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1.
Three new dammarane triterpenoids, gardaubryones A–C ( 1 – 3 ), were isolated from the gum collected on the aerial parts of Gardenia aubryi Vieill ., together with the known compounds hydroxydammarenone II ( 4 ), ocotillone ( 5 ), cabraleone, and hollongdione. The structures of the novel compounds were established on the basis of mass spectrometry, NMR experiments, and chemical‐correlation reactions.  相似文献   

2.
Chemical investigation of the gum resin of Ferula assa-foetida L. resulted in the isolation of a new sesquiterpenoid coumarin, 7-(((E)-5-((1S,3S,6S)-3,6-dihydroxy-2,2,6-trimethylcyclohexyl)-3-methylpent-2-en-1-yl)oxy)-2H-chromen-2-one (asimafoetidnol), together with several other known compounds. The structure of asimafoetidnol was established on the basis of spectroscopic analyses. Geometry optimization of the compound has been carried out using a DFT/B3LYP/3-21G* method.  相似文献   

3.
The simultaneous analysis of aflatoxins B1, G1, B2, G2 and ochratoxin A in beer was carried out by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS). Mycotoxins were extracted, purified and concentrated from the beer sample in one step using a solid-phase extraction (SPE) cartridge that contained a polymeric sorbent. Optimization of different parameters, such as type of SPE sorbent, type and amount of wash solvent and pH of the sample, was carried out. The mobile phase consisted of a gradient of methanol + water (0.1% HCOOH) and a reversed-phase C18 column was used for the separation. The mass spectrometer used an electrospray ionization source operated in the positive mode to detect aflatoxins and in the negative mode to detect ochratoxin. UPLC/MS/MS is a rapid and sensitive technique that allows the separation of the five toxins in only 3.2 min. The limit of detection is 1 pg.  相似文献   

4.
A reliable ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in peanuts and their derivative products was developed. The sample was extracted by 84% of acetonitrile aqueous solution and the extract was purified by a reliable solid phase extraction-based clean-up method. Then, the analytes were separated on Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 μm particle size), and eluted with a mobile phase consisting of (A) water containing 0.1% formic acid and (B) acetonitrile/methanol (50/50, v/v). The separated compounds were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in positive electro-spray ionization using multiple reaction monitoring mode. The established method was extensively validated by determining the linearity (R2 ≥ 0.9990), average recovery (74.7-86.8%) and precision (relative standard deviation ≤ 10.9%). It was shown to be a suitable method for simultaneous determination of the six aflatoxins in peanuts and their derivative products. Finally, a total of 73 samples randomly collected from different areas in Zhejiang province were screened for aflatoxins with the proposed method. The results showed that 31 samples of peanut butter, 14 samples of fresh peanut and 5 samples of musty peanut were contaminated with aflatoxins. Meanwhile, this was the first report on aflatoxins M1 and M2, which were found in unprocessed peanuts and their derivative products.  相似文献   

5.
Structural and physicochemical characteristics of mesquite gum (from Prosopis velutina) were investigated using FT-IR spectroscopic, mass spectrometric and chromatographic methods. Four fractions (F-I, F-IIa, F-IIb and F-III) were isolated by hydrophobic interaction chromatography. The samples were characterized and analyzed for their monosaccharide and oligomers composition by high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). L-Arabinose (L-Ara) and D-galactose (D-Gal) were found as the main carbohydrate constituent residues in the polysaccharides from mesquite gum and their ratio (L-Ara/D-Gal) varied within the range 2.54 to 3.06 among the various fractions. Small amounts of D-glucose (D-Glc), D-mannose (D-Man) and D-xylose (D-Xyl) were also detected, particularly in Fractions IIa, IIb and III. Infrared spectroscopy identified polysaccharides and protein in all the samples. Data from mass spectrometry (MALDI-TOF MS) was consistent with the idea that the structure corresponding to the periphereal chains of Fraction I is predominantly a chain of pentoses attached to uronic acid.  相似文献   

6.
Sucralose, a persistent chlorinated substance used as sweetener, can already be found in waste water, and various countries focused on the release of sucralose into the aquatic environment. A quantitative high-performance thin-layer chromatography (HPTLC) method, which is orthogonal to existing methods, was developed to analyze sucralose in water. After sample preparation, separation of up to 17 samples was performed in parallel on a HPTLC plate silica gel 60 F(254) with a mixture of isopropyl acetate, methanol and water (15:3:1, v/v/v) within 15 min. Due to the weak native UV absorption of sucralose (≤200 nm), various post-chromatographic derivatization reactions were compared to selectively detect sucralose in effluent and surface water matrices. Thereby p-aminobenzoic acid reagent was discovered as a new derivatization reagent for sucralose. Compared to the latter and to β-naphthol, derivatization with aniline diphenylamine o-phosphoric acid reagent was slightly preferred and densitometry was performed by absorbance measurement at 400 nm. The limit of quantification (LOQ) of sucralose in drinking and surface water was calculated to be 100 ng/L for a given recovery rate of 80% and the extraction of a 0.5 L water sample. The sucralose content determined in four water samples obtained during an interlaboratory trial in 2008 was in good agreement to the mean laboratory values of that trial. According to the t-test, which compares the results with the target value, the means obtained by HPTLC were not significantly different from the respective means of six laboratories, analyzed by HPLC-MS/MS or HPLC-TOF-MS with the use of mostly isotopically labeled standards. The good accuracy and high sample throughput capacity proved HPTLC as a well suited method regarding quantification of sucralose in various aqueous matrices.  相似文献   

7.
Propolis is a honeybee product which bees produce by collecting resins from various botanical sources. The chemical composition of propolis is directly dependant on the availability of resinous plant materials in different geographic regions. This study was undertaken to evaluate the resinous plant sources used by bees to produce Mediterranean type propolis. Although this propolis type has already been the subject of numerous studies, its major botanical source had not yet been identified. In this study, using GC-MS analysis, we identify the resin of the common cypress, Cupressus_sempervirens, as the major plant source of the characteristic diterpene fingerprint profile of Mediterranean propolis.  相似文献   

8.
Effect of environmental factors and carbohydrate on gellan gum production   总被引:3,自引:0,他引:3  
Submerged culture fermentation studies were carried out in batch mode for optimizing the environmental parameters and carbon source requirement by Pseudomonas elodea for the production of gellan gum. The maximum production of gellan gum was obtained with 16-h-old culture and 8% inoculum at 30°C and pH 7.0 after 52 h of incubation (6.0 g/L). Of the various carbon sources tested, 2% sucrose, glucose, and soluble starch yielded considerably high amounts of gellan. Studies on the concentration of various carbohydrates on gellan gum production indicated that the optimum concentration of glucose and starch was 3%, whereas for sucrose it was 4%. The addition of glucose in the medium above 3% had a detrimental effect on gellan yield. The investigation of intermediate two-step addition of glucose under identical conditions of fermentation showed an enhanced production of gellan (8.12 g/L) as compared with the control (6.0 g/L). To optimize the recovery of gellan from fermented broth, different solvents were tested for precipitation of gellan gum. Among the various solvents tested, tetrahydrofuran gave better recovery of gellan (82%) as compared with the conventional solvent isopropanol (49%).  相似文献   

9.
The wood resin in Scots pine (Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 nm. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm(-1). Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at approximately 1650 cm(-1) due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin.  相似文献   

10.
TLC characterizations are among the key identity tests in most pharmacopoeial monographs. Pharmacopoeial standards are typically used by industry as a basis for meeting QC requirements and current good manufacturing practices (cGMPs). TLC is a relatively low-cost, highly versatile tool for developing specifications for raw materials, as well as for the various preparations for which pharmacopoeial standards are created. In addition to its use in the development of identity tests, TLC is a valuable tool for screening plant samples that pharmacopoeias must review in the development of monographs and botanical reference materials (BRMs). Specifically, HPTLC is the ideal TLC technique for these purposes because of its increased accuracy, reproducibility, and ability to document the results, compared with standard TLC. Because of this, HPTLC technologies are also the most appropriate TLC technique for conformity with GMPs. This article highlights the manner in which HPTLC is used by the American Herbal Pharmacopoeia (AHP) in the development of AHP monograph identity standards, the identification of adulterating species, and the development of AHP-verified BRMs.  相似文献   

11.
A robust ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for the determination of morphine‐6‐d ‐glucuronide (M6G), morphine‐3‐d ‐glucuronide (M3G) and morphine (MOR) in human plasma and urine has been developed and validated. The analytes of interest were extracted from plasma by protein precipitation. The urine sample was prepared by dilution. Both plasma and urine samples were chromatographed on an Acquity UPLC HSS T3 column using gradient elution. Detection was performed on a Xevo TQ‐S tandem mass spectrometer in multiple reaction monitoring mode using positive electrospray ionization. Matrix interferences were not observed at the retention time of the analytes and internal standard, naloxone‐D5. The lower limits of quantitation of plasma and urine were 2/0.5/0.5 and 20/4/2 ng/mL for M6G/M3G/MOR, respectively. Calibration curves were linear over the concentration ranges of 2–2000/0.5–500/0.5–500 and 20–20,000/4–4000/2–2000 ng/mL for M6G/M3G/MOR in plasma and urine samples, respectively. The precision was <7.14% and the accuracy was within 85–115%. Furthermore, stability of the analytes at various conditions, dilution integrity, extraction recovery and matrix effect were assessed. Finally, this quantitative method was successfully applied to the pharmacokinetic study of M6G injection in Chinese noncancer pain patients.  相似文献   

12.
Advancements in automated high-performance thin-layer chromatography (HPTLC) have made it feasible to assess its use for the quantitative analysis of marker compounds in botanical preparations. We report here the findings of method comparisons for the terpenelactones and flavonol aglycones by column high-performance liquid chromatography (HPLC) with evaporative light scattering and UV detection, and HPTLC with a scanning densitometer. For the HPTLC assay of terpenelactones, total bilobalide, ginkgolide A, and ginkgolide B consistently achieved <70% of the total determined using HPLC, regardless of variations to postchromatographic derivatization time and temperature. Accuracy testing showed the possibility of a matrix interference. In contrast, a good relationship (95%) was determined between HPTLC and HPLC for determination of total flavonol glycosides (calculated from combined quercetin, kaempferol, and isorhamnetin) from an acid-hydrolyzed Ginkgo biloba L. (GBE) sample. The HPTLC flavonol aglycone method also performed well in terms of accuracy (overall average of 96% recovery for the 3 aglycones) and consecutive plate repeatability (overall percent relative standard deviation of 4.4). It is demonstrated that HPTLC can be a time-saving complement to HPLC for routine analysis of the flavonol glycosides in GBE.  相似文献   

13.
There are many examples of botanical identity methodology currently in use today; all have associated levels of confidence and, hence, application for their intended purpose. This paper addresses the application of some of these methods to identify and qualify commonly traded herbs. The relevance of botanical identity and quality within the dietary supplement industry has seen a dramatic increase in the last several years, and now with the current Good Manufacturing Practices (cGMPs) recently published and the requirement for 100% identity testing, there is an increased need for reliable methods of analysis and subsequent interpretation of the results or data derived from these methods, given the diversity of samples and matrixes seen on a daily basis in a commercial setting. Example applications of methods described herein illustrate how one can confidently and effectively satisfy the 100% identity rule of the cGMPs to identify crude raw materials and their powdered or liquid extracts as well as identify a majority of such ingredients in finished products with diverse matrixes. The three techniques discussed in this paper are viewed from a qualitative perspective with primary emphasis on the application of HPTLC to a variety of complex samples with varying degrees of difficulty of analysis and interpretation. The three methods discussed are (1) HPTLC, for its fingerprint/pattern recognition capabilities as well as marker compound analysis; (2) microscopy, for identification/recognition of unique cellular, anatomic features and characteristics of the target plant or adulterants; and (3) HPLC for marker compound identification, quantitation, and/or other fingerprint qualities it may contribute to the data set. To support the applications and methods described herein, this paper presents four key approaches to assist in the interpretation of the data collected in order to correctly determine the identity of botanicals and their powdered extracts: the "marker approach," the "multicomponent-based approach", the "pattern approach," and the "multipattern approach", and how these approaches can be used with a vanguard/rearguard strategy in analytical testing as well as forming a basis for the "functional fingerprint" and the concept of phytoequivalence.  相似文献   

14.
A sensitive, selective and robust densitometric high-performance thin-layer chromatographic method was developed and validated for five marker compounds, namely betulin, lupeol, oleanolic acid, 3-acetyloleanolic acid and β-sitosterol, known for their various therapeutic activities. The marker compounds have been isolated from the stem bark of Betula utilis, well characterized by the spectral analysis, and their simultaneous quantitative determination carried out by high-performance thin-layer chromatography (HPTLC) method. The resolution of marker compounds was carried out on silica-gel 60 plates, using n-hexane:ethyl acetate (8:2 v/v) as the mobile phase. The HPTLC densitometry was performed at 500-nm wavelength after the post chromatographic derivatization with ceric ammonium sulfate reagent. The optimized method provided good linear relation (r>0.9960) for all the investigated analytes. The method is simple, and reproducible, which may be applied for quantitative analysis of the above-mentioned marker compounds.  相似文献   

15.
The association of immunoglobulin G (IgG) glycosylation changes with various human diseases and physiological conditions is well established. Since the mechanistical explanation of the regulation of IgG glycosylation and its functional role in these various states is still missing, the eyes of the biomedical community are now turned towards animal models, which enable intervention studies necessary for conclusions on causality. Mice are recognized and used as a good experimental model for human IgG glycosylation. However, smaller blood volumes, low IgG concentrations at young ages (which are most often used in mice experiments) and multiple sampling protocols during the course of longitudinal studies would profit from a robust workflow for mouse IgG glycome analysis from minute amounts of starting material, collected through a simple sampling procedure. For this purpose, we have developed a protocol for analysis of total N-glycans of IgG isolated from mouse dried blood spots (DBS), which we report here. We show that mouse DBS are a good source of material for IgG N-glycan analysis by multiplexed capillary gel electrophoresis with laser-induced fluorescence (xCGE-LIF).  相似文献   

16.
An high-performance TLC (HPTLC) method for the separation of boswellic acids, the active constituents in Boswellia serrata extract, has been developed and TLC of these compounds on silica by automated multiple development (AMD) using solvent gradients was performed. Enhancement of the separation of boswellic acids on HPTLC plates was carried out by AMD chromatography. Densitometric analysis of the developed plate was carried out to quantify the four boswellic acids. 11-Keto-beta-boswellic acid (KBA) and acetyl-11-keto-beta-boswellic acid (AKBA) were quantified by densitometric scanning of the developed plate at 254 nm. beta-Boswellic acid (BA) and acetyl-beta-boswellic acid (ABA) were quantified after derivatization with anisaldehyde sulfuric acid reagent at 560 nm. The AMD system provided a clean separation according to polarity for each of the four groups studied and good results were obtained. The proposed HPTLC method for the simultaneous quantification of the major boswellic acids BA, ABA, KBA, and AKBA was found to be simple, precise, specific, sensitive, and accurate and can be used for routine quality control and for the quantification of these compounds in plant materials. The study of market products revealed significant variations in the content of these pharmacologically active compounds in commercial samples.  相似文献   

17.
From the stems of Kadsura heteroclita, two new lignans named heteroclitins F and G were isolated and their structures were determined by various spectroscopic means including an X-ray diffraction method. Dibenzocyclooctadiene type lignans and related compounds isolated from the stems of K. heteroclita, potently inhibited the lipid peroxidation in the rat liver homogenate stimulated by Fe(2+)-ascorbic acid, CCl4-reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine 5'-diphosphate-NADPH.  相似文献   

18.
Pistacia species contain oleoresins with bioactive triterpenes. In this study triterpenes, including minor components, were identified and quantified in both neutral and acidic fraction of Pistacia lentiscus var. Chia resin, grown exclusively in Chios island (Greece), collected traditionally, as well as by the use of stimulating agents (liquid collection). It was proved that these two resin samples were composed of several different minor triterpenes. In the traditional collection of the resin, 36 triterpenes were identified, 23 of which are new minor compounds (five in the acidic and eighteen in the neutral fraction). In the liquid collection resin eight compounds were identified in the acidic and 11 in the neutral fraction, while seven compounds were not contained in resin traditionally collected. The main triterpenes in both resin samples collected traditionally and by use of stimulating agents were in the following order: isomasticadienonic acid (24 and 22.5% w/w of triterpenic fraction respectively), masticadienonic acid (9.3 and 14.7% w/w of triterpenic fraction) and 28-norolean-17-en-3-one (19 and 36% w/w of triterpenic fraction respectively). The aim of this study was to compare the qualitative and quantitative composition of triterpenes in the resin samples collected using the traditional and new liquid techniques, and examine whether the collection technique influences the contained triterpenes in P. lentiscus var. Chia resin samples. Finally, since there is confusion on interpreting mass spectra of triterpenes we present an analytical review on the base peaks, main fragments and fragmentation mechanism/pattern of several skeleton penta- and tetra- cyclic triterpenes reported in P. lentiscus resin. Also, a biosynthetic route for triterpene skeletons contained in P. lentiscus resin was approached.  相似文献   

19.
Luo  Na  Wang  Xue  Huang  Li-Jia  Mi  Qi-Li  Zeng  Wan-Li  Xiang  Hai-Ying  Li  Jing  Liu  Xin  Hu  Qiu-Fen  Guo  Ya-Dong  Yang  Guang-Yu  Deng  Liang  Gao  Qian 《Chemistry of Natural Compounds》2021,57(5):840-843
Chemistry of Natural Compounds - Eight phenolic compounds (1–8), including two new compounds (1 and 2), were isolated from the twigs of Gardenia jasminoides. Their structures were determined...  相似文献   

20.
In this study, the synthesis, characterization, and properties of a short oil length chain–stopped(rapid) alkyd resin is investigated. Gum rosin modified alkyd resin (RA-GR) was prepared using soybean oil, phthalic anhydride, glycerin and gum rosin acid. An alkyd modified with benzoic acid (RA-BA) was also prepared for comparison. FTIR analyses and GPC measurements of the alkyds were used for characterization. Other properties such as the viscosity, acid value, and solid content of the final resins were determined. Separately, the synthesized resins were used in paint formulations without any changes in other parameters such as filler, airdrying agents, solvents, etc. Paints were applied to metal and glass surfaces and the effect of gum rosin was investigated by looking at touch and hard drying times, adhesion to metals and gloss changes. Compared to the benzoic acid modified resin (RA-BA), gum rosin modified resin (RA-GR) exhibited remarkable positive effects on the paint with a better adhesion to the metals, and short drying times without any loses in the glosses.  相似文献   

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