Displaying publications 1 - 20 of 508 in total

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  1. Rosli SZ, Mohd Adzahan N, Karim R, Mahmud Ab Rashid NK
    Molecules, 2022 Dec 30;28(1).
    PMID: 36615505 DOI: 10.3390/molecules28010311
    Pennywort (Centella asiatica) is a herbaceous vegetable that is usually served in the form of fresh-cut vegetables and consumed raw. Fresh-cut vegetables are in high demand as they offer convenience, have fresh-like quality and are potentially great for therapeutic applications. However, it could be the cause of foodborne outbreaks. Pulsed light is known as a decontamination method for minimally processed products. The aim of this study was to determine the influence of pulsed light in combination with acidic electrolysed water on the sensory, morphological changes and bioactive components in the leaves of pennywort during storage. A combination of soaking with acidic electrolysed water (AEW) at pH 2.5 and pulsed light (PL) treatment (1.5 J/cm2) was tested on the leaves of pennywort. After treatment, these leaves were refrigerated (4 ± 1 °C) for two weeks and evaluated on the basis of sensory acceptance, the visual appearance of the epidermal cell and bioactive compounds. In terms of sensorial properties, samples treated with the combined treatment were preferred over untreated samples. The combination of AEW and PL 1.5 J/cm2 was the most preferred in terms of purchasing and consumption criteria. Observations of the epidermal cells illustrated that PL treatment kept the cell structure intact. The bioactive phytocompounds found in the leaves of pennywort are mainly from the triterpene glycosides (asiaticoside, madecassoside, asiatic acid and madecassic acid) and are efficiently preserved by the combined treatment applied. In conclusion, the combination of acidic electrolysed water and pulsed light treatment is beneficial in retaining the sensory quality and bioactive compounds in the leaves of Pennywort during storage at 4 ± 1 °C.
    Matched MeSH terms: Plant Leaves/chemistry
  2. Sirat HM, Jani NA
    Nat Prod Res, 2013;27(16):1468-70.
    PMID: 22946537 DOI: 10.1080/14786419.2012.718772
    Hydrodistillation of the fresh leaves of Alpinia mutica afforded 0.005% colourless essential oil. GC and GC-MS analysis revealed the presence of 33 components accounting for 92.9% of the total oil, dominated by 20 sesquiterpenes (76.7%) and 10 monoterpenes (8.3%). The major constituent was found to be β-sesquiphellandrene which was 29.2% of the total oil. Soxhlet extraction, followed by repeated column chromatography of the dried leaves yielded two phenolic compounds, identified as 5,6-dehydrokawain and aniba dimer A, together with one amide assigned as auranamide. The structures of these compounds were determined by using spectroscopic analysis. Antibacterial screening of the essential oil, the crude and isolated compounds showed weak to moderate inhibitory activity.
    Matched MeSH terms: Plant Leaves/chemistry*
  3. Starkenmann C, Luca L, Niclass Y, Praz E, Roguet D
    J Agric Food Chem, 2006 Apr 19;54(8):3067-71.
    PMID: 16608232
    Polygonum odoratum Lour. has been reclassified as Persicaria odorata (Lour.) Soják [Wilson, K. L. Polygonum sensu lato (Polygonaceae) in Australia. Telopea 1988, 3, 177-182]; other synonyms currently used are Vietnamese mint or Vietnamese coriander and, in Malaysia, Daun Laksa or Laksa plant. The aerial parts of Laksa plant are highly aromatic, and they contain many organic compounds such as (Z)-3-hexenal, (Z)-3-hexenol, decanal, undecanal, and dodecanal that are typical for green, citrus, orange peel, and coriander odors. In addition to these aldehydes, 3-sulfanyl-hexanal and 3-sulfanyl-hexan-1-ol were discovered for the first time in this herb. The fresh leaves are pungent when they are chewed, although the active compound has never been identified. The pungency of Persicaria hydropiper (L.) Spach (formerly Polygonum hydropiper L., synonym water pepper) is produced by polygodial, a 1,4-dialdehyde derived from drimane terpenoids. We also identified polygodial as the active pungent compound in P. odorata (Lour.) Soják.
    Matched MeSH terms: Plant Leaves/chemistry
  4. Wah LK, Abas F, Cordell GA, Ito H, Ismail IS
    Steroids, 2013 Feb;78(2):210-9.
    PMID: 23178158 DOI: 10.1016/j.steroids.2012.09.011
    Seven new 23-oxo-cholestane derivatives named as grandol A (1), B (2), C (3), D (4), E (5), F (6), and G (7) were isolated from Dysoxylum grande leaves alongside with a new 3,4-secodammar-4(28)-en-3-oic acid derivative (8). The structures of the compounds were elucidated based on the interpretation of spectroscopic data, and their relative configurations were established by NOESY 2D NMR data. All of the isolates were tested for anti-acetylcholinesterase activity using thin layer chromatography (TLC)-bioautography with fast blue B salt. Only grandol A (1) and B (2) showed positive results, with clear discoloration at a concentration of 12.5 ppm. However, the obtained IC(50) values for grandol A and B, when using Ellman's method, were not significant (>200 μg/ml).
    Matched MeSH terms: Plant Leaves/chemistry*
  5. Aung HH, Chia LS, Goh NK, Chia TF, Ahmed AA, Pare PW, et al.
    Fitoterapia, 2002 Aug;73(5):445-7.
    PMID: 12165348
    Plumbagin, isoshinanolone, epishinanolone, shinanolone, quercetin and kaempferol were isolated from the leaves of Nepenthes gracilis. Spectral data of shinanolone are presented.
    Matched MeSH terms: Plant Leaves/chemistry
  6. Farag MA, Elmetwally F, Elghanam R, Kamal N, Hellal K, Hamezah HS, et al.
    Food Chem, 2023 Mar 15;404(Pt B):134628.
    PMID: 36283313 DOI: 10.1016/j.foodchem.2022.134628
    Tea is one of the world's most popular beverages, with several health benefits. Polyphenols are the predominant constituents to account for its health benefits. Despite the well-known benefits of tea on health, the uniqueness of its aroma, taste, and features is an added value that contribute to the increased popularity of this beverage worldwide, and they are associated with the alterations in the metabolites during tea processing and cultivation. The manufacturing of tea consists of several stages with various processes as withering, fixing, rolling, fermentation and drying. The classification into tea types is according to such processing. The high-quality production of the various tea classes also depends on agricultural conditions, such as shading, plucking, climate, and soil composition. Metabolomics is well recognized as an effective tool for evaluating the quality of tea products. Applications in controlling the quality of tea products and adulterant detection are discussed in this review.
    Matched MeSH terms: Plant Leaves/chemistry
  7. Ahmad A, Abdullah SRS, Hasan HA, Othman AR, Ismail N'
    Environ Sci Pollut Res Int, 2022 Jan;29(2):2579-2587.
    PMID: 34374006 DOI: 10.1007/s11356-021-15541-7
    The performance of local plants was tested using synthetic turbid water resembling real wastewater by measuring their ability to remove turbidity. The selected plants were A. indica, S. palustris, D. linearis, S. polyanthum, M. esculenta, P. sarmentosum, and M. malabathricum which can easily be found locally. The experiment was run based on coagulant dosages varied from 0 to 10 g/L for each plant with a rapid mixing speed at 180 rpm for 3 min, slow mixing speed at 10 rpm for 20 min, and settling time for 30 min. The results demonstrated that each plant has been capable of reducing turbidity by different amounts, with an increase in the coagulant dosage. The optimum coagulant dosages achieved for A. indica, S. palustris, S. polyanthum, and D. linearis were 10 g/L with turbidity removal at 26.9%, 24.9%, 24.9%, and 17.5%, respectively. P. sarmentosum and M. esculenta attained optimum coagulant dosages at 5 g/L with turbidity removal at 24.2% and 22.2%, and lastly M. malabathricum at 0.1 g/L (12.2%). P. sarmentosum was suggested to the best natural coagulant which achieved the highest removal of turbidity with a low dosage used.
    Matched MeSH terms: Plant Leaves/chemistry
  8. Mussa ZH, Al-Ameer LR, Al-Qaim FF, Deyab IF, Kamyab H, Chelliapan S
    Environ Monit Assess, 2023 Jul 12;195(8):940.
    PMID: 37436672 DOI: 10.1007/s10661-023-11432-1
    Water bodies with the dye methylene blue pose serious environmental and health risks to humans. Therefore, the creation and investigation of affordable, potential adsorbents to remove methylene blue dye from water resources as a long-term fix is one focus of the scientific community. Food plants and other carbon-source serve as a hotspot for a wider range of application on different pollutants that impact the environment and living organisms. Here, we reviewed the use of treated and untreated biosorbents made from plant waste leaves for removing the dye methylene blue from aqueous media. After being modified, activated carbon made from various plant leaves improves adsorption performance. The range of activating chemicals, activation methods, and bio-sorbent material characterisation using FTIR analysis, Barunauer-Emmett-Teller (BET) surface area, scanning electron microscope (SEM-EDX), and SEM-EDX have all been covered in this review. It has been thoroughly described how the pH solution of the methylene blue dye compares to the pHPZC of the adsorbent surface. The presentation also includes a thorough analysis of the application of the isotherm model, kinetic model, and thermodynamic parameters. The selectivity of the adsorbent is the main focus of the adsorption kinetics and isotherm models. It has been studied how adsorption occurs, how surface area and pH affect it, and how biomass waste compares to other adsorbents. The use of biomass waste as adsorbents is both environmentally and economically advantageous, and it has been discovered to have exceptional color removal capabilities.
    Matched MeSH terms: Plant Leaves/chemistry
  9. Mahmud K, Weitz H, H Kritzler U, Burslem DFRP
    PLoS One, 2024;19(3):e0297686.
    PMID: 38507439 DOI: 10.1371/journal.pone.0297686
    Aluminium (Al) is toxic to most plants, but recent research has suggested that Al addition may stimulate growth and nutrient uptake in some species capable of accumulating high tissue Al concentrations. The physiological basis of this growth response is unknown, but it may be associated with processes linked to the regulation of carbon assimilation and partitioning by Al supply. To test alternative hypotheses for the physiological mechanism explaining this response, we examined the effects of increasing Al concentrations in the growth medium on tissue nutrient concentrations and carbon assimilation in two populations of the Al-accumulator Melastoma malabathricum. Compared to seedlings grown in a control nutrient solution containing no Al, mean rates of photosynthesis and respiration increased by 46% and 27%, respectively, total non-structural carbohydrate concentrations increased by 45%, and lignin concentration in roots decreased by 26% when seedlings were grown in a nutrient solution containing 2.0 mM Al. The concentrations of P, Ca and Mg in leaves and stems increased by 31%, 22%, and 26%, respectively, in response to an increase in nutrient solution Al concentration from 0 to 2.0 mM. Elemental concentrations in roots increased for P (114%), Mg (61%) and K (5%) in response to this increase in Al concentration in the nutrient solution. Plants derived from an inherently faster-growing population had a greater relative increase in final dry mass, net photosynthetic and respiration rates and total non-structural carbohydrate concentrations in response to higher external Al supply. We conclude that growth stimulation by Al supply is associated with increases in photosynthetic and respiration rates and enhanced production of non-structural carbohydrates that are differentially allocated to roots, as well as stimulation of nutrient uptake. These responses suggest that internal carbon assimilation is up-regulated to provide the necessary resources of non-structural carbohydrates for uptake, transport and storage of Al in Melastoma malabathricum. This physiological mechanism has only been recorded previously in one other plant species, Camellia sinensis, which last shared a common ancestor with M. malabathricum more than 120 million years ago.
    Matched MeSH terms: Plant Leaves/chemistry
  10. Ong P, Jian J, Li X, Zou C, Yin J, Ma G
    PMID: 39180971 DOI: 10.1016/j.saa.2024.125001
    Utilizing visible and near-infrared (Vis-NIR) spectroscopy in conjunction with chemometrics methods has been widespread for identifying plant diseases. However, a key obstacle involves the extraction of relevant spectral characteristics. This study aimed to enhance sugarcane disease recognition by combining convolutional neural network (CNN) with continuous wavelet transform (CWT) spectrograms for spectral features extraction within the Vis-NIR spectra (380-1400 nm) to improve the accuracy of sugarcane diseases recognition. Using 130 sugarcane leaf samples, the obtained one-dimensional CWT coefficients from Vis-NIR spectra were transformed into two-dimensional spectrograms. Employing CNN, spectrogram features were extracted and incorporated into decision tree, K-nearest neighbour, partial least squares discriminant analysis, and random forest (RF) calibration models. The RF model, integrating spectrogram-derived features, demonstrated the best performance with an average precision of 0.9111, sensitivity of 0.9733, specificity of 0.9791, and accuracy of 0.9487. This study may offer a non-destructive, rapid, and accurate means to detect sugarcane diseases, enabling farmers to receive timely and actionable insights on the crops' health, thus minimizing crop loss and optimizing yields.
    Matched MeSH terms: Plant Leaves/chemistry
  11. 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: Plant Leaves/chemistry
  12. Jani NA, Sirat MH, Ali NM, Aziz A
    Nat Prod Commun, 2013 Apr;8(4):513-4.
    PMID: 23738467
    The chemical compositions of the essential oil of the rhizome, leaf and stem of Hornstedtia leonurus Retz., collected from Negeri Sembilan, Malaysia,are reported for the first time. The essential oils were extracted using hydrodistillation and analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MS). Seventeen (96.4%), thirteen (89.2%) and nine components (98.8%) were successfully identified from the rhizome, stem and leaf oils, respectively. Phenylpropanoids were found to be the major fraction, with methyleugenol being the most abundant compound in all oils with percentage compositions of 76.4% (rhizome), 80.3% (stem) and 74.5% (leaf).
    Matched MeSH terms: Plant Leaves/chemistry
  13. Hussin N, Mondello L, Costa R, Dugo P, Yusoff NI, Yarmo MA, et al.
    Nat Prod Commun, 2012 Jul;7(7):927-30.
    PMID: 22908584
    Patchouli essential oil can be obtained from fresh, dried and fermented plant material. It is a highly valuable product in the fragrance industry and its quality changes depending upon raw material age and oil storage. In this work, patchouli essential oils derived from different treatments have been subjected to GC-FID quantitative analysis using an internal standard (ISTD) method with response factors (RF). Samples were obtained from i) fresh plants; ii) hydrodistillation of one year mature and fermented plants; iii) hydrodistillation of one year mature plants; iv) commercial products from Indonesia and Malaysia. Linear Retention Indices (LRI) for both polar and non-polar GC-MS analyses were also measured as a tool for qualitative analysis towards a homologous series of C7-C30 n-alkanes. The results obtained confirmed that, in all samples, patchouli alcohol was the main volatile constituent, with higher amount in lab-scale produced oils, compared with commercial samples. Other major compounds, in lab oils and commercial samples respectively, were: delta-guaiene, alpha-guaiene, pogostol, seychellene and alpha-patchoulene. Another 36 compounds were also found.
    Matched MeSH terms: Plant Leaves/chemistry
  14. Har LW, Shaari K, Boon LH, Kamarulzaman FA, Ismail IS
    Nat Prod Commun, 2012 Aug;7(8):1033-6.
    PMID: 22978223
    Two new phloroglucinol derivatives, identified as anthuminoate (1) and anthuminone (2), were isolated from the ichthyotoxic ethyl acetate fraction of Syzygium polyanthum leaves. In addition, bioassay-guided fractionation followed by dereplication of the photocytotoxic fraction of this plant part has resulted in the identification of five known pheophorbides as the bioactive constituents. The compounds were identified as pheophorbide-a, methyl pheophorbide-a, methyl hydroxypheophorbide-a, pheophorbide-b and hydroxypheophorbide-b. Inhibition of cell viability shown by the compounds ranged from 83.3 to 86.1% at a test concentration of 5 microg/mL. This shows that Syzygium polyanthum leaves are a potential new source in the studies of photocytotoxicity for photodynamic therapy.
    Matched MeSH terms: Plant Leaves/chemistry*
  15. Hossain MA, Shah MD, Gnanaraj C, Iqbal M
    Asian Pac J Trop Med, 2011 Sep;4(9):717-21.
    PMID: 21967695 DOI: 10.1016/S1995-7645(11)60180-6
    OBJECTIVE: To detect the in vitro total phenolics, flavonoids contents and antioxidant activity of essential oil, various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.

    METHODS: The dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane, ethyl acetate, chloroform, butanol and aqueous methanol. The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane, ethyl acetate, chloroform, butanol and aqueous ethanol were determined by Folin - Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity using α, α-diphenyl- β-picrylhydrazyl (DPPH) method.

    RESULTS: The total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract (386.22 mg/g) followed by ethyl acetate (190.89 mg/g), chloroform (175.89 mg/g), hexane (173.44 mg/g), and butanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil. The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract > ethyl acetate extract >chloroform> butanol > hexane extract also the antioxidant activity was not detected in essential oil.

    CONCLUSIONS: The findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract. Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.

    Matched MeSH terms: Plant Leaves/chemistry
  16. Sim KM, Teh HM
    J Asian Nat Prod Res, 2011 Oct;13(10):972-5.
    PMID: 21972815 DOI: 10.1080/10286020.2011.602970
    New carbazole alkaloid, 7-hydroxymurrayazolinine (1), was isolated from the ethanol extract of the leaves of Malayan Murraya koenigii, together with five known carbazole alkaloids, mahanimbine (2), bicyclomahanimbine (3), girinimbine (4), koenimbine (5), and murrayamine-D (6). Their structures were elucidated on the basis of spectroscopic analysis.
    Matched MeSH terms: Plant Leaves/chemistry
  17. Iwashina T, Matsumoto S, Kitajima J, Nakamura T, Kokubugata G, Suleiman M, et al.
    Nat Prod Commun, 2010 Jan;5(1):39-42.
    PMID: 20184017
    Two new flavone rhamnosides, apigenin 7-O-alpha-L-rhamnopyranosyl-(1-->4)-O-alpha-L-rhamnopyranoside and apigenin 7-O-alpha-L-rhamnopyranosyl-(1-->4)-O-alpha-L-rhamnopyranoside-4'-O-alpha-L-rhamnopyranoside were isolated from the fronds of Asplenium normale D. Don, together with two known C-glycosylflavones, vicenin-2 and lucenin-2. The chemical structures of the isolated glycosides were established by UV, LC-MS, characterization of acid hydrolysates, and 1H and 13C NMR spectroscopy.
    Matched MeSH terms: Plant Leaves/chemistry
  18. Awang K, Abdullah Z, Mukhtar MR, Litaudon M, Jaafar FM, Hadi AH, et al.
    Nat Prod Res, 2009;23(7):652-8.
    PMID: 19401920 DOI: 10.1080/14786410802323743
    Dunaliine A (1), a new amino diketone, has been isolated from the leaves of Desmos dunalii together with four known dihydrochalcones: 2',4-dihydroxy-4',6'-dimethoxy-3',5'-dimethyldihydrochalcone (2), 2',4-dihydroxy-4',6'-dimethoxydihydrochalcone (3), 2',4-dihydroxy-4',5',6'-trimethoxydihydrochalcone (4) and 2',4-dihydroxy-5'-methyl-4',6'-dimethoxydihydrochalcone (5). The structures of these compounds were established notably by spectral analysis (1D- and 2D- (1)H, (13)C NMR), UV, IR and HRMS.
    Matched MeSH terms: Plant Leaves/chemistry*
  19. Nagappan T, Ramasamy P, Vairappan CS
    Nat Prod Commun, 2012 Oct;7(10):1375-8.
    PMID: 23157015
    The composition of the essential oils of Murraya koenigii (L.) Spreng, cultivated at six locations in Peninsula Malaysia and Borneo are presented. The oils were obtained from fresh leaves by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS); 61 compounds were identified, of which eleven were present in all the specimens analyzed. The two major volatile metabolites were identified as beta-caryophyllene (16.6-26.6%) and alpha-humulene (15.2-26.7%) along with nine minor compounds identified as beta-elemene (0.3-1.3%), aromadendrene (0.5-1.5%), beta-selinene (3.8-6.5%), spathulenol (0.6-2.7%), caryophyllene oxide (0.7-3.6%), viridiflorol (1.5-5.5%), 2-naphthalenemethanol (0.7-4.8%), trivertal (0.1-1.0%) and juniper camphor (2.6-8.3%). The results suggest that beta-caryophyllene and alpha-humulene could be used as chemotaxonomical markers for Malaysian M. koenigii, hence these specimens could be of the same stock and different from the ones in India, Thailand and China.
    Matched MeSH terms: Plant Leaves/chemistry
  20. Kirton LG
    Ann Trop Med Parasitol, 2005 Oct;99(7):695-714.
    PMID: 16212803
    Citridiol is an extract of the leaves of Corymbia citriodora (Myrtaceae), the lemon eucalyptus, and mostly consists of p-menthane-3,8-diol isomers. The effectiveness of this extract as a repellent against land leeches of the genus Haemadipsa (Haemadipsidae), primarily H. sylvestris, was tested in the laboratory and field, in Peninsular Malaysia. The formulation tested, Mosi-guard Natural spray, contained 40% (w/w) Citridiol in a base of ethanol, water and isopropanol. In the laboratory test, specimens of H. sylvestris that were placed within moist, untreated arenas enclosed by treated paper rings made numerous attempts to cross the rings but were prevented or delayed from crossing over, in a dose-dependent manner. Mortality was high among the leeches that attempted to cross over the paper rings that had been sprayed to saturation point but low among the leeches that attempted to cross over paper rings that had only been partially treated, with a droplet-spray. The field study was carried out using indices that were formulated to reflect the severity of leech attack and the degree of repellency. Heavy or moderate spraying of footwear and trouser legs (tucked into socks) not only gave complete protection against bites by H. sylvestris and H. picta but also provided high enough repellency to keep the treated footwear virtually free of leeches. Even a light spray greatly reduced the numbers of leeches on footwear and delayed their progression toward biting the test subjects, although it failed to prevent bites completely. There was no decline in the repellency of the Citridiol when hourly assessments were made over a 6-h test period in the field. The results of the study show that Citridiol is highly repellent as well as toxic to leeches, and can be effectively used to prevent leech bites in the field.
    Matched MeSH terms: Plant Leaves/chemistry
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