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Hollow fiber liquid phase microextraction with in situ derivatization for the determination of trace amounts of metformin hydrochloride (anti-diabetic drug) in biological fluids

Ben-Hander GM, Makahleh A, Saad B, Saleh MI

J Chromatogr B Analyt Technol Biomed Life Sci, 2013 Dec 15;941:123-30.
PMID: 24200841 DOI: 10.1016/j.jchromb.2013.10.007

A three phase hollow fiber liquid-phase microextraction with in situ derivatization (in situ HF-LPME) followed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV) method was developed for the trace determination of metformin hydrochloride (MH) in biological fluids. A new derivatization agent pentafluorobenzoyl chloride (PFBC) was used. Several parameters that affect the derivatization and extraction efficiency were studied and optimized (i.e., type of organic solvent, volume of NaOH (4M) and derivatization agent in the donor phase, acceptor phase (HCl) concentration, stirring speed, temperature, time and salt addition). Under the optimum conditions (organic solvent, dihexyl ether; volume of NaOH (4M) and derivatization agent (10mg PFBC in 1mL acetonitrile) in the donor phase, 600 and100μL, respectively; acceptor phase, 100mM HCl (10μL); stirring speed, 300rpm; extraction time, 30min; derivatization temperature, 70°C; without addition of salt) an enrichment factor of 210-fold was achieved. Good linearity was observed over the range of 1-1000ngmL(-1) (r(2)=0.9998). The limits of detection and quantitation were 0.56 and 1.68ngmL(-1), respectively. The proposed method has been applied for the determination of MH in biological fluids (plasma and urine) and water samples. Prior to the microextraction treatment of plasma samples, deproteinization step using acetonitrile was conducted. The proposed method is simple, rapid, sensitive and suitable for the determination of MH in a variety of samples.

Matched MeSH terms: Chromatography, High Pressure Liquid
Control of Basal Stem Rot Disease in Oil Palm by Supplementation of Calcium, Copper, and Salicylic Acid

Bivi MS, Paiko AS, Khairulmazmi A, Akhtar MS, Idris AS

Plant Pathol J, 2016 Oct;32(5):396-406.
PMID: 27721689

Continuous supplementation of mineral nutrients and salicylic acid (SA) as foliar application could improve efficacy in controlling basal stem rot (BSR) disease in oil palm seedling. It is revealed from the results that the highest disease severity index (58.3%) was recorded in T8 treatments at 9 months after inoculation. The best disease control was achieved by T7 treatments (calcium/copper/SA [Ca/Cu/SA]) (5.0%) followed by T1 (5.5%), T5 (5.8%), T3 (8.3%), T6 (8.3%), T4 (13.3%), and T2 (15.8%) treatments. Continuous supplementation of Ca/Cu/SA was found to be the most effective in controlling the disease and the high performance liquid chromatography results showed the detection of ergosterol at very low concentration in the treated samples. Moreover, the transmission electron microscopy analysis results clearly indicated that T7 treatment was also enhancing lignification, which was responsible for the thickness of the secondary cell walls and middle lamella compared to untreated samples. It was therefore, concluded that continuous supplementation of minerals nutrients and SA could effectively suppress disease severity by reducing ergosterol activity and also improve the process of lignification in the treated plants. Furthermore, this treatment also managed to delay the onset of BSR symptoms and promote the growth of the seedlings and eventually suppress the BSR disease.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Comparative Investigation of Chemical Constituents of Kernels, Leaves, Husk, and Bark of Juglans regia L., Using HPLC-DAD-ESI-MS/MS Analysis and Evaluation of Their Antioxidant, Antidiabetic, and Anti-Inflammatory Activities

Bourais I, Elmarrkechy S, Taha D, Badaoui B, Mourabit Y, Salhi N, et al.

Molecules, 2022 Dec 16;27(24).
PMID: 36558122 DOI: 10.3390/molecules27248989

Leaves, husk, kernels, and bark methanolic extracts of Juglans regia L. were tested for their in vitro antidiabetic, anti-inflammatory, and antioxidant activities. For these purposes, α-amylase and α-glucosidase were used as the main enzymes to evaluate antidiabetic activities. Moreover, lipoxidase and tyrosinase activities were tested to estimate anti-inflammatory properties. Antioxidant properties of Juglans regia L., extracts were determined using three different assays. Leaves extract has an important radical scavenging activity and a-amylase inhibition. Similarly, husk extracts showed high total phenolic content (306.36 ± 4.74 mg gallic acid equivalent/g dry extract) with an important α-amylase inhibition (IC50 = 75.42 ± 0.99 µg/mL). Kernels exhibit significant tyrosinase (IC50 = 51.38 ± 0.81 µg/mL) correlated with antioxidant activities (p < 0.05). Husk and bark extracts also showed strong anti-lipoxidase activities with IC50 equal to 29.48 ± 0.28 and 28.58 ± 0.35 µg/mL, respectively. HPLC-DAD-ESI-MS/MS analysis highlights the phenolic profile of methanolic extracts of Juglans regia L. plant parts. The identified polyphenols were known for their antioxidant, antidiabetic (dicaffeoyl-quinic acid glycoside in kernels), and anti-inflammatory (3,4-dihydroxybenzoic acid in leaves) activities. Further investigations are needed to determine molecular mechanisms involved in these effects as well as to study the properties of the main identified compounds.

Matched MeSH terms: Chromatography, High Pressure Liquid
Bioequivalence assessment of two enteric-coated aspirin brands, Nu-Seals and Loprin, after a single oral dose of 150 mg in healthy male adults

Bukhari NI, Zafar A, Shamsi Wu, Bashir MA, Mirza AA

Therapie, 2005 Mar-Apr;60(2):167-73.
PMID: 15969319

AIM: The bioequivalence of aspirin from two enteric-coated brands, Nu-seals and Loprin, identified as the reference (R) and test (T) products, respectively, was assessed.

METHODS: A two-period randomised crossover design with a washout interval of 15 days was used in this study. The study results were determined in 16 healthy volunteers, all males with ages ranging from 19-28 (23.33 +/- 3.74) years and bodyweights of 52-92 (65.89 +/- 11.39) kg. After oral ingestion of 150mg of the either brand with 200 mL of water, serial blood samples were obtained over a period of 24 hours. Plasma, harvested from blood was analysed for the concentration of salicylic acid, a deacetylated metabolite of aspirin, by a validated high performance liquid chromatography (HPLC) method. Pharmacokinetic parameters were determined for both formulations by an interactive computer-assisted PK II procedure. A general linear model for repeated measures and 90% confidence intervals (CI) was employed to assess the sequence of treatment effects and to exclude differences between the parameters due to the product and period of administration, respectively.

RESULTS: The observed 90% CI ratios (Loprin/Nu-seals) for peak concentration, time to reach the peak and area under the plasma-concentration time curve from zero to infinity of 1.03,1.08; 1.04,1.05 and 1.01,1.15, respectively, were within the bioequivalence range (0.80,1.25) stipulated by the US Food and Drug Administration.

CONCLUSION: On the basis of the findings, the test (Loprin) and reference drug (Nu-seals) were deemed bioequivalent.

Matched MeSH terms: Chromatography, High Pressure Liquid
Determination of the Leaching Potential and Residues Activity of Imidazolinone Herbicide in Clearfield Rice Soil Using High-Performance Liquid Chromatography

Bzour M, Zuki FM, Mispan MS, Jodeh S, Abdel-Latif M

Bull Environ Contam Toxicol, 2019 Aug;103(2):348-353.
PMID: 31069403 DOI: 10.1007/s00128-019-02625-x

The residual activity of herbicides may be detrimental to the environment, requiring analysis of the persistent residues in the soil and water. A field study was conducted to measure the residues of Imidazolinone (IMI) in three Clearfield® rice field soils at three different locations in Malaysia. The analyses of IMI in the soil samples were carried out using a high-performance liquid chromatography (HPLC). These herbicides are widely used; however, few studies have been conducted on both residues, especially in the context of Malaysian soil. Residues of imazapic and imazapyr were found to fall within 0.03-0.58 µg/mL and 0.03-1.96 µg/mL, respectively, in three locations. IMI herbicides are persistent in the soil, and their residues remain for up to 85 days after application. A pre-harvest study was suggested for these herbicides on water, which will provide a clearer indicator on the use of IMI in Clearfield® rice fields.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods
Evidence of okadaic acid production in a cultured strain of the marine dinoflagellate Prorocentrum rhathymum from Malaysia

Caillaud A, de la Iglesia P, Campàs M, Elandaloussi L, Fernández M, Mohammad-Noor N, et al.

Toxicon, 2010 Feb-Mar;55(2-3):633-7.
PMID: 19631680 DOI: 10.1016/j.toxicon.2009.07.016

Protein phosphatase inhibition assay (PPIA), Neuroblastoma cell-based assay (Neuro-2a CBA) and LC-MS/MS analysis revealed for the first time the production of okadaic acid (OA) by a Prorocentrum rhathymum strain. Low amounts of OA were detected by LC-MS/MS analysis. Inhibition of PP2A activity and a weak toxicity to the Neuro-2a CBA were also observed.

Matched MeSH terms: Chromatography, High Pressure Liquid
HPLC-Based Qualitative and Quantitative Analyses of Alkaloids in Chewable Areca Products from Different Geographic Regions

Cao M, Liu Y, Yuan H, Qiu Y, Xie Q, Yi P, et al.

J AOAC Int, 2020 Sep 01;103(5):1400-1405.
PMID: 33241395 DOI: 10.1093/jaoacint/qsaa048

BACKGROUND: Chewable areca products are popular in Asian countries, including India, Pakistan, Malaysia, and China. The major alkaloids present in areca products are guvacine, arecaidine, guvacoline, and arecoline which cause carcinogenicity and addiction.
OBJECTIVE: The objective of this study was the quantitative analysis of the alkaloid content of areca chewable products from different countries and regions using HPLC-UV, as well as the benefit of their safety evaluation products.
METHOD: An HPLC-UV method was established for qualitative and quantitative analyses of 65 batches of areca chewable products from different countries and regions. Additionally, similarity evaluation of chromatographic fingerprints was applied for data analysis.
RESULTS: These results reveal a significant variation in the levels of areca alkaloids among tested products, specifically guvacoline (0.060-1.216 mg/g), arecoline (0.376-3.592 mg/g), guvacine (0.028-1.184 mg/g), and arecaidine (0.184-1.291 mg/g). There were significant differences in the alkaloid content of areca chewable products from different producing areas.
CONCLUSIONS: The method will be useful in the safety evaluation of different areca chewable products.
HIGHLIGHTS: The established HPLC-UV method can be adopted for safety evaluation of areca chewable products from different countries and regions due to its general applicability.

Matched MeSH terms: Chromatography, High Pressure Liquid
Minor methylated pyranoamentoflavones from Calophyllum venulosum

Cao SG, Sim KY, Goh SH

Nat Prod Lett, 2001;15(5):291-7.
PMID: 11841112

Two new biflavonoids, pyranoamentoflavone 7-methyl ether (1) and pyranoamentoflavone 4'-methyl ether (2), have been isolated from the leaves of Calophyllum venulosum. The structures of these two new compounds were elucidated by spectroscopic data.

Matched MeSH terms: Chromatography, High Pressure Liquid
Modeling and prediction of extraction profile for microwave-assisted extraction based on absorbed microwave energy

Chan CH, Yusoff R, Ngoh GC

Food Chem, 2013 Sep 1;140(1-2):147-53.
PMID: 23578626 DOI: 10.1016/j.foodchem.2013.02.057

A modeling technique based on absorbed microwave energy was proposed to model microwave-assisted extraction (MAE) of antioxidant compounds from cocoa (Theobroma cacao L.) leaves. By adapting suitable extraction model at the basis of microwave energy absorbed during extraction, the model can be developed to predict extraction profile of MAE at various microwave irradiation power (100-600 W) and solvent loading (100-300 ml). Verification with experimental data confirmed that the prediction was accurate in capturing the extraction profile of MAE (R-square value greater than 0.87). Besides, the predicted yields from the model showed good agreement with the experimental results with less than 10% deviation observed. Furthermore, suitable extraction times to ensure high extraction yield at various MAE conditions can be estimated based on absorbed microwave energy. The estimation is feasible as more than 85% of active compounds can be extracted when compared with the conventional extraction technique.

Matched MeSH terms: Chromatography, High Pressure Liquid
High performance liquid chromatography in phytochemical analysis of Eurycoma longifolia

Chan KL, Choo CY, Morita H, Itokawa H

Planta Med, 1998 Dec;64(8):741-5.
PMID: 17253320 DOI: 10.1055/s-2006-957570

An analytical method using HPLC with UV detection was developed to investigate the quassinoid content of Eurycoma longifolia Jack (Simaroubaceae) collected from various sources. Eurycomanone (1), longilactone (2), 14,15beta-dihydroxyklaineanone (3), 15beta-acetyl-14-hydroxyklaineanone (4), 6alpha-hydroxyeurycomalactone (5), and eurycomalactone (7) were isolated as reference standards and together with the synthesized 1beta,12alpha,15beta-triacetyleurycomanone (6, internal standard), were identified by NMR, MS, UV and IR spectroscopies. Their coefficient of variation values for 0.50-35 microg ml(-1) concentrations of quassinoids and their retention times measured within- and between-day were small. The recoveries of the spiked quassinoids in E. longifolia samples and their detection limits at 8.5 times signal to noise ratio were 99.75-109.13% and 0.01 microg ml(-1), respectively. From the root samples analysed, 1 had the highest concentration, being about 16.8-39.6 fold higher than the other quassinoids 2, 3, 5, 7 but 145.3 fold higher than 4 which showed the lowest concentration.

Matched MeSH terms: Chromatography, High Pressure Liquid
A high-performance liquid chromatography analysis of plasma artemisinin using a glassy carbon electrode for reductive electrochemical detection

Chan KL, Yuen KH, Jinadasa S, Peh KK, Toh WT

Planta Med, 1997 Feb;63(1):66-9.
PMID: 9063097

A high-performance liquid chromatography assay equipped with a glassy carbon electrode for electrochemical detection (HPLC-ECD) was developed at reductive mode for the analysis of artemisinin, the antimalarial drug from Artemisia annua (Asteraceae) in human plasma. This method was selective, sensitive, and produced satisfactory recovery, precision, and accuracy. Analysis of plasma samples from 8 male volunteers given 10 mg kg-1 of artemisinin orally as an aqueous suspension showed a mean peak plasma concentration (Cmax) of 580.89 ng ml-1 +/- 88.64 SD at 2.5 h +/- 0.5 SD after dosing, and the mean area under the plasma concentration-time curve (AUC0-infinity) was 2227.57 ng h ml-1 +/- 677.22 SD. In addition, the elimination rate constant (Ke), elimination half-life (t1/2), and apparent volume of distribution (Vd) were calculated to be 0.2971 h-1 +/- 0.0644 SD, 2.42 h +/- 0.46 SD, and 16.26 l kg-1 +/- 3.44 SD, respectively.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Fulltext UHPLC-ESI-Orbitrap-MS Analysis of Biologically Active Extracts from Gynura procumbens (Lour.) Merr. and Cleome gynandra L. Leaves

Chandradevan M, Simoh S, Mediani A, Ismail NH, Ismail IS, Abas F

Evid Based Complement Alternat Med, 2020;2020:3238561.
PMID: 32047522 DOI: 10.1155/2020/3238561

This study aimed to determine the total phenolic content, DPPH scavenging, α-glucosidase, and nitric oxide (NO) inhibition of Gynura procumbens and Cleome gynandra extracts obtained with five different ethanolic concentrations. The findings showed that the 100% ethanolic extract of G. procumbens had the highest phenolic content and the lowest IC50 values for DPPH scavenging and NO inhibition activity compared to the properties of the other extracts. For C. gynandra, the 20% and 100% ethanolic extracts had comparably high total phenolic contents, and the latter possessed the lowest IC50 value in the NO inhibition assay. In addition, the 20% ethanolic extract of C. gynandra had the lowest IC50 value in the DPPH scavenging assay. However, none of the extracts from either herb had the ability to inhibit α-glucosidase enzyme. Pearson correlation analysis indicated a strong relationship between the phenolic content and DPPH scavenging activity in both herb extracts. A moderately strong relationship was also observed between the phenolic content and NO inhibition in G. procumbens extracts and not in C. gynandra extracts. The UHPLC-ESI-Orbitrap-MS revealed major phenolics from the groups of hydroxycinnamic acids, hydroxybenzoic acids, and flavonoid derivatives from both herbs, which could be the key contributors to their bioactivities. Among the identified metabolites, 24 metabolites were tentatively assigned for the first time from both species of studied herbs. These two herbs could be recommended as prospective natural products with valuable medicinal properties.

Matched MeSH terms: Chromatography, High Pressure Liquid
Biowaiver monograph for immediate-release solid oral dosage forms: bisoprolol fumarate

Charoo NA, Shamsher AA, Lian LY, Abrahamsson B, Cristofoletti R, Groot DW, et al.

J Pharm Sci, 2014 Feb;103(2):378-91.
PMID: 24382794 DOI: 10.1002/jps.23817

Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release (IR) solid oral dosage forms containing bisoprolol as the sole active pharmaceutical ingredient (API) are reviewed. Bisoprolol is classified as a Class I API according to the current Biopharmaceutics Classification System (BCS). In addition to the BCS class, its therapeutic index, pharmacokinetic properties, data related to the possibility of excipient interactions, and reported BE/bioavailability problems are taken into consideration. Qualitative compositions of IR tablet dosage forms of bisoprolol with a marketing authorization (MA) in ICH (International Conference on Harmonisation) countries are tabulated. It was inferred that these tablets had been demonstrated to be bioequivalent to the innovator product. No reports of failure to meet BE standards have been made in the open literature. On the basis of all these pieces of evidence, a biowaiver can currently be recommended for bisoprolol fumarate IR dosage forms if (1) the test product contains only excipients that are well known, and used in normal amounts, for example, those tabulated for products with MA in ICH countries and (2) both the test and comparator dosage form are very rapidly dissolving, or, rapidly dissolving with similarity of the dissolution profiles demonstrated at pH 1.2, 4.5, and 6.8.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Validation of a HPLC/FLD Method for Quantification of Tocotrienols in Human Plasma

Che HL, Tan DM, Meganathan P, Gan YL, Abdul Razak G, Fu JY

Int J Anal Chem, 2015;2015:357609.
PMID: 26604927 DOI: 10.1155/2015/357609

Quantification of tocotrienols in human plasma is critical when the attention towards tocotrienols on its distinctive properties is arising. We aim to develop a simple and practical normal-phase high performance liquid chromatography method to quantify the amount of four tocotrienol homologues in human plasma. Using both the external and internal standards, tocotrienol homologues were quantified via a normal-phase high performance liquid chromatography with fluorescence detector maintained at the excitation wavelength of 295 nm and the emission wavelength of 325 nm. The four tocotrienol homologues were well separated within 30 minutes. A large interindividual variation between subjects was observed as the absorption of tocotrienols is dependent on food matrix and gut lipolysis. The accuracies of lower and upper limit of quantification ranged between 92% and 109% for intraday assays and 90% and 112% for interday assays. This method was successfully applied to quantify the total amount of four tocotrienol homologues in human plasma.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Enhancement of a protocol purifying T1 lipase through molecular approach

Che Hussian CHA, Raja Abd Rahman RNZ, Thean Chor AL, Salleh AB, Mohamad Ali MS

PeerJ, 2018;6:e5833.
PMID: 30479887 DOI: 10.7717/peerj.5833

T1 Lipase is a thermostable secretary protein of Geobacillus zalihae strain previously expressed in a prokaryotic system and purified using three-step purification: affinity 1, affinity 2, and ion exchange chromatography (IEX). This approach is time consuming and offers low purity and recovery yield. In order to enhance the purification strategy of T1 lipase, affinity 2 was removed so that after affinity 1, the cleaved Glutathione S-transferase (GST) and matured T1 lipase could be directly separated through IEX. Therefore, a rational design of GST isoelectric point (pI) was implemented by prediction using ExPASy software in order to enhance the differences of pI values between GST and matured T1 lipase. Site-directed mutagenesis at two locations flanking the downstream region of GST sequences (H215R and G213R) was successfully performed. Double point mutations changed the charge on GST from 6.10 to 6.53. The purified lipase from the new construct GST tag mutant-T1 was successfully purified using two steps of purification with 6,849 U/mg of lipase specific activity, 33% yield, and a 44-fold increase in purification. Hence, the increment of the pI values in the GST tag fusion T1 lipase resulted in a successful direct separation through IEX and lead to successful purification.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext UHPLC-UV/PDA Method Validation for Simultaneous Quantification of Luteolin and Apigenin Derivatives from Elaeis guineensis Leaf Extracts: An Application for Antioxidant Herbal Preparation

Che Zain MS, Osman MF, Lee SY, Shaari K

Molecules, 2021 Feb 19;26(4).
PMID: 33669484 DOI: 10.3390/molecules26041084

Luteolin and apigenin derivatives present in oil palm (Elaeis guineensis) leaves (OPL) are reported to possess excellent antioxidant properties relating to numerous health benefits. To meet the global demand for flavonoids, OPL, which is plentifully generated as an agricultural by-product from oil palm plantations, can be further exploited as a new source of natural antioxidant compounds. However, to produce a standardized herbal preparation, validation of the quantification method for these compounds is required. Therefore, in this investigation, we developed and validated an improved and rapid analytical method, ultra-high-performance liquid chromatography equipped with ultraviolet/photodiode array (UHPLC-UV/PDA) for the quantification of 12 luteolin and apigenin derivatives, particularly focusing on flavonoid isomeric pairs: orientin/isoorientin and vitexin/isovitexin, present in various OPL extracts. Several validation parameters were assessed, resulting in the UHPLC-UV/PDA technique offering good specificity, linearity, accuracy, precision, and robustness, where the values were within acceptable limits. Subsequently, the validated method was employed to quantify luteolin and apigenin derivatives from OPL subjected to different drying treatments and extraction with various solvent systems, giving total luteolin (TLC) and apigenin content (TAC) in the range of 2.04-56.30 and 1.84-160.38 µg/mg extract, respectively. Additionally, partial least square (PLS) analysis disclosed the combination of freeze dry-aqueous methanol yielded OPL extracts with high TLC and TAC, which are strongly correlated with antioxidant activity. Therefore, we provide the first validation report of the UHPLC-UV/PDA method for quantification of luteolin and apigenin derivatives present in various OPL extracts, suggesting that this approach could be employed in standardized herbal preparations by adopting orientin, isoorientin, vitexin, and isovitexin as chemical markers.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Improved high-performance liquid chromatographic analysis of terazosin in human plasma

Cheah PY, Yuen KH, Liong ML

J Chromatogr B Biomed Sci Appl, 2000 Aug 18;745(2):439-43.
PMID: 11043762

A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) method was developed for the determination of terazosin in human plasma. The method involves a one-step single solvent extraction procedure using dichloromethane with a 0.25 ml plasma sample. Recovery values were all greater than 90% over the concentration range 0.25-100 ng/ml. Terazosin was found to adsorb to glass or plastic tubes, but this could be circumvented by using disposable plastic tubes. Also, rinsing the injector port with methanol after each injection helped to prevent any carry-over effect. The internal standard, prazosin, did not exhibit this problem. The method has a quantification limit of 0.25 ng/ml. The within- and between-day coefficient of variation and accuracy values were all less than 7% over the concentration range 0.25-100 ng/ml and hence the method is suitable for use in pharmacokinetic studies of terazosin.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Fulltext Analysis of flavone C-glycosides in the leaves of Clinacanthus nutans (Burm. f.) Lindau by HPTLC and HPLC-UV/DAD

Chelyn JL, Omar MH, Mohd Yousof NS, Ranggasamy R, Wasiman MI, Ismail Z

ScientificWorldJournal, 2014;2014:724267.
PMID: 25405231 DOI: 10.1155/2014/724267

Clinacanthus nutans (family Acanthaceae) has been used for the treatment of inflammation and herpes viral infection. Currently, there has not been any report on the qualitative and quantitative determination of the chemical markers in the leaves of C. nutans. The C-glycosidic flavones such as shaftoside, isoorientin, orientin, isovitexin, and vitexin have been found to be major flavonoids in the leaves of this plant. Therefore, we had developed a two-step method using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC) for the rapid identification and quantification of the flavones C-glycosides in C. nutans leaves. The TLC separation of the chemical markers was achieved on silica gel 60 plate using ethyl acetate : formic acid : acetic acid : water (100 : 11 : 11 : 27 v/v/v/v) as the mobile phase. HPLC method was optimized and validated for the quantification of shaftoside, orientin, isovitexin, and vitexin and was shown to be linear in concentration range tested (0.4-200 μg/mL, r(2) ≥ 0.996), precise (RSD ≤ 4.54%), and accurate (95-105%). The concentration of shaftoside, orientin, vitexin, and isovitexin in C. nutans leave samples was 2.55-17.43, 0.00-0.86, 0.00-2.01, and 0.00-0.91 mmol/g, respectively.

Matched MeSH terms: Chromatography, High Pressure Liquid
Adenylosuccinate lyase deficiency in a Malaysian patient, with novel adenylosuccinate lyase gene mutations

Chen BC, McGown IN, Thong MK, Pitt J, Yunus ZM, Khoo TB, et al.

J Inherit Metab Dis, 2010 Dec;33 Suppl 3:S159-62.
PMID: 20177786 DOI: 10.1007/s10545-010-9056-z

Most cases of adenylosuccinate lyase (ADSL OMIM 103050) deficiency reported to date are confined to the various European ethnic groups. We report on the first Malaysian case of ADSL deficiency, which appears also to be the first reported Asian case. The case was diagnosed among a cohort of 450 patients with clinical features of psychomotor retardation, global developmental delay, seizures, microcephaly and/or autistic behaviour. The patient presented with frequent convulsions and severe myoclonic jerk within the first few days of life and severe psychomotor retardation. The high performance liquid chromatography (HPLC) profile of the urine revealed the characteristic biochemical markers of succinyladenosine (S-Ado) and succinyl-aminoimidazole carboximide riboside (SAICAr). The urinary S-Ado/SAICAr ratio was found to be 1.02 (type I ADSL deficiency). The patient was compound heterozygous for two novel mutations, c.445C > G (p.R149G) and c.774_778insG (p.A260GfsX24).

Matched MeSH terms: Chromatography, High Pressure Liquid
Characterization and determination of casein glycomacropeptide in dairy products by UHPLC-MS/MS based on its characteristic peptide

Chen Q, Lai S, Dong L, Liu Y, Pan D, Wu Z, et al.

Food Chem, 2024 Jan 01;430:137049.
PMID: 37544157 DOI: 10.1016/j.foodchem.2023.137049

The ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS) method was built to quantify the casein glycomacropeptide (CGMP) in bovine dairy products accurately based on targeted proteomics. Qualitative analysis of theoretical peptides was carried out using high-resolution mass spectrometry (HRMS) and protein software. Isotope-labeled characteristic peptides were acquired via the labeled amino acid condensation method to correct the matrix effects. Peptide MAIPPK was the representative characteristic peptide for distinguishing the CGMP from κ-casein through trypsin digestion. After optimizing the pre-treatment conditions, the final 8% oxidant concentration was selected and the 10% formic acid concentration with 2.5 h oxidation time. Moreover, the results of methodological verification showed that the recovery rate was 103.7%, meanwhile the precision of inter-day and intra-day was less than 5%. In conclusion, the research demonstrated the characteristic peptide MAIPPK could quantitatively applied to detect CGMP in dairy products.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods

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