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Agnellini D, Pace M, Cinquanta S, Gardana C, Pietta PG, Mauri PL. Characteristics of Bioreactors Made with Urease and Nad Glycohydrolase Reversibly Bound to Immobilized Antibodies. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429209065246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Dario Agnellini
- Dipartimento di Scienze e Tecnologie Biomediche -Sez. Chimica Organica, University of Milano, Via G. Celoria, 2-20133, Milano, Italy
| | - Mario Pace
- Dipartimento di Scienze e Tecnologie Biomediche -Sez. Chimica Organica, University of Milano, Via G. Celoria, 2-20133, Milano, Italy
| | - Sergio Cinquanta
- Institute di Patologia Vegetale, University of Milano, via G. Celoria, 2-20133, Milano, Italy
| | - Claudio Gardana
- Dipartimento di Scienze e Tecnologie Biomediche -Sez. Chimica Organica, University of Milano, Via G. Celoria, 2-20133, Milano, Italy
| | - Pier Giorgio Pietta
- Dipartimento di Scienze e Tecnologie Biomediche -Sez. Chimica Organica, University of Milano, Via G. Celoria, 2-20133, Milano, Italy
| | - Pier Luigi Mauri
- Dipartimento di Scienze e Tecnologie Biomediche -Sez. Chimica Organica, University of Milano, Via G. Celoria, 2-20133, Milano, Italy
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Minoggio M, Bramati L, Simonetti P, Gardana C, Iemoli L, Santangelo E, Mauri PL, Spigno P, Soressi GP, Pietta PG. Polyphenol pattern and antioxidant activity of different tomato lines and cultivars. Ann Nutr Metab 2003; 47:64-9. [PMID: 12652057 DOI: 10.1159/000069277] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2002] [Accepted: 07/25/2002] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Besides antioxidant vitamins and minerals, fruits and vegetables contain flavonoids and related phenolics. The biological activities of these polyphenols have become well known in recent years evidencing their beneficial effects on human health. In this context, the characterization of the flavonoids present in tomatoes is of great interest. Thus the polyphenol pattern (including flavonols, flavanones and cinnamate derivatives), lycopene and beta-carotene concentrations and the total antioxidant activity (TAA) of the phenolic fraction from different tomato lines and cultivars have been determined. METHODS The characterization was obtained by means of spectrophotometry and HPLC analyses. RESULTS Mean values for single flavonoids were 0.68 +/- 0.16 for naringenin, 0.74 +/- 0.12 for rutin and 0.32 +/- 0.06 for a rutin-pentoside. Mean total polyphenol content was 13.15 +/- 1.15 mg/100 g and mean TAA value was 1.3 +/- 0.10 mmol/g. The obtained TAA values resulted in good accordance with the total polyphenol content (R(2) = 0.7928). The main phenolic acids were chlorogenic (mean +/- SE 0.20 +/- 0.03) and caffeic acid (mean +/- SE 0.03 +/- 0.01). Mean levels of lycopene and beta-carotene were 5.38 +/- 0.90 and 1.18 +/- 0.40 mg/100 g, respectively. CONCLUSIONS Almost all the lines characterised by low carotenoid content produce high levels of polyphenols, and consequently have the most powerful antioxidant potential.
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Affiliation(s)
- M Minoggio
- Istituto Tecnologie Biomediche - CNR, Segrate/Milan, Italy
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Abstract
8-Hydroxy-2'-deoxyguanosine (8OHdG) is regarded as an important biomarker of oxidative DNA damage and it may be estimated by using different techniques in various biological matrices, most notably DNA and urine. In the case of DNA, artifactual oxidation may take place during the isolation of DNA, its hydrolysis and possible derivatization (as for GC-MS), invalidating the measurement of 8OHdG. Therefore, the direct analysis of 8OHdG excreted into urine was preferred. Interferences from the urine matrix were excluded by applying LC-APCI-MS/MS in the multiple reaction monitoring (MRM) mode. The abundant fragment ion at m/z 168 arising from 8OHdG was monitored in the urine sample of volunteers supplemented with tomato concentrate for different times. The procedure allowed the detection of levels of 8OHdG as low as 1 ng/ml in urine sample.
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Affiliation(s)
- P G Pietta
- CNR, Istituto di Tecnologie Biomediche, Via F.lli Cervi 93, 20090 Segrate, Milano, Italy.
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Mauri PL, Basilico F, Pietta PG, Pasini E, Monti D, Sauerwein W. New approach for the detection of BSH and its metabolites using capillary electrophoresis and electrospray ionization mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 788:9-16. [PMID: 12668066 DOI: 10.1016/s1570-0232(02)01006-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Boron neutron capture therapy is a promising binary treatment for cancer. It is based on the nuclear fission that occurs when non-radioactive 10B absorbs thermal neutrons. One of the two boron compounds currently used in clinical trials for this therapy is BSH. To ensure differentiated retention in the tumour versus normal tissue prior to treatment, routine analytical methods to determine pharmacokinetics must be available. For this purpose we have developed a new, easy and time saving approach, in which the separation of boron derivatives is performed by means of capillary electrophoresis (CE). The CE method allows analyses to be performed in short times (less than 18 min), sensitively (LOD 8 pg loaded on the capillary) quantitatively (LOQ 5 microg/ml) and with a high efficiency of separation. Moreover it is simpler than HPLC and more reproducible (intra- and inter-day values were +/-1% and +/-3%, respectively), and does not require a specific column of derivatization. Mass spectrometry analysis of boron derivatives in different samples was also performed to ensure correct attribution of the CE peaks.
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Affiliation(s)
- Pier Luigi Mauri
- Istituto Tecnologie Biomediche-CNR, Via Fratelli Cervi, 93, 20090 Segrate, Milan, Italy.
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Abstract
Propolis is a resinous substance collected by honeybees from leaf buds and cracks in the bark of various plants, and it is composed of 50% resin (composed of flavonoids and related phenolic acids), 30% wax, 10% essential oils, 5% pollen and 5% various organic compounds. Propolis cannot be used as raw material, and it must be purified by extraction with solvents. This process should remove the inert material and preserve the polyphenolic fraction, which is considered to contribute more to the observed healing effects than the other propolis constituents. Therefore, the assay of propolis polyphenols is of interest, and this paper describes the results obtained in the analysis of propolis by means of a gradient HPLC or mass spectrometry. HPLC in the gradient mode and coupled with photodiode array detection remains the method of choice for the assay of most relevant components of propolis. Direct analysis by APCI-IT-MS represents a valuable alternative to obtain typical fingerprints of propolis and a reliable identification of a large number of propolis components.
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Affiliation(s)
- P G Pietta
- C.N.R., I.T.B., V.le F.lli Cervi, 93, Segrate (Mi), Italy.
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Abstract
Flavonoids are phenolic substances isolated from a wide range of vascular plants, with over 8000 individual compounds known. They act in plants as antioxidants, antimicrobials, photoreceptors, visual attractors, feeding repellants, and for light screening. Many studies have suggested that flavonoids exhibit biological activities, including antiallergenic, antiviral, antiinflammatory, and vasodilating actions. However, most interest has been devoted to the antioxidant activity of flavonoids, which is due to their ability to reduce free radical formation and to scavenge free radicals. The capacity of flavonoids to act as antioxidants in vitro has been the subject of several studies in the past years, and important structure-activity relationships of the antioxidant activity have been established. The antioxidant efficacy of flavonoids in vivo is less documented, presumably because of the limited knowledge on their uptake in humans. Most ingested flavonoids are extensively degraded to various phenolic acids, some of which still possess a radical-scavenging ability. Both the absorbed flavonoids and their metabolites may display an in vivo antioxidant activity, which is evidenced experimentally by the increase of the plasma antioxidant status, the sparing effect on vitamin E of erythrocyte membranes and low-density lipoproteins, and the preservation of erythrocyte membrane polyunsaturated fatty acids. This review presents the current knowledge on structural aspects and in vitro antioxidant capacity of most common flavonoids as well as in vivo antioxidant activity and effects on endogenous antioxidants.
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Affiliation(s)
- P G Pietta
- Institute of Advanced Biomedical Technologies, National Council of Research Via F.lli Cervi 93, 20090 Segrate (MI), Italy.
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Pietta PG, Mangano MF, Battaglia C, Salani G, Bernardi LR, De Bellis G. Application of capillary electrophoresis at low pH to oligonucleotides quality control. J Chromatogr A 1999; 853:355-8. [PMID: 10486742 DOI: 10.1016/s0021-9673(99)00451-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A method for oligonucleotides analysis by using capillary electrophoresis at low pH in free solution is described. It may be considered an alternative to classical analytical techniques which use basic buffers and require the presence of sieving media to separate oligonucleotides as a function of their length. On the contrary, at low pH oligo nucleotides can be separated only depending on their base composition. A large set of samples consisting of 72 synthetic oligonucleotides bearing a 5'-alkylamine moiety and designed for HLA genotyping were analysed. The quality of these synthetic oligos was easily assessed, and a single base difference in oligonucleotides of equal sequence was detected. The results suggest the application of this method to the emerging field of mutation detection and single nucleotide polymorfism analysis.
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Affiliation(s)
- P G Pietta
- Istituto di Tecnologie Biomediche Avanzate, Consiglio Nazionale delle Ricerche, Milan, Italy
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Mauri PL, Iemoli L, Gardana C, Riso P, Simonetti P, Porrini M, Pietta PG. Liquid chromatography/electrospray ionization mass spectrometric characterization of flavonol glycosides in tomato extracts and human plasma. Rapid Commun Mass Spectrom 1999; 13:924-931. [PMID: 10353226 DOI: 10.1002/(sici)1097-0231(19990530)13:10<924::aid-rcm588>3.0.co;2-g] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Flavonoids continue to attract wide attention as possible very useful agents for combating free radical pathologies, i.e. the pathological states associated with free radical overproduction. Commonly used methods for the analysis of plant flavonoids include high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). On the other hand, the soft-ionization approach based on electrospray ionization (ESI-MS) permits highly selective analysis of complex matrices. In this work, we examined firstly the ESI-MS behaviour of representative aglycones and glycosides of flavonols, flavones and isoflavones with the aim of suggesting a possible relationship between structure and mass spectra. Using HPLC coupled to a diode array detector (DAD) for on-line UV spectra acquisition, and in parallel to ESI-MS for mass spectra (LC/DAD-ESI-MS), we have developed methodology to observe flavonols directly in tomato puree extract. In this way, it has been possible to detect intact flavonol glycosides in tomato extracts and to characterize a flavonol trisaccharide. For the first time, using LC/ESI-MS, it has been possible to detect intact flavonol glycosides in plasma of healthy volunteers and to provide further evidence on the absorption of flavonoid glycosides after consumption of common vegetables like tomatoes.
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Affiliation(s)
- P L Mauri
- Istituto Tecnologie Biomediche Avanzate/CNR, Segrate-Milano, Italy.
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Mauri PL, Pietta PG, Maggioni A, Cerquetti M, Sebastianelli A, Mastrantonio P. Characterization of surface layer proteins from Clostridium difficile by liquid chromatography/electrospray ionization mass spectrometry. Rapid Commun Mass Spectrom 1999; 13:695-703. [PMID: 10343411 DOI: 10.1002/(sici)1097-0231(19990430)13:8<695::aid-rcm542>3.0.co;2-p] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Surface layers (S-layers) are regularly ordered protein subunits found as the outermost cell envelope component of many bacteria. Most S-layers are composed of a single protein or glycoprotein species with a molecular weight varying between 40 and 200 kDa. Clostridium difficile is the most common cause of antibiotic associated diarrhea (AAD) and pseudomembranous colitis (PMC) in humans. Detection of the S-layer in some C. difficile strains, and preliminary characterization of two glycoproteins, P36 and P47, involved in the composition of the S-layer of one of these strains (C. difficile C253), led us to investigate the most appropriate conditions for purification and chemical characterization of these proteins. This work describes the results obtained when liquid chromatography (LC) coupled to mass spectrometry (MS) using electrospray ionization was applied to the analysis of C. difficile S-layer proteins (SLPs). In this way the molecular weights of the two SLP components, P36 and P47, were detected to be 34,258 +/- 2 and 39,545 +/- 3 Da, respectively. These data deviate from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results by 1.85 and 7.5 kDa. To confirm the LC-MS results, an alternative molecular weight analysis was performed: the two S-layer proteins were isolated by semipreparative high performance liquid chromatography (HPLC), concentrated, and analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). The two SLP subunits were digested with protease V8, and the peptide maps were determined by LC-MS using a C18 column. Finally, preliminary results about peptide glycosylation were obtained.
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Affiliation(s)
- P L Mauri
- Istituto Tecnologie Biomediche Avanzate/CNR, Segrate-Milano, Italy.
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Abstract
Green tea contains relatively large amounts of catechins, that have been recognized to be efficient free-radical scavengers. In spite of a largely described antioxidant effect, the metabolic fate of catechins in humans has been scarcely studied. An infusion of green tea (about 400 mg of catechins) was given to healthy volunteers; plasma and urine samples were collected for 5 h and 2 days, respectively. Epigallocatechin gallate and epicatechin gallate were detected in plasma samples, reaching the maximum concentration (2 microM) at 2 h. Urine samples collected at 6-48 h contained detectable amounts of final catechin metabolites, including 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3-methoxy-4-hydroxy-hippuric acid and 3-methoxy-4-hydroxybenzoic acid (vanillic acid). The total content of these metabolites averaged 60 mg. The levels of free plasma catechins account only partly for the increased (approximately +20%) total radical-trapping antioxidant parameter (TRAP) detected after green tea intake. Catechin conjugates (glucuronide and sulphate) and metabolites may add further contribution and explain the measured TRAP increase.
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Pietta PG, Gardana C, Mauri PL. Identification of Gingko biloba flavonol metabolites after oral administration to humans. J Chromatogr B Biomed Sci Appl 1997; 693:249-55. [PMID: 9200545 DOI: 10.1016/s0378-4347(96)00513-0] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An extract of Ginkgo biloba leaves (EGb) was given to healthy volunteers. Urine samples were collected for 3 days, and blood samples were withdrawn every 30 min for 5 h. The samples were purified through SPE C18 cartridges and analyzed by reversed-phase LC-diode array detection for the presence of EGb metabolites. Only urine samples contained detectable amounts of substituted benzoic acids, i.e., 4-hydroxybenzoic acid conjugate, 4-hydroxyhippuric acid, 3-methoxy-4-hydroxyhippuric acid, 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, hippuric acid and 3-methoxy-4-hydroxybenzoic acid (vanillic acid). In contrast to rats no phenylacetic acid or phenylpropionic acid derivatives were found in urine, thus indicating that in humans a more extensive metabolism takes place. As for rats the metabolites found in human urines accounted for less than 30% of the flavonoids given. The same procedure was applied to blood samples, and no metabolites could be detected.
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Pietta PG, Mauri PL, Gardana C, Benazzi L. Assay of soluble guanylate cyclase activity by isocratic high-performance liquid chromatography. J Chromatogr B Biomed Sci Appl 1997; 690:343-7. [PMID: 9106063 DOI: 10.1016/s0378-4347(96)00414-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A HPLC method alternative to labelled or unlabelled procedures was developed for the assay of guanylate cyclase (GC) activity. The substrate (GTP) and the product (cGMP) of the enzymatic reaction were separated in the isocratic mode on a muBondapak C18 column. The activity of GC was linearly dependent on the amount of cGMP produced in the presence of sodium nitroprusside. This approach was applied to follow the purification of GC from bovine lung and to evaluate its stability in different storage conditions.
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Roggi C, Simonetti P, Maccarini L, Merlo E, Brusamolino A, Pellegrini N, Pietta PG. [Antioxidants in the diet of a general population]. Ann Ig 1996; 8:547-57. [PMID: 9244466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- C Roggi
- Dip. di Medicina Preventiva, Occupazionale e di Comunità, Sez. di Igiene, Università di Pavía
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Pietta PG, Gardana C, Mauri PL, Maffei-Facino R, Carini M. Identification of flavonoid metabolites after oral administration to rats of a Ginkgo biloba extract. J Chromatogr B Biomed Appl 1995; 673:75-80. [PMID: 8925077 DOI: 10.1016/0378-4347(95)00252-e] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An extract of Ginkgo biloba leaves (EGb) was administered by gastric probe to Wistar female rats, and urine and faeces samples were collected for 5 days and whole blood samples were withdrawn every 30 min for 6 h. After purification with SPE C18 cartridges, the samples were analysed by reversed-phase LC-diode array detection (LC-DAD) for residual flavonoid glycosides, aglycones and metabolites. No glycosides or aglycones were detected in urine, faeces or blood and extensive degradation of EGb flavonoids within 24 h was detected. Among the seven different phenylalkyl acids detected by LC-DAD, 3,4-dihydroxyphenylacetic acid (I), hippuric acid (II), 3-hydroxyphenylacetic acid (III), homovanillic acid (IV) and benzoic acid (VII) were directly confirmed by on-line mass spectrometry using an electrospray interface (ES-MS). Peaks V and VI needed to be collected and separately examined and they were found to be 3-(4-hydrophenyl)propionic acid and 3-(3-hydrophenyl)propionic acid, respectively. As further evidence, the identity of metabolites I, II, III, IV, V and VII was confirmed by co-chromatography with authentic standards.
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Pietta PG, Bruno A, Mauri PL, Gardana C, Maffei-Facino R, Carini M. Determination of sunscreen agents by micellar electrokinetic chromatography. J Pharm Biomed Anal 1995; 13:229-35. [PMID: 7619882 DOI: 10.1016/0731-7085(95)01260-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The separation of UV-A and UV-B sunscreens by micellar electrokinetic chromatography has been studied. The optimized method, which involves the presence of an anionic surfactant (sodium dodecyl sulphate) and an organic modifier in the background electrolyte, was applied to determine these sunscreens in cosmetic products. Identification was achieved by "on-line" UV spectra. Recovery was in the range of 88-92% and the lower limit of detection was 0.15 mg ml-1.
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Pace M, Agnellini D, Gardana C, Mauri PL, Pietta PG. High-performance liquid chromatographic assay of glycosyltransferases using flavonoids as substrate. J Chromatogr A 1995. [DOI: 10.1016/0021-9673(94)00943-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pietta PG, Mauri PL, Bruno A, Merfort I. MEKC as an Improved Method to Detect Falsifications in the Flowers of Arnica montana and A. chamissonis. Planta Med 1994; 60:369-72. [PMID: 17236057 DOI: 10.1055/s-2006-959503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
ARNICA MONTANA and ARNICA CHAMISSONIS ssp. FOLIOSA flowers are often adultered by blending them with those from HETEROTHECA INULOIDES. TLC, HPLC, and TSP LC/MS have been proposed to detect this kind of falsification. A new method based on micellar electrokinetic chromatography (MEKC) has been developed. This procedure permits us to characterize rapidly each drug and to detect easily falsifications from H. INULOIDES in ARNICA drugs.
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Affiliation(s)
- P G Pietta
- Dip. Scienze e Tecnologie Biomediche, via Celoria 2, I-20133 Milano, Italy
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Pietta PG, Mauri PL, Gardana C, Pace M, Agnellini D. Assay of urea by immobilized urease coupled to a differential pH-meter. Ann N Y Acad Sci 1992; 672:257-63. [PMID: 1476376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- P G Pietta
- Dipartimento di Scienze e Tecnologie Biomediche, Universita' di Milano, Italy
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Abstract
The purification and analysis of restriction fragments play a very important role in molecular biology but the traditional assay methods of DNA fragments, based on gel electrophoresis and caesium chloride gradient centrifugation, are time-consuming and difficult to quantify. High-performance liquid chromatography provides an alternative method which allows the direct quantitation of picogram amounts of eluents in short time. In the present work we report the separation of different restriction fragments, the purification of some fragments and the relationship between the length of double-stranded DNA fragments and peak areas.
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Affiliation(s)
- P L Mauri
- Istituto Tecnologie Biomediche Avanzate, CNR, Milan, Italy
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Abstract
High-performance liquid chromatography (HPLC) is a powerful technique which enables a reliable and quantitative determination of enzyme activities. The purpose of the work reported here was to develop an automatic assay of enzymatic activity. Using an automatic sample processor and injector, a program was developed which allows the complete automation of each step of analysis (calibration, enzymatic reaction, HPLC determination). This program can be adapted to different experimental requirements as each step can be performed independently and each input (time, volume, number of standards) is made by answering questions asked by instrument. Using this approach both kinetic and single-point determinations can be carried out, and in the latter case different samples can be analysed sequentially. This paper reports the automated analysis of trypsin.
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Affiliation(s)
- P L Mauri
- Istituto Tecnologie Biomediche Avanzate, CNR, Milan, Italy
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Pace M, Agnellini D, Lippoli G, Pietta PG, Mauri PL, Cinquanta S. Purification of NAD glycohydrolase from Neurospora crassa conidia by a polyclonal immunoadsorbent. J Chromatogr A 1991; 539:517-23. [PMID: 1828469 DOI: 10.1016/s0021-9673(01)83963-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
NAD glycohydrolase from Neurospora crassa conidia was purified by affinity chromatography on a column of polyclonal antibodies bound to an agarose matrix. The procedure was easy, non-denaturating and suitable for repetitive use of the gel. The enzyme obtained appeared homogeneous by sodiumdodecyl sulphate-polyacrylamide gel electrophoresis.
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Affiliation(s)
- M Pace
- Dipartimento di Scienze e Tecnologie Biomediche, University of Milan, Italy
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Mauri PL, Bitonti M, Pace M, Pietta PG, Agnellini D. Automatic computation of enzyme kinetics by HPLC. Comput Appl Biosci 1990; 6:395-8. [PMID: 2175245 DOI: 10.1093/bioinformatics/6.4.395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Enzyme activity can be easily measured by HPLC using traces of the product itself as an internal standard. Our procedure involved the development of an equation using the experimental data obtained in the kinetic assay. The entire procedure can thus be automated and a computer program is presented here for facilitating the assay and saving time. The determination of the activity of NAD kinase is reported as an example.
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Affiliation(s)
- P L Mauri
- Dipartimento di Scienze e Tecnologie Biomediche, University of Milano, Italy
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Affiliation(s)
- M Pace
- Dipartimento di Scienze e Technologie Biomediche, Università di Milano, Italy
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Affiliation(s)
- M Pace
- Dipartimento di Scienze e Tecnologie Biomediche, University of Milano, Italy
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Agostoni A, Stabilini R, Perrella M, Pietta PG, Pace M, Russo V, Sabbioneda L. Functional properties of glutaraldehyde cross-linked Hb in the presence of CO2 and/or inositolhexaphosphate (IHP). ASAIO Trans 1987; 33:372-3. [PMID: 3118915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- A Agostoni
- Institute of Clinical Medicine V, University of Milan, Italy
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Pace M, Pietta PG, Fiorino A, Pocaterra E, Dixon JE. Nonspecific reaction of a thiol: protein disulfide oxidoreductase with the disulfide bonds of insulin. Experientia 1985; 41:1332-5. [PMID: 3899711 DOI: 10.1007/bf01952081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A thiol: protein disulfide oxidoreductase from bovine liver was isolated after separation from protein disulfide isomerase. The enzyme, after activation (reduction) with glutathione, was reacted with stoichiometric amounts of insulin and the sulfhydryl groups of the partially reduced hormone were labeled with iodo (l-14C)acetamide. After separation of the insulin chains, the radioactivity was found in both the peptides, with a ratio A-chain/B-chain equal to 2/1.
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Pace M, Agnellini D, Pietta PG, Cocilovo A, Bonizzi L. Preparation of immobilized NAD glycohydrolase from Neurospora crassa conidia by hydrophobic interaction--characteristics of the enzyme derivative. Prep Biochem 1984; 14:349-62. [PMID: 6096842 DOI: 10.1080/10826068408070640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
NAD glycohydrolase from Neurospora crassa conidia has been immobilized by hydrophobic interaction on Sepharose 4B beads coated with propyl residues through CNBr activation. The bond resulted stable under a wide range of conditions (ionic strength, temperature, pH). As a result of immobilization the pH optimum for catalytic activity shifted by about 0.2 pH unit in the acidic direction, to lie between 7.5 and 7.3. The stability of the enzymatic activity was largely enhanced by effect of immobilization but the Km value towards NAD+ was increased compared with that of the free enzyme (1 X 10(-3) and 2 X 10(-4) M respectively).
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Pietta PG, Pace M, Palazzini G, Agostoni A. Comparison of the properties of human hemoglobin covalently bound to carboxyl dextrans with free and polymerized hemoglobin. Prep Biochem 1984; 14:313-329. [PMID: 6083557 DOI: 10.1080/10826068408070638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Human stroma-free hemoglobin (SFH) was coupled in the oxy or deoxy conformations to carboxyldextrans through amide bonds. The complexes were analysed by gel permeation high performance chromatography, and their molecular mass distribution ranged from 90,000 to 300,000. Covalent coupling of SFH to carboxyldextrans determined an increase of the oxygen affinity when compared to free SFH. The P50 of the complex formed from carboxyldextrans and SFH in the oxy state was lower than that of the derivative obtained from SFH in the reduced state. On the other hand, glutaraldehyde cross-linked SFH still showed cooperativity when reacted in the deoxy state and in the presence of pyridoxal phosphate, and its oxygen affinity was similar to that of the free pyridoxylated SFH. These results lead to exclude the potential use of these dextran-SFH complexes as oxygen carriers.
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Pietta PG, Agnellini D, Pace M. Colorimetric determination of 1-(4'-nitrophenyl)-2-aminopropane-1,3-diol with 2,4,6-trinitrobenzenesulfonic acid in the presence of chloramphenicol. J Pharm Sci 1979; 68:1565-6. [PMID: 43388 DOI: 10.1002/jps.2600681231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A colorimetric method based on the interaction between the chloramphenicol degradation product 1-(4'-nitrophenyl)-2-aminopropane-1,3-diol and the 2,4,6-trinitrobenzenesulfonic acid reagent was developed. Analytical solutions were reacted with the reagent at pH 9.1 for 20 min at room temperature, and the resulting color was measured at 340 nm. A linear relationship between absorbance and concentration occurred within the 5--25-micrograms/ml range under the conditions studied. Replicate analyses were in good agreement. An average recovery of 99.4 +/- 0.4% was obtained for the synthetic mixtures.
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Mazzola G, Cremonesi P, Colombi S, Vecchio G, Agnellini D, Pietta PG. [Use of immobilized enzymes in detoxification. II. Immobilization and characterization of enzymes on hollow fiber devices]. Minerva Nefrol 1979; 26:185-7. [PMID: 471347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Baldini G, Masserini G, Pietta PG, Cremonesi P, Mazzola G, Vecchio G. [The use of immobilized enzymes in detoxification. I. Study on the physical characteristics of the membrane as a function of the immobilization process]. Minerva Nefrol 1979; 26:181-4. [PMID: 471346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Brenna O, Roux B, Pietta PG, Pace M. Phenol-containing adsorbents for the affinity chromatography purification of some NAD(H)-dependent dehydrogenases. FEBS Lett 1977; 76:246-9. [PMID: 862905 DOI: 10.1016/0014-5793(77)80161-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
A crude preparation of alkaline phosphatase (EC 3.1.3.1) from calf intestinal mucosa was purified by affinity chromatography on Sepharose-bound derivatives of arsanilic acid, which was found to be a competitive inhibitor of the enzyme. Three biospecific adsorbents were prepared for the chromatography, and the best results were obtained with a tyraminyl-Sepharose derivative coupled with the diazonium salt derived from 4-(p-aminophenylazo)phenylarsonic acid. Alkaline phosphatase was the only enzyme retained by the affinity column in the absence of Pi. The enzyme eluted by phosphate buffer had a specific activity of about 1200 units per mg of protein at pH 10.0, with 5.5mM-p-nitrophenyl phosphate as the substrate.
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Pietta PG, Cavallo PF, Takahashi K, Marshall GR. Preparation and use of benzhydrylamine polymers in peptide synthesis. II. Syntheses of thyrotropin releasing hormone, thyrocalcitonin 26-32, and eledoisin. J Org Chem 1974; 39:44-8. [PMID: 4206303 DOI: 10.1021/jo00915a008] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Pietta PG, Cavallo P, Marshall GR. 2,4-dimethoxybenzyl as a protecting group for glutamine and asparagine in peptide synthesis. J Org Chem 1971; 36:3966-70. [PMID: 5127993 DOI: 10.1021/jo00824a025] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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