MyMedR

Fulltext Metabolite Fingerprinting Using 1H-NMR Spectroscopy and Chemometrics for Classification of Three Curcuma Species from Different Origins

Nurani LH, Rohman A, Windarsih A, Guntarti A, Riswanto FDO, Lukitaningsih E, et al.

Molecules, 2021 Dec 16;26(24).

PMID: 34946709 DOI: 10.3390/molecules26247626

Curcuma longa, Curcuma xanthorrhiza, and Curcuma manga have been widely used for herbal or traditional medicine purposes. It was reported that turmeric plants provided several biological activities such as antioxidant, anti-inflammatory, hepatoprotector, cardioprotector, and anticancer activities. Authentication of the Curcuma species is important to ensure its authenticity and to avoid adulteration practices. Plants from different origins will have different metabolite compositions because metabolites are affected by soil nutrition, climate, temperature, and humidity. 1H-NMR spectroscopy, principal component analysis (PCA), and orthogonal projections to latent structures-discriminant analysis (OPLS-DA) were used for authentication of C. longa, C. xanthorrhiza, and C. manga from seven different origins in Indonesia. From the 1H-NMR analysis it was obtained that 14 metabolites were responsible for generating classification model such as curcumin, demethoxycurcumin, alanine, methionine, threonine, lysine, alpha-glucose, beta-glucose, sucrose, alpha-fructose, beta-fructose, fumaric acid, tyrosine, and formate. Both PCA and OPLS-DA model demonstrated goodness of fit (R2 value more than 0.8) and good predictivity (Q2 value more than 0.45). All OPLS-DA models were validated by assessing the permutation test results with high value of original R2 and Q2. It can be concluded that metabolite fingerprinting using 1H-NMR spectroscopy and chemometrics provide a powerful tool for authentication of herbal and medicinal plants.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular*

Fulltext Botanical Origin Differentiation of Malaysian Stingless Bee Honey Produced by Heterotrigona itama and Geniotrigona thoracica Using Chemometrics

Ng WJ, Sit NW, Ooi PA, Ee KY, Lim TM

Molecules, 2021 Dec 16;26(24).

PMID: 34946710 DOI: 10.3390/molecules26247628

Stingless bee honey, specifically honeydew honey, is generally valued for its better health benefits than those of most blossom types. However, scientific studies about the differentiation of stingless bee honey based on honeydew and blossom origins are very limited. In this study, 13C NMR spectroscopy was employed to quantify the seven major sugar tautomers in stingless bee honey samples, and the major sugar compositions of both honeydew and blossom types were found not significantly different. However, several physicochemical properties of honeydew honey including moisture content, free acidity, electrical conductivity, ash content, acetic acid, diastase, hydrogen peroxide, and mineral elements levels were significantly higher; while total soluble solid, proline, and hydroxymethylfurfural were significantly lower than blossom honey. Greater antioxidant capacity in honeydew honey was proven with higher total phenolic compounds, ABTS, DPPH, superoxide radical scavenging activities, peroxyl radical inhibition, iron chelation, and ferric reducing power. Using principal component analysis (PCA), two clusters of stingless bee honey from the honeydew and blossom origin were observed. PCA also revealed that the differentiation between honeydew and blossom origin of stingless bee honey is possible with certain physicochemical and antioxidant parameters. The combination of NMR spectroscopy and chemometrics are suggested to be useful to determine the authenticity and botanical origin of stingless bee honey.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular*

Fulltext Straightforward synthesis of novel 1-(2'-α-O-D-glucopyranosyl ethyl) 2-arylbenzimidazoles

Arumugam N, Abdul Rahim AS, Abd Hamid S, Osman H

Molecules, 2012 Aug 17;17(8):9887-99.

PMID: 22902883 DOI: 10.3390/molecules17089887

A series of novel 1-(2'-α-O-D-glucopyranosyl ethyl) 2-arylbenzimidazoles has been prepared via one-pot glycosylation of ethyl-1-(2'-hydroxyethyl)-2-arylbenzimidazole-5-carboxylate derivatives. Synthesis of the 2-arylbenzimidazole aglycones from 4-fluoro-3-nitrobenzoic acid was accomplished in four high-yielding steps. The reduction and cyclocondensation steps for the aglycone synthesis proceeded efficiently under microwave irradiation to afford the appropriate benzimidazoles in excellent yields within 2-3 min. Glycosylation of the hydroxyethyl aglycones with the perbenzylated 1-hydroxy- glucopyranose, pretreated with the Appel-Lee reagent, followed by catalytic hydrogenolysis delivered the desired 1-(2'-α-O-D-glucopyranosyl ethyl) 2-aryl-benzimidazoles in a simple and straightforward manner.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Fulltext A new 4alpha-methylated sterol from a Nephthea sp. (Nephtheidae) Bornean soft coral

Ishii T, Matsuura H, Zhaoqi Z, Vairappan CS

Molecules, 2009;14(9):3360-6.

PMID: 19783930 DOI: 10.3390/molecules14093360

A new 4alpha-methyl sterol, 4alpha-methyl-ergosta-6,8(14),22E-triene-3beta-ol (1), was isolated along with cholesterol from a Nephthea sp. Bornean soft coral The structure of compound 1 was elucidated on the basis of spectroscopic analysis and comparison of the data with those of the related compounds.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Pterulamides I-VI, linear peptides from a Malaysian Pterula sp

Lang G, Mitova MI, Cole AL, Din LB, Vikineswary S, Abdullah N, et al.

J Nat Prod, 2006 Oct;69(10):1389-93.

PMID: 17067148

Six new linear peptides, pterulamides I-VI (1-6), were isolated from the fruiting bodies of a Malaysian Pterula species. The structures were elucidated by MS and 2D NMR experiments, and the absolute configurations of the constituent amino acids established using Marfey's method. The pterulamides are mainly assembled from nonpolar N-methylated amino acids and, most interestingly, have non-amino-acid N-terminal groups, among them the unusual cinnamoyl, (E)-3-methylsulfinylpropenoyl, and (E)-3-methylthiopropenoyl groups. Furthermore, pterulamides I-V are the first natural peptides with a methylamide C-terminus. Pterulamides I and IV are cytotoxic against the P388 cell line with IC50 values of 0.55 and 0.95 microg/mL (0.79 and 1.33 microM), respectively.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Urine NMR Metabolomic Study on Biochemical Activities to Investigate the Effect of P. betle Extract on Obese Rats

Abdul Ghani ZDF, Ab Rashid AH, Shaari K, Chik Z

Appl Biochem Biotechnol, 2019 Oct;189(2):690-708.

PMID: 31111377 DOI: 10.1007/s12010-019-03042-w

The present studies are to evaluate the ability of PB to induce weight loss and urine metabolite profile of Piper betle L. (PB) leaf extracts using metabolomics approach. Dried PB leaves were extracted with ethanol 70% and the studies were performed in different groups of rats fed with high fat (HFD) and normal diet (ND). Then, fed with the PB extract with 100, 300, and 500 mg/kg and two negative control groups given water (WTR). The body weights were monitored and evaluated. Urine was collected and 1H NMR-based metabolomics approach was used to detect the metabolite changes. Results showed that PB-treated group demonstrated inhibition of body weight gain. The trajectory of urine metabolites showed that PB-treated group gave the different distribution from week 12 to 16 compared with the control groups. In 1H NMR metabolomic approach analysis, the urine metabolites gave the best separation in principle component 1 and 3, with 40.0% and 9.56% of the total variation. Shared and unique structures (SUS) plot model showed that higher concentration PB-treated group was characterized by high level of indole-3-acetate, aspartate, methanol, histidine, and creatine, thus caused an increased the metabolic function and maintaining the body weight of the animals treated.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular*

Biologically active indole and bisindole alkaloids from Tabernaemontana divaricata

Kam TS, Pang HS, Lim TM

Org Biomol Chem, 2003 Apr 21;1(8):1292-7.

PMID: 12929658

The ethanol extract of the leaves of Tabernaemontana divaricata (double flower variety) provided a total of 23 alkaloids, including the new aspidosperma alkaloids, taberhanine, voafinine, N-methylvoafinine, voafinidine, voalenine and the new bisindole alkaloid, conophyllinine in addition to the previously known, biologically active bisindole, conophylline and its congener, conofoline. The structures of the new alkaloids were established by spectroscopic methods. The preparation and characterization of the corresponding quinones of the biologically active bisindoles are also described in relation to a structure-activity study of these compounds with respect to their action in stimulating insulin expression.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Coumarins from Malaysian Micromelum minutum

Rahmani M, Susidarti RA, Ismail HB, Sukari MA, Hin TY, Lian GE, et al.

Phytochemistry, 2003 Oct;64(4):873-7.

PMID: 14559284

In a continuation of our study of the Rutaceae, detailed chemical investigation on Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia gave four new coumarins. The structures of the coumarins have been fully characterised by spectroscopic methods as 3",4"-dihydrocapnolactone 1, 2',3'-epoxyisocapnolactone 2, 8-hydroxyisocapnolactone-2',3'-diol 3 and 8-hydroxy-3",4"-dihydrocapnolactone-2',3'-diol 4.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Lumutinines A-D, linearly fused macroline-macroline and macroline-sarpagine bisindoles from Alstonia macrophylla

Lim SH, Tan SJ, Low YY, Kam TS

J Nat Prod, 2011 Dec 27;74(12):2556-62.

PMID: 22148233 DOI: 10.1021/np200730j

Four new linearly fused bisindole alkaloids, lumutinines A-D (1-4), were isolated from the stem-bark extract of Alstonia macrophylla. Lumutinines A (1) and B (2) represent the first examples of linear, ring A/F-fused macroline-macroline-type bisindoles, while lumutinines C (3) and D (4) were constituted from the union of macroline and sarpagine moieties. A reinvestigation of the stereochemical assignment of alstoumerine (8) by NMR and X-ray diffraction analyses indicated that the configuration at C-16 and C-19 required revision.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Fulltext Synthesis, characterization and fluorescent property evaluation of 1,3,5-triaryl-2-pyrazolines

Hasan A, Abbas A, Akhtar MN

Molecules, 2011 Sep 13;16(9):7789-802.

PMID: 22143543 DOI: 10.3390/molecules16097789

A series of 1,3,5-triaryl-2-pyrazolines was synthesized by dissolving the corresponding 4-alkoxychalcones in glacial acetic acid containing a few drops of concentrated hydrochloric acid. This step was followed by the addition of (3,4-dimethylphenyl) hydrazaine hydrochloride. Finally the target compounds were precipitated by pouring the reaction mixture onto crushed ice. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The 1,3,5-triaryl-2-pyrazolines bearing homologous alkoxy groups were found to possess fluorescence properties in the blue region of the visible spectrum when irradiated with ultraviolet radiation. The fluorescent behavior of these compounds was studied by UV-Vis and emission spectroscopy, performed at room temperature.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Perhentidines A-C: macroline-macroline bisindoles from Alstonia and the absolute configuration of perhentinine and macralstonine

Lim SH, Low YY, Tan SJ, Lim KH, Thomas NF, Kam TS

J Nat Prod, 2012 May 25;75(5):942-50.

PMID: 22559995 DOI: 10.1021/np300120p

Three new bisindole alkaloids of the macroline-macroline type, perhentidines A-C (1-3), were isolated from the stem-bark extract of Alstonia macrophylla and Alstonia angustifolia. The structures of these alkaloids were established on the basis of NMR and MS analyses. The absolute configurations of perhentinine (4) and macralstonine (5) were established by X-ray diffraction analyses, which facilitated assignment of the configuration at C-20 in the regioisomeric bisindole alkaloids perhentidines A-C (1-3). A potentially useful method for the determination of the configuration at C-20 based on comparison of the NMR chemical shifts of the bisindoles and their acetate derivatives, in these and related bisindoles with similar constitution and branching of the monomeric units, is also presented.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

A new furanoxanthone from Garcinia mangostana

Ee GC, See I, Teh SS, Daud S

J Asian Nat Prod Res, 2014;16(7):790-4.

PMID: 24670077 DOI: 10.1080/10286020.2014.901313

Our phytochemical study on the stem bark of Garcinia mangostana has led to the discovery of a new furanoxanthone, mangaxanthone A (1), together with five known analogs. The five known analogs that were isolated are α-mangostin (2), β-mangostin (3), cowagarcinone B (4), and dulcisxanthone F (5). The structural elucidations of these compounds were carried out by interpreting their spectroscopic data, mainly 1D and 2D NMR spectra and MS.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Prenylated flavanones and flavanonols as chemical markers in Glycosmis species (Rutaceae)

Lukaseder B, Vajrodaya S, Hehenberger T, Seger C, Nagl M, Lutz-Kutschera G, et al.

Phytochemistry, 2009 May;70(8):1030-7.

PMID: 19535116 DOI: 10.1016/j.phytochem.2009.05.007

Fifteen prenylated or geranylated flavanones and flavanonols were isolated from the leaf extracts of different Glycosmis species collected in Thailand and Malaysia. All structures were elucidated by spectroscopic methods, especially 1D and 2D NMR. Six compounds were described for the first time and two were only known so far as synthetic products. The chemotaxonomic significance of flavanoid accumulation within the genus Glycosmis is highlighted.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Four tetracyclic oxindole alkaloids and a taberpsychine derivative from a Malayan Tabernaemontana

Lim KH, Sim KM, Tan GH, Kam TS

Phytochemistry, 2009 Jun;70(9):1182-1186.

PMID: 19643450 DOI: 10.1016/j.phytochem.2009.06.010

Four tetracyclic oxindole alkaloids, 7(R)- and 7(S)-geissoschizol oxindole (1 and 2), 7(R),16(R)- and 7(S),16(R)-19(E)-isositsirikine oxindole (3 and 4), in addition to a taberpsychine derivative, N(4)-demethyltaberpsychine (5), were isolated from the Malayan Tabernaemontana corymbosa and the structures were established using NMR and MS analysis.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Fulltext Synthesis, characterization and antifungal evaluation of 5-substituted-4-amino-1,2,4-triazole-3-thioesters

Hasan A, Thomas NF, Gapil S

Molecules, 2011;16(2):1297-309.

PMID: 21278680 DOI: 10.3390/molecules16021297

A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Fulltext Synthesis of new azo compounds based on N-(4-hydroxypheneyl)maleimide and N-(4-methylpheneyl)maleimide

Mohammed IA, Mustapha A

Molecules, 2010;15(10):7498-509.

PMID: 20975631 DOI: 10.3390/molecules15107498

Maleic anhydride was reacted with p-aminophenol and p-toluidine in the presence of di-phosphorus pentoxide (P₂O₅) as a catalyst to produce two compounds: N-(4-hydroxy-phenyl)maleimide (I) and N-(4-methylphenyl)maleimide (II). The new azo compounds I(a-c) and II(a-c) were prepared by the reaction of I and II with three different aromatic amines, namely aniline, p-aminophenol and p-toluidine. The structures of these compounds were confirmed by CHN, FT-IR, ¹H-NMR, ¹³C-NMR, mass spectrum and UV/Vis spectroscopy.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Fulltext Anthraquinones with antiplasmodial activity from the roots of Rennellia elliptica Korth. (Rubiaceae)

Osman CP, Ismail NH, Ahmad R, Ahmat N, Awang K, Jaafar FM

Molecules, 2010;15(10):7218-26.

PMID: 20966871 DOI: 10.3390/molecules15107218

Dichloromethane root extract of Rennellia elliptica Korth. showed strong inhibition of Plasmodium falciparum growth in vitro with an IC₅₀ value of 4.04 µg/mL. A phytochemical study of the dichloromethane root extract has led to the isolation and characterization of a new anthraquinone, 1,2-dimethoxy-6-methyl-9,10-anthraquinone (1), and ten known anthraquinones: 1-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone (2), nordamnacanthal (3), 2-formyl-3-hydroxy-9,10-anthraquinone (4), damnacanthal (5), lucidin-ω-methyl ether (6), 3-hydroxy-2-methyl-9,10-anthraquinone (7), rubiadin (8), 3-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone (9), rubiadin-1-methyl ether (10) and 3-hydroxy-2-hydroxymethyl-9,10-anthraquinone (11). Structural elucidation of all compounds was accomplished by modern spectroscopic methods, notably 1D and 2D NMR, IR, UV and HREIMS. The new anthraquinone 1, 2-formyl-3-hydroxy-9,10-anthraquinone (4) and 3-hydroxy-2-methyl-9,10-anthraquinone (7) possess strong antiplasmodial activity, with IC₅₀ values of 1.10, 0.63 and 0.34 µM, respectively.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Voatinggine and tabertinggine, pentacyclic indole alkaloids derived from an iboga precursor via a common cleavamine-type intermediate

Nge CE, Gan CY, Low YY, Thomas NF, Kam TS

Org. Lett., 2013 Sep 20;15(18):4774-7.

PMID: 23991636 DOI: 10.1021/ol4021404

Two new indole alkaloids, voatinggine (1) and tabertinggine (2), which are characterized by previously unencountered natural product skeletons, were isolated from a Malayan Tabernaemontana species. The structures and absolute configuration of these alkaloids were determined using NMR and MS analysis, and X-ray diffraction analysis. A possible biogenetic pathway to these novel alkaloids from an iboga precursor, and via a common cleavamine-type intermediate, is presented.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Biosynthetic Enantiodivergence in the Eburnane Alkaloids from Kopsia

Chong KW, Yeap JS, Lim SH, Weber JF, Low YY, Kam TS

J Nat Prod, 2017 11 22;80(11):3014-3024.

PMID: 29087707 DOI: 10.1021/acs.jnatprod.7b00621

Reexamination of the absolute configuration of recently isolated eburnane alkaloids from Malaysian Kopsia and Leuconotis species by X-ray diffraction analysis and ECD/TDDFT has revealed the existence of biosynthetic enantiodivergence. Three different scenarios are discerned with respect to the composition of the enantiomeric eburnane alkaloids in these plants: first, where the new eburnane congeners possess the same C-20, C-21 absolute configurations as the common eburnane alkaloids (eburnamonine, eburnamine, isoeburnamine, eburnamenine) occurring in the same plant; second, where the new eburnane congeners possess opposite or enantiomeric C-20, C-21 absolute configurations compared to the common eburnane alkaloids found in the same plant; and, third, where the four common eburnane alkaloids were isolated as racemic or scalemic mixtures, while the new eburnane congeners were isolated as pure enantiomers with a common C-20, C-21 configuration (20α, 21α). Additionally, the same Kopsia species (K. pauciflora) found in two different geographical locations (Peninsular Malaysia and Malaysian Borneo) showed different patterns in the composition of the enantiomeric eburnane alkaloids. Revision of the absolute configurations of a number of new eburnane congeners (previously assigned based on the assumption of a common biogenetic origin to that of the known eburnane alkaloids co-occurring in the same plant) is required based on the present results.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

Fulltext Antioxidants and α-glucosidase inhibitors from Neptunia oleracea fractions using 1H NMR-based metabolomics approach and UHPLC-MS/MS analysis

Lee SY, Mediani A, Ismail IS, Maulidiani, Abas F

BMC Complement Altern Med, 2019 Jan 07;19(1):7.

PMID: 30616569 DOI: 10.1186/s12906-018-2413-4

BACKGROUND: Neptunia oleracea is a plant cultivated as vegetable in Southeast Asia. Previous works have revealed the potential of this plant as a source of natural antioxidants and α-glucosidase inhibitors. Continuing our interest on this plant, the present work is focused in identification of the bioactive compounds from different polarity fractions of N. oleracea, namely hexane (HF), chloroform (CF), ethyl acetate (EF) and methanol (MF).

METHODS: The N. oleracea fractions were obtained using solid phase extraction (SPE). A metabolomics approach that coupled the use of proton nuclear magnetic resonance (1H NMR) with multivariate data analysis (MVDA) was applied to distinguish the metabolite variations among the N. oleracea fractions, as well as to assess the correlation between metabolite variation and the studied bioactivities (DPPH free radical scavenging and α-glucosidase inhibitory activities). The bioactive fractions were then subjected to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis to profile and identify the potential bioactive constituents.

RESULTS: The principal component analysis (PCA) discriminated EF and MF from the other fractions with the higher distributions of phenolics. Partial least squares (PLS) analysis revealed a strong correlation between the phenolics and the studied bioactivities in the EF and the MF. The UHPLC-MS/MS profiling of EF and MF had tentatively identified the phenolics present. Together with some non-phenolic metabolites, a total of 37 metabolites were tentatively assigned.

CONCLUSIONS: The findings of this work supported that N. oleracea is a rich source of phenolics that can be potential antioxidants and α-glucosidase inhibitors for the management of diabetes. To our knowledge, this study is the first report on the metabolite-bioactivity correlation and UHPLC-MS/MS analysis of N. oleracea fractions.

Matched MeSH terms: Nuclear Magnetic Resonance, Biomolecular

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