Displaying publications 221 - 240 of 338 in total

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  1. Moharam BA, Jantan I, Jalil J, Shaari K
    Molecules, 2010 Nov 03;15(11):7840-8.
    PMID: 21060292 DOI: 10.3390/molecules15117840
    Phylligenine, together with quebrachitol, stigmasterol and two aporphine alkaloids--oxoputerine and liriodenine--were isolated from the twigs of Mitrephora vulpina C.E.C. Fisch. They were evaluated for their ability to inhibit platelet activating factor (PAF) receptor binding to rabbit platelets using 3H-PAF as a ligand and their antiplatelet aggregation effect in human whole blood induced by arachidonic acid (AA), collagen and adenosine diphosphate (ADP). Of all the compounds tested, phylligenin and quebrachitol exhibited potent and concentration-dependent inhibitory effects on PAF receptor binding, with IC(50) values of 13.1 and 42.2 µM, respectively. The IC(50) value of phylligenin was comparable to that of cedrol (10.2 µM), a potent PAF antagonist. Phylligenin also showed strong dose-dependent inhibitory activity on platelet aggregation induced by AA and ADP.
    Matched MeSH terms: Alkaloids/isolation & purification; Alkaloids/pharmacology
  2. Salim F, Ismail NH, Awang K, Ahmad R
    Molecules, 2011 Aug 04;16(8):6541-8.
    PMID: 21818057 DOI: 10.3390/molecules16086541
    Two new heteroyohimbine-type oxindole alkaloids, rauniticine-allo-oxindole B and rauniticinic-allo acid B, have been successfully isolated from the stems extract of Malaysian Uncaria longiflora var. pteropoda. The structures of the two new alkaloids were determined by spectroscopic analysis.
    Matched MeSH terms: Alkaloids/isolation & purification*; Alkaloids/chemistry
  3. Yap VA, Loong BJ, Ting KN, Loh SH, Yong KT, Low YY, et al.
    Phytochemistry, 2015 Jan;109:96-102.
    PMID: 25468714 DOI: 10.1016/j.phytochem.2014.10.032
    Hispidacine, an 8,4'-oxyneolignan featuring incorporation of an unusual 2-hydroxyethylamine moiety at C-7, and hispiloscine, a phenanthroindolizidine alkaloid, were isolated from the stem-bark and leaves of the Malaysian Ficus hispida Linn. Their structures were established by spectroscopic analysis. Hispidacine induced a moderate vasorelaxant activity in rat isolated aorta, while hispiloscine showed appreciable antiproliferative activities against MDA-MB-231, MCF-7, A549, HCT-116 and MRC-5 cell lines.
    Matched MeSH terms: Alkaloids/isolation & purification; Alkaloids/chemistry*
  4. Johari SA, Mohtar M, Mohammad SA, Sahdan R, Shaameri Z, Hamzah AS, et al.
    Biomed Res Int, 2015;2015:823829.
    PMID: 25710030 DOI: 10.1155/2015/823829
    28 new pyrrolidine types of compounds as analogues for natural polyhydroxy alkaloids of codonopsinine were evaluated for their anti-MRSA activity using MIC and MBC value determination assay against a panel of S. aureus isolates. One pyrrolidine compound, MFM 501, exhibited good inhibitory activity with MIC value of 15.6 to 31.3 μg/mL against 55 S. aureus isolates (43 MRSA and 12 MSSA isolates). The active compound also displayed MBC values between 250 and 500 μg/mL against 58 S. aureus isolates (45 MRSA and 13 MSSA isolates) implying that MFM 501 has a bacteriostatic rather than bactericidal effect against both MRSA and MSSA isolates. In addition, MFM 501 showed no apparent cytotoxicity activity towards three normal cell lines (WRL-68, Vero, and 3T3) with IC50 values of >625 µg/mL. Selectivity index (SI) of MFM 501 gave a value of >10 suggesting that MFM 501 is significant and suitable for further in vivo investigations. These results suggested that synthetically derived intermediate compounds based on natural products may play an important role in the discovery of new anti-infective agents against MRSA.
    Matched MeSH terms: Alkaloids/administration & dosage*; Alkaloids/chemistry
  5. Ilavenil S, Arasu MV, Lee JC, Kim DH, Roh SG, Park HS, et al.
    Phytomedicine, 2014 Apr 15;21(5):758-65.
    PMID: 24369814 DOI: 10.1016/j.phymed.2013.11.007
    Trigonelline is a natural alkaloid mainly found in Trigonella Foenum Graecum (fenugreek) Fabaceae and other edible plants with a variety of medicinal applications. Therefore, we investigated the molecular mechanism of trigonelline (TG) on the inhibition of adipocyte differentiation and lipid accumulation in 3T3-L1 cells. Trigonelline suppressed lipid droplet accumulation in a concentration (75 and 100 μM) dependent manner. Treatment of adipocyte with of TG down regulates the peroxisome proliferator-activated receptor (PPARγ) and CCAAT element binding protein (C/EBP-α) mRNA expression, which leads to further down regulation of other gene such as adiponectin, adipogenin, leptin, resistin and adipocyte fatty acid binding protein (aP2) as compared with respective control cells on 5th and 10th day of differentiation. Further, addition of triognelline along with troglitazone to the adipocyte attenuated the troglitazone effects on PPARγ mediated differentiation and lipid accumulation in 3T3-L1 cells. Trigonelline might compete against troglitazone for its binding to the PPARγ. In addition, adipocyte treated with trigonelline and isoproterenol separately. Isoproterenol, a lipolytic agent which inhibits the fatty acid synthase and GLUT-4 transporter expression via cAMP mediated pathway, we found that similar magnitude response of fatty acid synthase and GLUT-4 transporter expression in trigonelline treated adipocyte. These results suggest that the trigonelline inhibits the adipogenesis by its influences on the expression PPARγ, which leads to subsequent down regulation of PPAR-γ mediated pathway during adipogenesis. Our findings provide key approach to the mechanism underlying the anti-adipogenic activity of trigonelline.
    Matched MeSH terms: Alkaloids/pharmacology; Alkaloids/therapeutic use*
  6. Santhanam RK, Ahmad S, Abas F, Safinar Ismail I, Rukayadi Y, Tayyab Akhtar M, et al.
    Molecules, 2016 May 24;21(6).
    PMID: 27231889 DOI: 10.3390/molecules21060652
    Zanthoxylum rhetsa is an aromatic tree, known vernacularly as "Indian Prickly Ash". It has been predominantly used by Indian tribes for the treatment of many infirmities like diabetes, inflammation, rheumatism, toothache and diarrhea. In this study, we identified major volatile constituents present in different solvent fractions of Z. rhetsa bark using GC-MS analysis and isolated two tetrahydrofuran lignans (yangambin and kobusin), a berberine alkaloid (columbamine) and a triterpenoid (lupeol) from the bioactive chloroform fraction. The solvent fractions and purified compounds were tested for their cytotoxic potential against human dermal fibroblasts (HDF) and mouse melanoma (B16-F10) cells, using the MTT assay. All the solvent fractions and purified compounds were found to be non-cytotoxic to HDF cells. However, the chloroform fraction and kobusin exhibited cytotoxic effect against B16-F10 melanoma cells. The presence of bioactive lignans and alkaloids were suggested to be responsible for the cytotoxic property of Z. rhetsa bark against B16-F10 cells.
    Matched MeSH terms: Alkaloids/administration & dosage*; Alkaloids/chemistry
  7. Nge CE, Chong KW, Thomas NF, Lim SH, Low YY, Kam TS
    J Nat Prod, 2016 05 27;79(5):1388-99.
    PMID: 27077800 DOI: 10.1021/acs.jnatprod.6b00129
    Ten new indole alkaloids (1-10) comprising five ibogan, two aspidosperman, one vincamine, and two bisindole alkaloids, in addition to 32 known alkaloids, were isolated from the stem-bark extract of a Malayan Tabernaemontana corymbosa. The structures of these alkaloids were determined based on analysis of the NMR and MS data and, in five instances (1, 3, 5, 6, 8), confirmed by X-ray diffraction analysis. Two of the iboga alkaloids, conodusines B (2) and C (3), and the iboga-containing bisindole tabernamidine B (10) are notable for the presence of an α-substituted acetyl group at C-20 of the iboga carbon skeleton. The iboga alkaloid (+)-conodusine E (5) had MS and NMR data that were identical to those of (-)-ervatamine I, recently isolated from Ervatamia hainanensis. Establishment of the absolute configuration of (+)-conodusine E (5) was based on analysis of the ECD data, correlation with (-)-heyneanine, and X-ray analysis, which showed that (+)-5 belongs to the same enantiomeric series as exemplified by (-)-coronaridine. The configuration at C-20' of the previously reported Tabernaemontana bisindole alkaloid 19'-oxotabernamine (renamed tabernamidine B) required revision based on the present results. Several of the bisindoles showed pronounced in vitro growth inhibitory activity against drug-sensitive and vincristine-resistant KB cells.
    Matched MeSH terms: Indole Alkaloids/isolation & purification*; Indole Alkaloids/chemistry*
  8. Zunjar V, Dash RP, Jivrajani M, Trivedi B, Nivsarkar M
    J Ethnopharmacol, 2016 Apr 02;181:20-5.
    PMID: 26812680 DOI: 10.1016/j.jep.2016.01.035
    ETHNOPHARMACOLOGICAL RELAVANCE: The decoction of Carica papaya Linn. leaves is used in folklore medicine in certain parts of Malaysia and Indonesia for the treatment of different types of thrombocytopenia associated with diseases and drugs. There are several scientific studies carried out on humans and animal models to confirm the efficacy of decoction of papaya leave for the treatment of disease induced and drug induced thrombocytopenia, however very little is known about the bio-active compounds responsible for the observed activity. The aim of present study was to identify the active phytochemical component of Carica papaya Linn. leaves decoction responsible for anti-thrombocytopenic activity in busulfan-induced thrombocytopenic rats.

    MATERIALS AND METHODS: Antithrombocytopenic activity was assessed on busulfan induced thrombocytopenic Wistar rats. The antithrombocytopenic activity of different bio-guided fractions was evaluated by monitoring blood platelet count. Bioactive compound carpaine was isolated and purified by chromatographic methods and confirmed by spectroscopic methods (LC-MS and 1D/2D-1H/13C NMR) and the structure was confirmed by single crystal X-ray diffraction. Quantification of carpaine was carried out by LC-MS/MS equipped with XTerra(®) MS C18 column and ESI-MS detector using 90:10 CH3CN:CH3COONH4 (6mM) under isocratic conditions and detected with multiple reaction monitoring (MRM) in positive ion mode.

    RESULTS: Two different phytochemical groups were isolated from decoction of Carica papaya leaves: phenolics, and alkaloids. Out of these, only alkaloid fraction showed good biological activity. Carpaine was isolated from the alkaloid fraction and exhibited potent activity in sustaining platelet counts upto 555.50±85.17×10(9)/L with no acute toxicity.

    CONCLUSIONS: This study scientifically validates the popular usage of decoction of Carica papaya leaves and it also proves that alkaloids particularly carpaine present in the leaves to be responsible for the antithrombocytopenic activity.

    Matched MeSH terms: Alkaloids/pharmacology; Alkaloids/chemistry*
  9. Thomas A, Rajesh EK, Kumar DS
    Phytother Res, 2016 Mar;30(3):357-66.
    PMID: 26749336 DOI: 10.1002/ptr.5559
    Tinospora crispa is a medicinal plant belonging to the botanical family Menispermiaceae. The plant is widely distributed in Southeast Asia and the northeastern region of India. A related species Tinospora cordifolia is used in Ayurveda for treating a large spectrum of diseases. Traditional healers of Thailand, Malaysia, Guyana, Bangladesh and the southern Indian province of Kerala use this plant in the treatment of diabetes. Many diterpenes, triterpenes, phytosteroids, alkaloids and their glycosides have been isolated from T. crispa. Cell culture and animal studies suggest that the herb stimulates secretion of insulin from β-cells. It also causes dose-dependent and time-dependent enhancement of glucose uptake in muscles. However, in view of the reported hepatotoxicity, this herb may be used with caution. This article reviews the animal studies and human clinical trials carried out using this herb. Areas of future research are also identified.
    Matched MeSH terms: Alkaloids/pharmacology; Alkaloids/therapeutic use
  10. Kong WM, Mohamed Z, Alshawsh MA, Chik Z
    J Pharm Biomed Anal, 2017 Sep 05;143:43-47.
    PMID: 28551311 DOI: 10.1016/j.jpba.2017.05.020
    A microdialysis system coupled with a sensitive ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) method was developed for the pharmacokinetic analysis of mitragynine in rat blood and striatum. Mitragynine is an active alkaloid of Mitragyna speciosa and has been proposed to be used for opioid withdrawal therapy. In this study, chromatographic separation was performed in a gradient elution mode with 0.1% formic acid and acetonitrile on a Zorbax Eclipse C18 column. The mass spectrometric (MS) analysis was carried out in a positive electrospray mode and mitragynine ion (m/z 399.2) was monitored in extracted ion chromatography. A good linearity range was obtained from 10-1000ng/mL with acceptable accuracy and precision parameters. The microdialysate was collected simultaneously from the striatum and the right jugular vein using microdialysis probes. After a single intravenous administration of 10mg/kg mitragynine, mitragynine showed a two-compartmental drug elimination pattern with half-life (T1/2) of approximately 13h. The percent of AUCbrain/AUCplasma of mitragynine was calculated and shown to be 65.8±4.5%. The results indicated that mitragynine could be a suitable molecule to develop into an opioid replacement drug based on its ideal pharmacokinetic properties, namely, small molecular size, lipophilic in nature and with excellent blood-brain barrier (BBB) permeability.
    Matched MeSH terms: Secologanin Tryptamine Alkaloids
  11. Hassan Z, Bosch OG, Singh D, Narayanan S, Kasinather BV, Seifritz E, et al.
    Front Psychiatry, 2017;8:152.
    PMID: 28868040 DOI: 10.3389/fpsyt.2017.00152
    A feature of human culture is that we can learn to consume chemical compounds, derived from natural plants or synthetic fabrication, for their psychoactive effects. These drugs change the mental state and/or the behavioral performance of an individual and can be instrumentalized for various purposes. After the emergence of a novel psychoactive substance (NPS) and a period of experimental consumption, personal and medical benefits and harm potential of the NPS can be estimated on evidence base. This may lead to a legal classification of the NPS, which may range from limited medical use, controlled availability up to a complete ban of the drug form publically accepted use. With these measures, however, a drug does not disappear, but frequently continues to be used, which eventually allows an even better estimate of the drug's properties. Thus, only in rare cases, there is a final verdict that is no more questioned. Instead, the view on a drug can change from tolerable to harmful but may also involve the new establishment of a desired medical application to a previously harmful drug. Here, we provide a summary review on a number of NPS for which the neuropharmacological evaluation has made important progress in recent years. They include mitragynine ("Kratom"), synthetic cannabinoids (e.g., "Spice"), dimethyltryptamine and novel serotonergic hallucinogens, the cathinones mephedrone and methylone, ketamine and novel dissociative drugs, γ-hydroxybutyrate, γ-butyrolactone, and 1,4-butanediol. This review shows not only emerging harm potentials but also some potential medical applications.
    Matched MeSH terms: Secologanin Tryptamine Alkaloids
  12. Al-Khdhairawi AAQ, Krishnan P, Mai CW, Chung FF, Leong CO, Yong KT, et al.
    J Nat Prod, 2017 10 27;80(10):2734-2740.
    PMID: 28926237 DOI: 10.1021/acs.jnatprod.7b00500
    Tengerensine (1), isolated as a racemate and constituted from a pair of bis-benzopyrroloisoquinoline enantiomers, and tengechlorenine (2), purified as a scalemic mixture and constituted from a pair of chlorinated phenanthroindolizidine enantiomers, were isolated from the leaves of Ficus fistulosa var. tengerensis, along with three other known alkaloids. The structures of 1 and 2 were determined by spectroscopic data interpretation and X-ray diffraction analysis. The enantiomers of 1 were separated by chiral-phase HPLC, and the absolute configurations of (+)-1 and (-)-1 were established via experimental and calculated ECD data. Compound 1 is notable in being a rare unsymmetrical cyclobutane adduct and is the first example of a dimeric benzopyrroloisoquinoline alkaloid, while compound 2 represents the first naturally occurring halogenated phenanthroindolizidine alkaloid. Compound (+)-1 displayed a selective in vitro cytotoxic effect against MDA-MB-468 cells (IC50 7.4 μM), while compound 2 showed pronounced in vitro cytotoxic activity against all three breast cancer cell lines tested (MDA-MB-468, MDA-MB-231, and MCF7; IC50 values of 0.038-0.91 μM).
    Matched MeSH terms: Alkaloids/isolation & purification*; Alkaloids/pharmacology*; Alkaloids/chemistry
  13. Singh D, Müller CP, Murugaiyah V, Hamid SBS, Vicknasingam BK, Avery B, et al.
    J Ethnopharmacol, 2018 Mar 25;214:197-206.
    PMID: 29248450 DOI: 10.1016/j.jep.2017.12.017
    ETHNOPHARMACOLOGICAL RELEVANCE: Kratom (Mitragyna speciosa Korth.) from the Rubiaceae family is an indigenous tropical medicinal tree of Southeast Asia. Kratom leaves have been used for decades in Malaysia and Thailand in traditional context for its perceived vast medicinal value, and as a mild stimulant among manual labourers. Kratom consumption has been reported to cause side-effects in kratom users.

    AIM OF THE STUDY: To evaluate kratom's effects towards hematological and clinical-chemistry parameters among regular kratom users in Malaysia.

    METHODS: A total of 77 subjects (n=58 regular kratom users, and n=19 healthy controls) participated in this cross-sectional study. All the surveys were conducted through face-to-face interview to elicit subject's socio-demographic characteristics and kratom use history. A full-blood test was also administered. Laboratory analysis was conducted using GC-MS to determine mitragynine content in the acquired kratom samples in order to relate mitragynine consumption with possible alterations in the blood parameters of kratom users.

    RESULTS: Findings showed that there were no significant differences in the hematological and clinical-chemistry parameters of traditional kratom users and healthy controls, except for HDL and LDL cholesterol values; these were found to be above the normal reference range for the former. Similarly, long-term kratom consumption (>5 years), and quantity of daily kratom use (≥3 ½ glasses; mitragynine content 76.3-114.8mg) did not appear to alter the hematological and biochemical parameters of kratom users.

    CONCLUSION: These data suggest that even long-term and heavy kratom consumption did not significantly alter the hematological and clinical-chemistry parameters of kratom users in a traditional setting.

    Matched MeSH terms: Secologanin Tryptamine Alkaloids/administration & dosage*; Secologanin Tryptamine Alkaloids/adverse effects; Secologanin Tryptamine Alkaloids/isolation & purification
  14. Veeramohan R, Azizan KA, Aizat WM, Goh HH, Mansor SM, Yusof NSM, et al.
    Data Brief, 2018 Jun;18:1212-1216.
    PMID: 29900296 DOI: 10.1016/j.dib.2018.04.001
    Mitragyna speciosa is a psychoactive plant known as "ketum" in Malaysia and "kratom" in Thailand. This plant is distinctly known to produce two important alkaloids, namely mitragynine (MG) and 7-hydroxymitragynine (7-OH-MG) that can bind to opioid receptors [1]. MG was reported to exhibit antidepressant properties in animal studies [2]. These compounds were also proposed to have the potential to replace opioid analgesics with much lower risks of side effects [3]. To date, there are only over 40 metabolites identified in M. speciosa [4,5]. To obtain a more complete profile of secondary metabolites in ketum, we performed metabolomics study using mature leaves of the green M. speciosa variety. The leaf samples were extracted using methanol prior to liquid chromatography-electrospray ionization-time of flight-mass spectrometry (LC-ESI-TOF-MS) analysis. This data can be useful to for the identification of unknown metabolites that are associated with alkaloid biosynthesis pathway in M. speciosa.
    Matched MeSH terms: Secologanin Tryptamine Alkaloids
  15. Abdul Wahab SM, Jantan I, Haque MA, Arshad L
    Front Pharmacol, 2018;9:661.
    PMID: 29973884 DOI: 10.3389/fphar.2018.00661
    The use of anti-inflammatory natural products to treat inflammatory disorders for cancer prevention and therapy is an appealing area of interest in the last decades. Annona muricata L. is one of the many plant extracts that have been explored owing to their anti-inflammatory and anticancer effects. Different parts of A. muricata especially the leaves have been used for various ethnomedicinal purposes by traditional healers to treat several diseases including cancer, inflammation, diabetes, liver diseases, and abscesses. Some of these experience-based claims on the use of the plant have been transformed into evidence-based information by scientific investigations. The leaves of the plant have been extensively investigated for its diverse pharmacological aspects and found eminent for anti-inflammatory and anticancer properties. However, most studies were not on the bioactive isolates which were responsible for the activities but were based on crude extracts of the plant. In this comprehensive review, all significant findings from previous investigations till date on the leaves of A. muricata, specifically on their anti-inflammatory and anticancer activities have been compiled. The toxicology of the plant which has been shown to be due to the presence of neurotoxic annaceous acetogenins and benzyltetrahydro-isoquinoline alkaloids has also been updated to provide recent information on its safety aspects. The present knowledge of the plant has been critically assessed, aimed at providing direction toward improving its prospect as a source of potential anti-inflammatory and anticancer agents. The analysis will provide a new path for ensuring research on this plant to discover new agents to treat inflammatory diseases and cancer. Further in vitro and in vivo studies should be carried out to explore the molecular mechanisms underlying their anti-inflammatory responses in relation to anticancer activity and more detail toxicity study to ensure they are safe for human consumption. Sufficient preclinical data and safety data generated will allow clinical trials to be pursued on this plant and its bioactive compounds.
    Matched MeSH terms: Alkaloids
  16. Babiker, F., Jamal, P., Mirghani, M.E.S., Ansari, A.H.
    MyJurnal
    This study aimed at investigating the presence of alkaloids and other chemical constituents in Datura stramonium (Saikaran, Jimson weed). All parts of the plant were dried, crushed and then underwent extraction by soxhlet and maceration methods. The solvents used in these methods were normal hexane (nonpolar) and ethanol (polar). Thin Layer Chromatography (TLC) and FTIR techniques were used to analyse the chemical components of jimson weed. The results showed the presence of hyoscine in all plant parts while atropine in the seeds only. The best separation was found to be when the solvent system was acetone: water: ammonia (90:07:03). Maceration method is the best and cost effective procedure for extraction.
    Matched MeSH terms: Alkaloids
  17. Malik A, Arooj M, Butt TT, Zahid S, Zahid F, Jafar TH, et al.
    Drug Des Devel Ther, 2018;12:1431-1443.
    PMID: 29872266 DOI: 10.2147/DDDT.S154169
    Background: The present study investigates the hepato- and DNA-protective effects of standardized extracts of Cleome brachycarpa (cabralealactone), Solanum incanum (solasodin), and Salvadora oleioides (salvadorin) in rats.

    Materials and methods: Hepatotoxicity was induced with intraperitoneal injection of carbon tetrachloride (CCl4) (1 mL/kg b.wt.) once a week for 12 weeks. The hepato- and DNA protective effects of the extracts in different combinations were compared with that of a standard drug Clavazin (200 mg/kg b.wt.). Tissue alanine aminotransferase, alpha-fetoprotein, tumor necrosis factor alpha (TNF-α), isoprostanes-2α, malondialdehyde, and 8-hydroxydeoxyguanosine, the significant hallmarks of oxidative stress, were studied.

    Results: Histopathological findings of the liver sections from the rat group which received CCl4+cabralealactone, solasodin, and salvadorin demonstrated improved centrilobular hepatocyte regeneration with moderate areas of congestion and infiltration comparable with Clavazin. For in silico study, the identified compounds were subjected to molecular docking with cyclooxygenase-2 and TNF-α followed by a molecular dynamics study, which indicated their potential as anti-inflammatory agents.

    Conclusion: Cabralealactone, solasodin, and salvadorin confer some hepatoprotective and DNA-damage protective effects against CCl4-induced toxicity. They successfully restored the normal architecture of hepatocytes and have the potential to be used as inhibitor to main culprits, that is, cyclooxygenase-2 and TNF-α. They can combat oxidative stress and liver injuries both as mono and combinational therapies. However, combination therapy has more ameliorating effects.

    Matched MeSH terms: Solanaceous Alkaloids/isolation & purification; Solanaceous Alkaloids/pharmacology*; Solanaceous Alkaloids/chemistry
  18. Krishnan P, Lee FK, Chong KW, Mai CW, Muhamad A, Lim SH, et al.
    Org. Lett., 2018 12 21;20(24):8014-8018.
    PMID: 30543301 DOI: 10.1021/acs.orglett.8b03592
    Two new monoterpenoid indole alkaloids, alstoscholactine (1) and alstolaxepine (2), were isolated from Alstonia scholaris. Compound 1 represents a rearranged stemmadenine alkaloid with an unprecedented C-6-C-19 connectivity, whereas compound 2 represents a 6,7- seco-angustilobine B-type alkaloid incorporating a rare γ-lactone-bridged oxepane ring system. Their structures and absolute configurations were determined by spectroscopic analyses. Compound 1 was successfully semisynthesized from 19 E-vallesamine. Compound 2 induced marked vasorelaxation in rat isolated aortic rings precontracted with phenylephrine.
    Matched MeSH terms: Secologanin Tryptamine Alkaloids/isolation & purification; Secologanin Tryptamine Alkaloids/pharmacology*; Secologanin Tryptamine Alkaloids/chemistry
  19. Heida Nadia Zulkefli, Jamaludin Mohamad, Nurhayati Zainal Abidin
    Sains Malaysiana, 2013;42:697-706.
    Tinospora crispa and Tabernaemontana corymbosa have been used traditionally to treat fever, diabetes, rheumatism and sinusitis. The objective of this study was to evaluate the antioxidant activity of Tinospora crispa and Tabernaemontana corymbosa. The presence of apigenin and magnoflorine was detected using LCMS/MS in Tinospora crispa (Patawali) whereas appararicine, voafinine, conodusarine, conodurine, voacamine and voacangine were detected in Tabernaemontana corymbosa (Susur kelapa) methanol extract. The stem extract of Tinospora crispa showed high antioxidant activity in the following order: DPPH radical scavenging, reducing power and metal chelating assay (98.8%, 0.957, 81.97%) than Tabernaemontana corymbosa of leaves (90.04%, 0.652, 69.64%), stem (82.78%, 0.819, 36.70%) and root extracts (63.25%, 0.469, 51.56%), respectively. The high antioxidant activity in the stem extract of Tinospora crispa is due to the presence of apigenin and magnoflorine. The high antioxidant activity in Tabernaemontana corymbosa extract is due to its high phenol contents. There were significant linear positive correlation (r=0.788, p<0.001, r2=0.621) between the total phenolic content and DPPH free radical scavenging assay in the crude extracts of Tinospora crispa and Tabernaemontana corymbosa. Meanwhile, a significant moderate positive correlation was observed between the total phenolic content and ferric reducing power assay (r= 0.556, p<0.05, r2= 0.309). However, there was no significant difference in the correlation coefficient of total phenolic content and metal chelating assay.
    Matched MeSH terms: Indole Alkaloids
  20. Nguyen DH, Vo TNN, Nguyen NT, Ching YC, Hoang Thi TT
    PLoS One, 2020;15(9):e0239360.
    PMID: 32960911 DOI: 10.1371/journal.pone.0239360
    Exploiting plant extracts to form metallic nanoparticles has been becoming the promising alternative routes of chemical and physical methods owing to environmentally friendly and abundantly renewable resources. In this study, Momordica charantia and Psidium guajava leaf extract (MC.broth and PG.broth) are exploited to fabricate two kinds of biogenic silver nanoparticles (MC.AgNPs and PG.AgNPs). Phytoconstituent screening is performed to identify the categories of natural compounds in MC.broth and PG.broth. Both extracts contain wealthy polyphenols which play a role of reducing agent to turn silver (I) ions into silver nuclei. Trace alkaloids, rich saponins and other oxygen-containing compounds creating the organic corona surrounding nanoparticles act as stabilizing agents. MC.AgNPs and PG.AgNPs are characterized by UV-vis and FTIR spectrophotometry, EDS and TEM techniques. FTIR spectra indicate the presence of O-H, C = O, C-O-C and C = C groups on the surface of silver nanoparticles which is corresponded with three elements of C, O and Ag found in EDS analysis. TEM micrographs show the spherical morphology of MC.AgNPs and PG.AgNPs. MC.AgNPs were 17.0 nm distributed in narrow range of 5-29 nm, while the average size of PG.AgNPs were 25.7 nm in the range of 5-53 nm. Further, MC.AgNPs and PG.AgNPs exhibit their effectively inhibitory ability against A. niger, A. flavus and F. oxysporum as dose-dependence. Altogether, MC.AgNPs and PG.AgNPs will have much potential in scaled up production and become the promising fungicides for agricultural applications.
    Matched MeSH terms: Alkaloids
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