Displaying all 11 publications

Abstract:
Sort:
  1. Prakash I, Bunders C, Devkota KP, Charan RD, Ramirez C, Snyder TM, et al.
    Molecules, 2014 Oct 28;19(11):17345-55.
    PMID: 25353385 DOI: 10.3390/molecules191117345
    To supply the increasing demand of natural high potency sweeteners to reduce the calories in food and beverages, we have looked to steviol glycosides. In this work we report the bioconversion of rebaudioside A to rebaudioside I using a glucosyltransferase enzyme. This bioconversion reaction adds one sugar unit with a 1→3 linkage. We utilized 1D and 2D NMR spectroscopy (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY and NOESY) and mass spectral data to fully characterize rebaudioside I.
    Matched MeSH terms: Glucosides/metabolism
  2. Rengasamy N, Othman RY, Che HS, Harikrishna JA
    J Sci Food Agric, 2022 Jan 15;102(1):299-311.
    PMID: 34091912 DOI: 10.1002/jsfa.11359
    BACKGROUND: Stevia rebaudiana is a high value crop due to the strong commercial demand for its metabolites (steviol glycosides) but has limited geographical cultivation range. In non-native environments with different daylength and light quality, Stevia has low germination rates and early flowering resulting in lower biomass and poor yield of the desired metabolites. In this study, artificial lighting with light-emitting diodes (LEDs) was used to determine if different light quality within and outside of the photosynthetically active radiation (PAR) range can be used to improve germination rates and yields for production of steviol glycosides for the herbal supplement and food industry.

    RESULTS: Plants treated with red and blue light at an intensity of 130 μmol m-2  s-1 supplemented with 5% of UV-A light under a 16-h photoperiod produced the most desirable overall results with a high rate of germination, low percentage of early flowering, and high yields of dry leaf, stevioside and rebaudioside A, 175 days after planting.

    CONCLUSION: While red and blue light combinations are effective for plant growth, the use of supplemental non-PAR irradiation of UV-A wavelength significantly and desirably delayed flowering, enhanced germination, biomass, rebaudioside A and stevioside yields, while supplemental green light improved yield of biomass and rebaudioside A, but not stevioside. Overall, the combination of red, blue and UV-A light resulted in the best overall productivity for Stevia rebaudiana. © 2021 Society of Chemical Industry.

    Matched MeSH terms: Glucosides/metabolism
  3. Hussain RMF, Kim HK, Khurshid M, Akhtar MT, Linthorst HJM
    Metabolomics, 2018 01 31;14(3):25.
    PMID: 30830336 DOI: 10.1007/s11306-018-1317-0
    INTRODUCTION: WRKY proteins belong to a plant-specific class of transcription factors. Seventy-four WKRY genes have been identified in Arabidopsis and many WRKY proteins are known to be involved in responses to stress, especially to biotic stress. They may act either as transcriptional activators or as repressors of genes that play roles in the stress response. A number of studies have proposed the connection of Arabidopsis WRKY transcription factors in induced pathogenesis-related (PR) gene expression, although no direct evidence has been presented for specific WRKY-PR promoter interactions.

    OBJECTIVE: We previously identified AtWRKY50 as a transcriptional activator of SAR gene PR1. Although PR1 accumulates to high levels in plants after attack by pathogens, its function is still elusive. Here we investigated the effects of overexpression of several WRKY proteins, including AtWRKY50, on the metabolome of Arabidopsis thaliana.

    METHODS: The influence of overexpression of WRKY proteins on the metabolites of Arabidopsis was investigated by using an NMR spectroscopy-based metabolomic approach. The 1H NMR data was analysed using the multivariate data analysis methods, such as principal component analysis, hierarchical cluster analysis and partial least square-discriminant analysis.

    RESULTS: The results showed that the metabolome of transgenic Arabidopsis seedlings overexpressing AtWRKY50 was different from wild type Arabidopsis and transgenic Arabidopsis overexpressing other WRKY genes. Amongst other metabolites, sinapic acid and 1-O-sinapoyl-β-D-glucose especially appeared to be the most prominent discriminating metabolites, accumulating to levels 2 to 3 times higher in the AtWRKY50 overexpressor lines.

    CONCLUSION: Our results indicate a possible involvement of AtWRKY50 in secondary metabolite production in Arabidopsis, in particular of hydroxycinnamates such as sinapic acid and 1-O-sinapoyl-β-D-glucose.

    Matched MeSH terms: Glucosides/metabolism*
  4. Yeo SK, Liong MT
    J Sci Food Agric, 2013 Jan;93(2):396-409.
    PMID: 22806322 DOI: 10.1002/jsfa.5775
    The aim of this study was to evaluate the effect of electroporation (2.5-7.5 kV cm⁻¹ for 3.0-4.0 ms) on the growth of lactobacilli and bifidobacteria, membrane properties and bioconversion of isoflavones in mannitol-soymilk.
    Matched MeSH terms: Glucosides/metabolism
  5. Ewe JA, Wan-Abdullah WN, Alias AK, Liong MT
    Int J Food Sci Nutr, 2012 Aug;63(5):580-96.
    PMID: 22149599 DOI: 10.3109/09637486.2011.641940
    This study aimed at utilizing electroporation to further enhance the growth of lactobacilli and their isoflavone bioconversion activities in biotin-supplemented soymilk. Strains of lactobacilli were treated with different pulsed electric field strength (2.5, 5.0 and 7.5 kV/cm) for 3, 3.5 and 4 ms prior to inoculation and fermentation in biotin-soymilk at 37°C for 24 h. Electroporation triggered structural changes within the cellular membrane of lactobacilli that caused lipid peroxidation (p 9 log CFU/ml after fermentation in biotin-soymilk (p 
    Matched MeSH terms: Glucosides/metabolism
  6. Yeo SK, Liong MT
    Int J Food Sci Nutr, 2012 Aug;63(5):566-79.
    PMID: 22133079 DOI: 10.3109/09637486.2011.639349
    The aim of this study was to evaluate the effects of ultraviolet (UV) radiation (ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC) at 30-90 J/m²) on the membrane properties of lactobacilli and bifidobacteria, and their bioconversion of isoflavones in prebiotic-soymilk. UV treatment caused membrane permeabilization and alteration at the acyl chain, polar head and interface region of membrane bilayers via lipid peroxidation. Such alteration subsequently led to decreased (p < 0.05) viability of lactobacilli and bifidobacteria immediately after the treatment. However, the effect was transient where cells treated with UV, particularly UVA, grew better in prebiotic-soymilk than the control upon fermentation at 37°C for 24 h (p < 0.05). In addition, UV treatment also increased (p < 0.05) the intracellular and extracellular β-glucosidase activity of lactobacilli and bifidobacteria. This was accompanied by an increased (p < 0.05) bioconversion of glucosides to bioactive aglycones in prebiotic-soymilk. Our present study illustrated that treatment of lactobacilli and bifidobacteria with UV could develop a fermented prebiotic-soymilk with enhanced bioactivity.
    Matched MeSH terms: Glucosides/metabolism
  7. Yeo SK, Liong MT
    Int J Food Sci Nutr, 2010 Mar;61(2):161-81.
    PMID: 20085504 DOI: 10.3109/09637480903348122
    Lactobacillus sp. FTDC 2113, L. acidophilus FTDC 8033, L. acidophilus ATCC 4356, L. casei ATCC 393, Bifidobacterium FTDC 8943 and B. longum FTDC 8643 were incorporated into soymilk supplemented with fructooligosaccharides (FOS), inulin, mannitol, maltodextrin and pectin. The objective of the present study was to evaluate the effects of prebiotics on the bioactivity of probiotic-fermented soymilk. Proteolytic activity was increased in the presence of FOS, while the supplementation of inulin and pectin increased the angiotensin I-converting enzyme inhibitory activity accompanied by lower IC(50) values. The beta-glucosidase activity was also enhanced in the presence of pectin. This led to higher bioconversion of glucosides to aglycones by probiotics, especially genistin and malonyl genistin to genistein. Results from this study indicated that the supplementation of prebiotics enhanced the in-vitro antihypertensive effect and production of bioactive aglycones in probiotic-fermented soymilk. Therefore, this soymilk could potentially be used as a dietary therapy to reduce the risks of hypertension and hormone-dependent diseases such as breast cancer, prostate cancer and osteoporosis.
    Matched MeSH terms: Glucosides/metabolism
  8. Elendran S, Muniyandy S, Lee WW, Palanisamy UD
    Food Funct, 2019 Feb 20;10(2):602-615.
    PMID: 30566155 DOI: 10.1039/c8fo01927d
    Ellagitannins, found abundantly in berries, pomegranates, walnuts and almonds, have been increasingly investigated for their health benefits. Geraniin (GE), an ellagitannin, found predominantly in herbal plants, as well has been shown to exhibit a number of biological activities. Like many hydrolysable tannins, geraniin is water-soluble and readily undergoes hydrolysis in the presence of hot water, weak acids and weak bases to yield several metabolites including corilagin (CO), ellagic acid (EA) and gallic acid (GA). There are numerous studies on the pharmacological effectiveness of GE, CO and GA. However, the intestinal permeability of GE and CO has never been investigated before. Caco-2 cell transport assay was utilized to evaluate the in vitro permeability of GE and its metabolites. GE, CO and EA were found to have no apparent permeability (Papp) while GA displayed a Papp value of 31.3 ± 1.1 × 10-6 cm s-1. Mass balance studies showed a loss of geraniin and its metabolites during transport. Chemical stability studies in the transport buffers revealed that GE and CO were hydrolyzed in the HBSS buffers. Experiments using lysed cells revealed that GE and its metabolites were metabolized during transport. Absorption and desorption studies confirmed the accumulation of EA inside the cells. The above results indicate that the compounds have poor oral absorption. To consider these compounds or their natural extracts as oral nutraceutical candidates, formulation strategies are mandatory.
    Matched MeSH terms: Glucosides/metabolism*
  9. Looi D, Goh BH, Khan SU, Ahemad N, Palanisamy UD
    Int J Food Sci Nutr, 2021 Jun;72(4):470-477.
    PMID: 33032478 DOI: 10.1080/09637486.2020.1830263
    Hypertension is defined as the persistence of elevated blood pressure in the circulation system. The renin-angiotensin-aldosterone system is a major modulator of blood pressure. Among the risk factors of cardiovascular disease, hypertension is the most preventable and treatable, with drugs such as ACE inhibitors. Many ACE inhibitors are known to have undesirable side effects and hence, natural alternatives are being sought. Dietary polyphenols, particularly ellagitannins, are derived from plant products and are known to exhibit a variety of bioactivities. Geraniin, an ellagitannin has been shown to have antihypertensive activity in animal experiments. It is speculated that the metabolites of geraniin are responsible for its ACE inhibitory activity. We have performed in vitro ACE inhibition and in silico studies with geraniin and its metabolites (ellagic acid, urolithins). Our studies confirm that ellagic acid exhibited similar inhibitory potential to ACE as the positive control captopril.
    Matched MeSH terms: Glucosides/metabolism*
  10. Valdiani A, Talei D, Tan SG, Abdul Kadir M, Maziah M, Rafii MY, et al.
    PLoS One, 2014;9(2):e87034.
    PMID: 24586262 DOI: 10.1371/journal.pone.0087034
    Andrographolides, the diterpene lactones, are major bioactive phytochemicals which could be found in different parts of the medicinal herb Andrographis paniculata. A number of such compounds namely andrographolide (AG), neoandrographolide (NAG), and 14-deoxy-11,12-didehydroandrographolide (DDAG) have already attracted a great deal of attention due to their potential therapeutic effects in hard-to-treat diseases such as cancers and HIV. Recently, they have also been considered as substrates for the discovery of novel pharmaceutical compounds. Nevertheless, there is still a huge gap in knowledge on the genetic pattern of the biosynthesis of these bioactive compounds. Hence, the present study aimed to investigate the genetic mechanisms controlling the biosynthesis of these phytochemicals using a diallel analysis. The high performance liquid chromatography analysis of the three andrographolides in 210 F1 progenies confirmed that the biosynthesis of these andrographolides was considerably increased via intraspecific hybridization. The results revealed high, moderate and low heterosis for DDAG, AG and NAG, respectively. Furthermore, the preponderance of non-additive gene actions was affirmed in the enhancement of the three andrographolides contents. The consequence of this type of gene action was the occurrence of high broad-sense and low narrow-sense heritabilities for the above mentioned andrographolides. The prevalence of non-additive gene action suggests the suitability of heterosis breeding and hybrid seed production as a preferred option to produce new plant varieties with higher andrographolide contents using the wild accessions of A. paniculata. Moreover, from an evolutionary point of view, the occurrence of population bottlenecks in the Malaysian accessions of A. paniculata was unveiled by observing a low level of additive genetic variance (VA ) for all the andrographolides.
    Matched MeSH terms: Glucosides/metabolism
  11. Abdul Ahmad SA, Palanisamy UD, Tejo BA, Chew MF, Tham HW, Syed Hassan S
    Virol J, 2017 11 21;14(1):229.
    PMID: 29162124 DOI: 10.1186/s12985-017-0895-1
    BACKGROUND: The rapid rise and spread in dengue cases, together with the unavailability of safe vaccines and effective antiviral drugs, warrant the need to discover and develop novel anti-dengue treatments. In this study the antiviral activity of geraniin, extracted from the rind of Nephelium lappaceum, against dengue virus type-2 (DENV-2) was investigated.

    METHODS: Geraniin was prepared from Nephelium lappaceum rind by reverse phase C-18 column chromatography. Cytotoxicity of geraniin towards Vero cells was evaluated using MTT assay while IC50 value was determined by plaque reduction assay. The mode-of-action of geraniin was characterized using the virucidal, attachment, penetration and the time-of-addition assays'. Docking experiments with geraniin molecule and the DENV envelope (E) protein was also performed. Finally, recombinant E Domain III (rE-DIII) protein was produced to physiologically test the binding of geraniin to DENV-2 E-DIII protein, through ELISA competitive binding assay.

    RESULTS: Cytotoxicity assay confirmed that geraniin was not toxic to Vero cells, even at the highest concentration tested. The compound exhibited DENV-2 plaque formation inhibition, with an IC50 of 1.75 μM. We further revealed that geraniin reduced viral infectivity and inhibited DENV-2 from attaching to the cells but had little effect on its penetration. Geraniin was observed to be most effective when added at the early stage of DENV-2 infection. Docking experiments showed that geraniin binds to DENV E protein, specifically at the DIII region, while the ELISA competitive binding assay confirmed geraniin's interaction with rE-DIII with high affinity.

    CONCLUSIONS: Geraniin from the rind of Nephelium lappaceum has antiviral activity against DENV-2. It is postulated that the compound inhibits viral attachment by binding to the E-DIII protein and interferes with the initial cell-virus interaction. Our results demonstrate that geraniin has the potential to be developed into an effective antiviral treatment, particularly for early phase dengue viral infection.

    Matched MeSH terms: Glucosides/metabolism*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links