conclusion] The method has the advantages of simple operation, good accuracy, repeatability and separation effect and high specificity and is suitable for overall quality control of Flos Lonicera.

Transcriptome analysis to identify candidate genes related to chlorogenic acid biosynthesis during development of Korla fragrant pear in Xinjiang

Korla fragrant pear(KFP)with special fragrance is a unique cultivar in Xinjiang,China.In order to explore the biosynthesis molecular mechanism of chlorogenic acid(CGA)in KFP,the samples at different development periods were collected for transcriptome analysis.High performance liquid chromatography analysis showed that CGA contents of KFP at 88,118 and 163 days after full bloom were(20.96±1.84),(12.01±0.91)and(7.16±0.41)mg/100 g,respectively,and decreased with the fruit development.Pears from these typical 3 periods were selected for de novo transcriptome assemble and 68059 unigenes were assembled from 444037960 clean reads.One‘phenylpropanoid biosynthesis’pathway including 57 unigenes,11 PALs,1 PTAL,64CLs,9 C4Hs,25 HCTs and 5 C3’Hs related to CGA biosynthesis was determined.It was found that the expression levels of 11 differentially expressed genes including 1 PAL,2 C4Hs,34CLs and 5 HCTs were consistent with the change of CGA content.Quantitative polymerase chain reaction analysis further showed that 8 unigenes involved in CGA biosynthesis were consistent with the RNA-seq data.These findings will provide a comprehensive understanding and valuable information on the genetic engineering and molecular breeding in KFP.

Purification of chlorogenic acid in Flos Lonicerae with system of polar ordered resins

A system of polar ordered resins was established for purification of chlorogenic acid in Flos Lonicerae. It was composed of three reversed phase resins, AB-8, DM-130 and NKA-9, representative for their gradually increased polarity and selectivity. A method of RP-HPLC was used for determination of chlorogenic acid. And the performance of adsorption and desorption for chlorogenic acid with the system of polar ordered resins was studied. Furthermore, the effects of concentration, pH and flow rate of the adsorbate on adsorption ability were researched. It is indicated that the optimum parameters for chlorogenic acid are as follows: pH 3.5 with a flow rate of 2.5 BVh, the concentration of extract solution at 0.50, 0.40, 0.30 gL respectively for the adsorptive operation twice, and 6.93, 8.66, 10.39 molL ethanol used as gradient eluants. The purity of resulted product of chlorogenic acid arrives 70.20% with yield of 89.79%. With simple procedures, low costs and high purity product, the method of system of polar ordered resins followed by sequential reversed phase separations can be used to refine the chlorogenic acid in the extraction of Flos Lonicerae.

Differences Between the Concentrations in Rabbit Body Fluid of Berberine Hydrochloride, Chlorogenic Acid, Baicalin, and Their Minimal Inhibitory Concentrations

To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride （Ber. H）, chlorogenic acid （Chlo. A）, and baicalin （Bai）, their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations （MICs）. Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL^-1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL^-1, respectively. Their MICs to E. coli were, respectively, 1.0×10^3, 3.75 × 10^3, and 6.75 ×10^3μg mL^-1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.

Preparation of Fe_(3)O_(4)@SW-MIL-101-NH_(2) for selective preconcentration of chlorogenic acid metabolites in rat plasma,urine,and feces samples

An innovative sandwich-structural Fe-based metal-organic framework magnetic material(Fe_(3)O_(4)@SWMIL-101-NH_(2))was fabricated using a facile solvothermal method.The characteristic properties of the material were investigated by field emission scanning electron microscopy,transmission electron microscopy(TEM),energy-dispersive X-ray spectroscopy,Fourier transform infrared spectroscopy,X-ray powder diffraction,vibrating sample magnetometry,and Brunauer-Emmett-Teller measurements.Fe_(3)O_(4)@SW-MIL-101-NH_(2) is associated with advantages,such as robust magnetic properties,high specific surface area,and satisfactory storage stability,as well as good selective recognition ability for chlorogenic acid(CA)and its metabolites via chelation,hydrogen bonding,and p-interaction.The results of the static adsorption experiment indicated that Fe_(3)O_(4)@SW-MIL-101-NH_(2) possessed a high adsorption capacity toward CA and its isomers,cryptochlorogenic acid(CCA)and neochlorogenic acid(NCA),and the adsorption behaviors were fitted using the Langmuir adsorption isotherm model.Then,a strategy using magnetic solid-phase extraction(MSPE)and ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF MS/MS)was developed and successfully employed for the selective pre-concentration and rapid identification of CA metabolites in rat plasma,urine,and feces samples.This work presents a prospective strategy for the synthesis of magnetic adsorbents and the high-efficiency pretreatment of CA metabolites.