Isolation and Identification of Peptidic α-Glucosidase Inhibitors Derived from Sardine Muscle Hydrolyzate

Abstract We report here the isolation of a-glucosidase (AGH) inhibitory peptides derived from sardine muscle hydrolyzate, which was prepared by digestion with Bacillus licheniformis alkaline protease. As a result of reversed-phase HPLC purification, two AGH inhibitory peptides were isolated from a DEAE -Sephadex A-25 column eluate. The peptides were identified as follows: Val-Trp (IC50 = 22.6 mᴍ) and Try -Tyr -Pro -Leu (IC50 = 3.7 mᴍ). AGH inhibitory studies of Try -Tyr -Pro -Leu and its derivatives demonstrated the importance of the tri-peptide chain length as well as the hydrophobic aromatic amino acid tyrosine at the N-terminus, aliphatic amino acids at the C-terminus, as well as an amide proton from the peptide chain at the middle position of the tri-peptide to develop AGH inhibition activity.

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Isolation and Identification of Neo-Clerodane Diterpenes from Ajuga Nipponensis Makino

Natural Product Communications ◽

10.1177/1934578x0600100302 ◽

2006 ◽

Vol 1 (3) ◽

pp. 1934578X0600100 ◽

Cited By ~ 1

Author(s):

Josep Coll ◽

Yudelsy A. Tandrón

Keyword(s):

Spodoptera Littoralis ◽

Reversed Phase ◽

Chromatographic Behavior ◽

Spectral Studies ◽

Two Dimensional ◽

Reversed Phase Hplc ◽

Antifeedant Activity ◽

Isolation And Identification ◽

Aerial Parts ◽

Clerodane Diterpenes

An extract of the aerial parts of Ajuga nipponensis Makino was examined by HPLC for neo-clerodane diterpenes. The suitability of reversed-phase HPLC for the semi-preparative fractionation of this extract was explored, resulting in the isolation of two new neo-clerodane diterpenes, which we have named ajuganipponin A, (12S)-1β,6α,19-triacetoxy-4α,18-epoxy-12-tigloyl-neo-clerod-13-en-15,16-olide (AJNP A, 1), and ajuganipponin B, (12S)-6α,19-diacetoxy-4α,18-epoxy-12-tigloyl-neo-clerod-13-en-15,16-olide (AJNP B, 6). In addition, ajugamarins A2 and F4, ajugamacrin B, ajugacumbin A and ajugatakasin A, were newly isolated compounds from A. nipponensis, along with the previously reported ajugamarins A1, B2 and L2 (ajugacumbin B). The structures of all the isolated compounds were unambiguously elucidated based on extensive NMR spectral studies (one and two-dimensional experiments) and their reversed-phase chromatographic behavior was established. The antifeedant activity of the isolated diterpenes against Spodoptera littoralis is also reported here.

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ON THE IDENTIFICATION OF POLYMORPHIC SITES IN HUMAN FIBRINOGEN PEPTIDE CHAINS

10.1055/s-0038-1643327 ◽

1987 ◽

Author(s):

S Wilhelm ◽

A Henschen

Keyword(s):

High Performance ◽

Reversed Phase ◽

Peptide Chain ◽

Molecular Forms ◽

Side Chain ◽

Human Fibrinogen ◽

C Terminus ◽

Length Analysis ◽

Counter Current ◽

Counter Current Distribution

Human fibrinogen has repeatedly been shown to occur in a great number of different molecular forms. Some types of heterogeneity are evident already from variations in solubility properties and in ion-exchange-chromatographic as well as gel-electrophoretic behaviour of the total molecule and of its peptide chain components. The reason for these variations are partly known.Thus, degradation of the C-terminal parts and phosphorylation of two serine residues gives rise to heterogeneity in the Aα-chain. Differences in the sialylation of the carbohydrate side chain causes heterogeneity both in the Bβ- and the γ-chain. Differences in chain length at the C-terminus of the γ-chain are responsible for additional variation. All these variants are expected to exist in each human being. An other category of human fibrinogen variants may be due to genetic polymorphism within the population, i.e. the presence of inherited, common, normal variants. Seven sites of microheterogeneity have so far been tentatively identified, mainly by disagreements between protein and DNA sequence analyses. Three of the sites are located in the Aα-chain (positions 47, 296 and 312), three in the Bβ-chain (positions 162, 296 and 44-8) and one in the γ-chain (position 88). The aim of the present study was to identify these sites on the proteinchemical level in pooled plasma as well as in plasma from single individuals, especially various members of the same family. For this purpose suitable fibrinogen fragments containing the tentatively microheterogeneous sites were isolated after cleavage of fibrinogen with cyanogen bromide, trypsin and/or chymotrypsin by repeated fractionations by means of conventional and reversed-phase high-performance liquid chromatography and counter-current distribution. The components were characterized by N-terminal sequence and amino acid composition. Polymorphism in human fibrinogen has previously only once been identified by restriction fragment length analysis in a non-transcribed region of the Aα-chain locus but never in the transcribed regions, i.e. the peptide chains.The present investigation will allow the estimation of the number of peptide chain haplotypes and their possible correlation to other genetic variants of fibrinogen.

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Isolation and identification of a C39 demethylated metabolite of rapamycin from pig liver microsomes and evaluation of its immunosuppressive activity

Clinical Chemistry ◽

10.1093/clinchem/44.3.532 ◽

1998 ◽

Vol 44 (3) ◽

pp. 532-538 ◽

Cited By ~ 3

Author(s):

Marc J M Nickmilder ◽

Dominique Latinne ◽

Jean-Paul De Houx ◽

Roger K Verbeeck ◽

Georges J J Lhoëst

Keyword(s):

Parent Compound ◽

Liver Microsomes ◽

Reversed Phase ◽

Reversed Phase Hplc ◽

Immunosuppressive Activity ◽

Isolation And Identification ◽

Fk 506 ◽

Pig Liver ◽

Structural Modifications

Abstract We studied in vitro metabolism of rapamycin using pig liver microsomes. After extraction of the metabolites from the incubation medium, the crude metabolite extract was submitted to normal and subsequently to reversed-phase HPLC chromatography. We describe in the current study a metabolite of retention time 23.2 min collected from reversed-phase HPLC and identified by fast atom bombardment mass spectrometry (MS) and electrospray MS-MS as a C39 demethylated rapamycin metabolite. In vitro immunosuppressive activity of this metabolite, determined by the mixed lymphocyte reaction, was negligible compared with that of the parent compound. The decrease of in vitro immunosuppressive activity compared with the parent compound is likely to be attributed to important structural modifications of the rapamycin binding region to the FK-506 binding protein.

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Isolation and Identification of a Potent PTP1B Inhibitor, Ursolic Acid, from Carolina Jasmine (Gelsemium sempervirens (L.) J.St.-Hil.)

Letters in Organic Chemistry ◽

10.2174/1570178617666200409101248 ◽

2020 ◽

Vol 17 (12) ◽

pp. 939-943

Author(s):

Toshiro Noshita ◽

Yusuke Kakizoe ◽

Satoshi Tanabe ◽

Hidekazu Ouchi ◽

Akihiro Tai

Keyword(s):

Ursolic Acid ◽

Protein Tyrosine Phosphatase ◽

Tyrosine Phosphatase ◽

Active Agent ◽

Protein Tyrosine Phosphatase 1B ◽

Inhibiting Activity ◽

Inhibition Activity ◽

Isolation And Identification ◽

Gelsemium Sempervirens

Extracts of Carolina jasmine (Gelsemium sempervirens (L.) J.St.-Hil.) petals were evaluated in vitro for inhibition activity against protein tyrosine phosphatase 1B (PTP1B). The principle active agent was also isolated from the extract and identified as ursolic acid (1). This is the first report of ursolic acid from G. sempervirens and of PTP1B-inhibiting activity in the genus Gelsemium.

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Cholecystokinin Heptapeptide Analogues with Multiple Modification in Peptide Chain

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19932761 ◽

1993 ◽

Vol 58 (11) ◽

pp. 2761-2765 ◽

Cited By ~ 2

Author(s):

Jan Hlaváček ◽

Jana Pírková ◽

Miroslava Žertová ◽

Jan Pospíšek ◽

Lenka Maletínská ◽

...

Keyword(s):

Solid Phase Synthesis ◽

Solid Phase ◽

Peptide Chain ◽

Phase Synthesis ◽

C Terminus

Using solid phase synthesis we prepared the cholecystokinin fragment Boc-CCK-7 (Boc-Tyr(SO3-Na+)-Met-Gly-Trp-Met-Asp-Phe-NH2) Ia and its seven analogues Ib - Ih. In the analogues Ib and Ic the Met residue in the carboxyterminal part of the molecule was substituted for L- or D-Phe Me3. In the analogues Id and Ie with Phe residue substituted by L- or D-Phe Me3 the Neo was inserted in the place of this Met residue and in the analogues If and Ig, an addition to PheMe3 substitution in the carboxyterminus, both Met residues were replaced for Neo. This dual substitution for Met residues was also applied in the analogue Ih with coded Phe residue in the C-terminus.

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Determination of Palladium Ion in River Water by Solvent Extraction with 5-Methyl-1,3,4-Thiodiazole-2-thiol Followed by Reversed Phase HPLC

Journal of Liquid Chromatography &amp Related Technologies ◽

10.1080/10826070802424824 ◽

2008 ◽

Vol 31 (19) ◽

pp. 2988-3000 ◽

Cited By ~ 5

Author(s):

Susumu Ichinoki ◽

Takako Mikami ◽

Youichi Fujii

Keyword(s):

Solvent Extraction ◽

River Water ◽

Reversed Phase ◽

Reversed Phase Hplc ◽

Palladium Ion

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A Reversed-phase HPLC Study of the Complexation of Benzene Derivatives Guest Molecules with 5,17-bis(N-Tolyliminomethyl)-25,27-dipropoxycalix[4]arene in Acetonitrile–Water Solution

Journal of Chemical Research ◽

10.1177/174751989902300136 ◽

1999 ◽

Vol 23 (1) ◽

pp. 60-61

Author(s):

O. I. Kalchenko ◽

A. V. Solovyov ◽

J. Lipkowski ◽

V. I. Kalchenko

Keyword(s):

Stability Constants ◽

Water Solution ◽

Reversed Phase ◽

Benzene Derivatives ◽

Reversed Phase Hplc ◽

Guest Molecules ◽

Hplc Study

Stability constants of the host–guest complexes of 5,17-bis( N-tolyliminomethyl)-25,27-dipropoxycalix[4]arene with benzene derivatives were determined by reversed-phase HPLC in acetonitrile–water solution.

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