Displaying publications 21 - 40 of 80 in total

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  1. Fulltext (-)-Kunstleramide, a new antioxidant and cytotoxic dienamide from the bark of Beilschmiedia kunstleri gamble
    Mollataghi A, Hadi AH, Cheah SC
    Molecules, 2012 Apr 05;17(4):4197-208.
    PMID: 22481540 DOI: 10.3390/molecules17044197
    A new dienamide, (2E,4E)-7-(3',4'-dimethoxyphenyl)-N-ethyl-6-(R)-hydroxyhepta- 2,4-dienamide, named (-)-kunstleramide (1), were isolated from the bark of Beilschmiedia kunstleri Gamble together with one neolignan: (+)-kunstlerone (2) and seven known alkaloids: (+)-nornuciferine (3), (-)-isocaryachine (4), (+)-cassythicine (5), (+)-laurotetanine (6), (+)-boldine (7), noratherosperminine (8), (+)-N-demethylphyllocaryptine (9). Their structures were established from spectroscopic techniques, most notably 1D- and 2D-NMR, UV, IR, OR, circular dichroism (CD) spectra and LCMS-IT-TOF. (-)-Kunstleramide (1) exhibited very poor dose-dependent inhibition of DPPH activity, with an IC₅₀ value of 179.5 ± 4.4 μg/mL, but showed a moderate cytotoxic effect on MTT assays of A375, A549, HT-29, PC-3 and WRL-68 with EC₅₀ values of 64.65, 44.74, 55.94, 73.87 and 70.95 µg/mL, respectively.
  2. Fulltext Naucline, a new indole alkaloid from the bark of Nauclea officinalis
    Liew SY, Mukhtar MR, Hadi AH, Awang K, Mustafa MR, Zaima K, et al.
    Molecules, 2012 Apr 02;17(4):4028-36.
    PMID: 22469596 DOI: 10.3390/molecules17044028
    A new indole alkaloid, naucline (1) together with four known alkaloids, angustine (2), angustidine (3), nauclefine (4) and naucletine (5), were isolated from the bark of Nauclea officinalis. The structures of all isolated compounds were elucidated with various spectroscopic methods such as 1D- and 2D- NMR, IR, UV and LCMS-IT-TOF. In addition to that of alkaloid 1, the complete 13C-NMR data of naucletine (5) were also reported. Naucline (1) showed a moderate vasorelaxant activity (90% relaxation at 1 × 10(-5) M) whereas, angustine (2), nauclefine (4), and naucletine (5) showed potent vasorelaxant activity (more than 90% relaxation at 1 × 10(-5) M) on an isolated rat aorta.
  3. Zerumbone inhibits interleukin-6 and induces apoptosis and cell cycle arrest in ovarian and cervical cancer cells
    Abdelwahab SI, Abdul AB, Zain ZN, Hadi AH
    Int Immunopharmacol, 2012 Apr;12(4):594-602.
    PMID: 22330084 DOI: 10.1016/j.intimp.2012.01.014
    Interleukin-6 is one of the factors affecting sensitivity to cytotoxic agents. Therefore, the current study was designed to investigate the role of IL-6 and IL6 receptors in the cytotoxic effects of zerumbone in ovarian and cervical cancer cell lines (Caov-3 and HeLa, respectively). Exposure of both cancer cells to zerumbone or cisplatin demonstrated growth inhibition at a dose-dependent manner as determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,Sdiphenyltetrazolium bromide) reduction assay. Both laser scanning confocal microscopy and TUNEL assay showed typical apoptotic features in treated cells. The studies conducted seems to suggest that zerumbone induces cell death by stimulating apoptosis better than cisplatin, based on the significantly higher percentage of apoptotic cells in zerumbone's treated cancer cells as compared to cisplatin. In addition, zerumbone and cisplatin arrest cancer cells at G2/M phase as analyzed by flow cytometry. Our results indicated that zerumbone significantly decreased the levels of IL-6 secreted by both cancer cells. In contrast, HeLa and Caov-3 cells were still sensitive to cisplatin and zerumbone, even in the presence of exogenous IL-6. However, membrane-bound IL-6 receptor is still intact after zerumbone treatment as demonstrated using an immune-fluorescence technique. This study concludes that the compound, zerumbone inhibits both cancer cell growth through the induction of apoptosis, arrests cell cycle at G2/M phase and inhibits the secretion levels of IL-6 in both cancer cells. Therefore, zerumbone is a potential candidate as a useful chemotherapeutic agent in treating both cervical and ovarian cancers in future.
  4. Anti-acetylcholinesterase, anti-α-glucosidase, anti-leishmanial and anti-fungal activities of chemical constituents of Beilschmiedia species
    Mollataghi A, Coudiere E, Hadi AH, Mukhtar MR, Awang K, Litaudon M, et al.
    Fitoterapia, 2012 Mar;83(2):298-302.
    PMID: 22119096 DOI: 10.1016/j.fitote.2011.11.009
    Phytochemical investigation of Beilschmiedia alloiophylla has resulted in the isolation of one new alkaloid, 2-hydroxy-9-methoxyaporphine (1), and ten known natural products, laurotetanine (2), liriodenine (3), boldine (4), secoboldine (5), isoboldine (6), asimilobine (7), oreobeiline (8), 6-epioreobeiline (9), β-amyrone (10), and (S)-3-methoxynordomesticine (11). Chemical studies on the bark of B. kunstleri afforded compounds 2 and 4 along with one bisbenzylisoquinoline alkaloid, N-dimethylphyllocryptine (12). Structures of compounds 1-12 were elucidated on the basis of spectroscopic methods. All of these isolates were evaluated for their anti-acetylcholinesterase (AChE), anti-α-glucosidase, anti-leishmanial and anti-fungal activities. Compounds 1-12 exhibited strong to moderate bioactivities in aforementioned bioassays.
  5. Fulltext Synthesis, characterization, X-ray crystallography, acetyl cholinesterase inhibition and antioxidant activities of some novel ketone derivatives of gallic hydrazide-derived Schiff bases
    Gwaram NS, Ali HM, Abdulla MA, Buckle MJ, Sukumaran SD, Chung LY, et al.
    Molecules, 2012 Feb 28;17(3):2408-27.
    PMID: 22374313 DOI: 10.3390/molecules17032408
    Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.
  6. Fulltext Acute toxicity evaluation, antibacterial, antioxidant and immunomodulatory effects of Melastoma malabathricum
    Alnajar ZA, Abdulla MA, Ali HM, Alshawsh MA, Hadi AH
    Molecules, 2012;17(3):3547-59.
    PMID: 22433579 DOI: 10.3390/molecules17033547
    Melastoma malabathricum (MM) is a well-known plant in Malaysian traditional medicine, locally known as senduduk. Its ethanol and aqueous extracts have been used in the present investigation to study the immunomodulatory role on human peripheral blood mononuclear cell (PBMC), and the DPPH, ABTS and FRAP free radical scavenging activities were also measured. Total flavonoids and total phenolic contents were assayed and the antibacterial effect was tested against four species of bacteria; two Gram-positive (Staphylococcus aureus and Streptococcus agalactiae) and two Gram-negative (Escherichia coli and Klebsilla pneumonia). The tests were carried out using the disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Moreover, the acute toxicity was evaluated in vivo on the ethanol extract of MM to establish its safety when administered orally. In our results, both extracts of MM showed abilities to scavenge DPPH and ABTS free radicals, IC(50) values: (11.599 ± 0.84, 10.573 ± 0.58 µmol/L) and (62.657 ± 0.78, 63.939 ± 0.48 µmol/L) for ethanol and aqueous extracts respectively. Indeed the ethanol extract evidenced high phenolic content (384.33 ± 0.005 mg/g), flavonoids contents (85.8 ± 0.009 mg/g) and ferric reducing antioxidant power (33,590 ± 0.038 mmol/g), with high activity against S. aureus and S. agalactiae (11 ± 0.3 and 12 ± 0.6 mm inhibition zones). Likewise, the percentage of peripheral blood mononuclear cells (PBMC) viability was increased in response to MM, IC(50) values (1.781 ± 1.2 and 6.545 ± 0.93 µg/mL) for ethanol and aqueous extracts, respectively. In addition, our results showed that the MM extract is safe even at a high dose of 5,000 mg/kg and has no oral toxicity. These findings suggest the excellent medicinal bioactivity of MM and explain the popularity of this plant in the folk medicine as a remedy for different illnesses.
  7. Fulltext Ipomoea aquatica extract shows protective action against thioacetamide-induced hepatotoxicity
    Alkiyumi SS, Abdullah MA, Alrashdi AS, Salama SM, Abdelwahab SI, Hadi AH
    Molecules, 2012;17(5):6146-55.
    PMID: 22617138 DOI: 10.3390/molecules17056146
    In the Indian system of traditional medicine (Ayurveda) it is recommended to consume Ipomoea aquatica to mitigate disorders like jaundice. In this study, the protective effects of ethanol extract of I. aquatica against liver damage were evaluated in thioacetamide (TAA)-induced chronic hepatotoxicity in rats. There was no sign of toxicity in the acute toxicity study, in which Sprague-Dawley (SD) rats were orally fed with I. aquatica (250 and 500 mg/kg) for two months along with administration of TAA (i.p injection 200 mg/kg three times a week for two months). The results showed that the treatment of I. aquatica significantly lowered the TAA-induced serum levels of hepatic enzyme markers (ALP, ALT, AST, protein, albumin, bilirubin and prothrombin time). The hepatic content of activities and expressions SOD and CAT that were reduced by TAA were brought back to control levels by the plant extract supplement. Meanwhile, the rise in MDA level in the TAA receiving groups also were significantly reduced by I. aquatica treatment. Histopathology of hepatic tissues by H&E and Masson trichrome stains displayed that I. aquatica has reduced the incidence of liver lesions, including hepatic cells cloudy swelling, infiltration, hepatic necrosis, and fibrous connective tissue proliferation induced by TAA in rats. Therefore, the results of this study show that the protective effect of I. aquatica in TAA-induced liver damage might be contributed to its modulation on detoxification enzymes and its antioxidant and free radical scavenger effects. Moreover, it confirms a scientific basis for the traditional use of I. aquatica for the treatment of liver disorders.
  8. Vasodilator effect of Phlomis bracteosa constituents is mediated through dual endothelium-dependent and endothelium-independent pathways
    Khan AU, Ullah R, Khan A, Mustafa MR, Hussain J, Murugan DD, et al.
    Clin Exp Hypertens, 2012;34(2):132-9.
    PMID: 21967029 DOI: 10.3109/10641963.2011.601383
    This study describes the vasorelaxant potential of some pure compounds isolated from Phlomis bracteosa L. marrubiin, phlomeoic acid, and two new constituents labeled as RA and RB. In rat thoracic aortic rings denuded of endothelium, marrubiin, phlomeoic acid, RA, and RB caused relaxation of high K(+) (80 mM) and phenylephrine (1 μM)-induced contractions at the concentration range of 1.0-1000 μg/mL. Marrubiin, phlomeoic acid, RA, and RB concentration dependently (3.0-10 μg/mL) shifted the Ca(++) curves to the right obtained in Ca(++)-free medium. The vasodilator effect of marrubiin, phlomeoic acid, RA, and RB was partially blocked by N(ω)-nitro-L-arginine methyl ester in endothelium-intact aorta preparations. These results reveal that P. bracteosa constituents: marrubiin, phlomeoic acid, RA, and RB exhibit vasodilator action occurred via a combination of endothelium-independent Ca(++) antagonism and endothelium-dependent N(ω)-nitro-L-arginine methyl ester-sensitive nitric oxide-modulating mechanism.
  9. Fulltext Acute toxicity and gastroprotection studies of a new schiff base derived copper (II) complex against ethanol-induced acute gastric lesions in rats
    Hajrezaie M, Golbabapour S, Hassandarvish P, Gwaram NS, A Hadi AH, Mohd Ali H, et al.
    PLoS One, 2012;7(12):e51537.
    PMID: 23251568 DOI: 10.1371/journal.pone.0051537
    BACKGROUND: Copper is an essential element in various metabolisms. The investigation was carried out to evaluate acute gastroprotective effects of the Copper (II) complex against ethanol-induced superficial hemorrhagic mucosal lesions in rats.

    METHODOLOGY/PRINCIPAL FINDINGS: Rats were divided into 7 groups. Groups 1 and 2 were orally administered with Tween 20 (10% v/v). Group 3 was orally administered with 20 mg/kg omeprazole (10% Tween 20). Groups 4-7 received 10, 20, 40, and 80 mg/kg of the complex (10% Tween 20), respectively. Tween 20 (10% v/v) was given orally to group 1 and absolute ethanol was given orally to groups 2-7, respectively. Rats were sacrificed after 1 h. Group 2 exhibited severe superficial hemorrhagic mucosal lesions. Gastric wall mucus was significantly preserved by the pre-treatment complex. The results showed a significant increase in glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO), and Prostaglandin E2 (PGE(2)) activities and a decrease in malondialdehyde (MDA) level. Histology showed marked reduction of hemorrhagic mucosal lesions in groups 4-7. Immunohistochemical staining showed up-regulation of Hsp70 and down-regulation of Bax proteins. PAS staining of groups 4-7 showed intense stain uptake of gastric mucosa. The acute toxicity revealed the non-toxic nature of the compound.

    CONCLUSIONS/SIGNIFICANCE: The gastroprotective effect of the Copper (II) complex may possibly be due to preservation of gastric wall mucus; increase in PGE(2) synthesis; GSH, SOD, and NO up-regulation of Hsp70 protein; decrease in MDA level; and down-regulation of Bax protein.

  10. Fulltext Cardiovascular activity of labdane diterpenes from Andrographis paniculata in isolated rat hearts
    Awang K, Abdullah NH, Hadi AH, Fong YS
    J Biomed Biotechnol, 2012;2012:876458.
    PMID: 22536026 DOI: 10.1155/2012/876458
    The dichloromethane (DCM) extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5 ± 3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5 ± 11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1), 14-deoxy-11,12-didehydroandrographolide (2), 14-deoxyandrographolide (3), andrographolide (4), and neoandrographolide (5), were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2) and (3) were responsible for the coronary vasodilatation. This study also showed that andrographolide (4), the major labdane diterpene in this plant, has minimal effects on the heart.
  11. Fulltext Mechanisms of Gastroprotective Effects of Ethanolic Leaf Extract of Jasminum sambac against HCl/Ethanol-Induced Gastric Mucosal Injury in Rats
    Alrashdi AS, Salama SM, Alkiyumi SS, Abdulla MA, Hadi AH, Abdelwahab SI, et al.
    Evid Based Complement Alternat Med, 2012;2012:786426.
    PMID: 22550543 DOI: 10.1155/2012/786426
    Jasminum sambac is used in folk medicine as the treatment of many diseases. The aim of the present investigation is to evaluate the gastroprotective effects of ethanolic extracts of J. sambac leaves against acidified ethanol-induced gastric ulcers in rats. Seven groups of rats were orally pre-treated with carboxymethylcellulose (CMC) as normal group, CMC as ulcer group, 20 mg/kg of omeprazole as positive group, 62.5, 125, 250, and 500 mg/kg of extract as the experimental groups, respectively. An hour later, CMC was given orally to normal group and acidified ethanol solution was given orally to the ulcer control, positive control, and the experimental groups. The rats were sacrificed after an hour later. Acidity of gastric content, the gastric wall mucus, ulcer areas, and histology and immunohistochemistry of the gastric wall were assessed. Gastric homogenates were determined for prostaglandin E(2) (PGE(2)), superoxide dismutase (SOD), andmalondialdehyde (MDA) content. Ulcer group exhibited significantly severe mucosal injury as compared with omeprazole or extract which shows significant protection towards gastric mucosal injury the plant promotes ulcer protection as it shows significant reduction of ulcer area grossly, and histology showed marked reduction of edema and leucocytes infiltration of submucosal layer compared with ulcer group. Immunohistochemistry showed overexpression of Hsp70 protein and downexpression of Bax protein in rats pretreated with extract. Significant increased in the pH, mucus of gastric content and high levels of PGE(2), SOD and reduced amount of MDA was observed.
  12. Fulltext Cucurbitacin L 2-O-β-Glucoside Demonstrates Apoptogenesis in Colon Adenocarcinoma Cells (HT-29): Involvement of Reactive Oxygen and Nitrogen Species Regulation
    Abdelwahab SI, Hassan LE, Abdul Majid AM, Yagi SM, Mohan S, Elhassan Taha MM, et al.
    Evid Based Complement Alternat Med, 2012;2012:490136.
    PMID: 22685485 DOI: 10.1155/2012/490136
    Emerging evidence suggests that reactive oxygen (ROS) and nitrogen (RNS) species can contribute to diverse signalling pathways of inflammatory and tumour cells. Cucurbitacins are a group of highly oxygenated triterpenes. Many plants used in folk medicine to treat cancer have been found to contain cucurbitacins displaying potentially important anti-inflammatory actions. The current study was designed to investigate the anti-ROS and -RNS effects of cucurbitacin L 2-O-β-glucoside (CLG) and the role of these signaling factors in the apoptogenic effects of CLG on human colon cancer cells (HT-29). This natural cucurbitacin was isolated purely from Citrullus lanatus var. citroides (Cucurbitaceae). The results revealed that CLG was cytotoxic to HT-29. CLG increased significantly (P < 0.05) RNA and protein levels of caspase-3 in HT-29 cells when verified using a colorimetric assay and realtime qPCR, respectively. The results showed that lipopolysaccharide/interferon-gamma (LPS/INF-γ) increased nitrous oxide (NO) production inR AW264.7macrophages, whereas N(G)-nitro-L-argininemethyl ester (L-NAME) and CLG curtailed it. This compound did not reveal any cytotoxicity on RAW264.7 macrophages and human normal liver cells (WRL-68) when tested using the MTT assay. Findings of ferric reducing antioxidant power (FRAP) and oxygen radical absorption capacity (ORAC) assays demonstrate the antioxidant properties of CLG. The apoptogenic property of CLG on HT-29 cells is thus related to inhibition of reactive nitrogen and oxygen reactive species and the triggering of caspase-3-regulated apoptosis.
  13. Fulltext Protective Role of Phyllanthus niruri Extract against Thioacetamide-Induced Liver Cirrhosis in Rat Model
    Amin ZA, Bilgen M, Alshawsh MA, Ali HM, Hadi AH, Abdulla MA
    Evid Based Complement Alternat Med, 2012;2012:241583.
    PMID: 22649471 DOI: 10.1155/2012/241583
    A preclinical study was performed to determine if the extract from Phyllanthus niruri (PN) plays a protective role against liver cirrhosis induced by thioacetamide (TAA) in rats. Initially, acute toxicity was tested and the results showed that the extract was benign when applied to healthy rats. Next, the therapeutic effect of the extract was investigated using five groups of rats: control, TAA, silymarin, and PN high dose and low dose groups. Significant differences were observed between the TAA group and the other groups regarding body and liver weights, liver biochemical parameters, total antioxidant capacity, lipid peroxidation, and oxidative stress enzyme levels. Gross visualization indicated coarse granules on the surface of the hepatotoxic rats' livers, in contrast to the smoother surface in the livers of the silymarin and PN-treated rats. Histopathological analysis revealed necrosis, lymphocytes infiltration in the centrilobular region, and fibrous connective tissue proliferation in the livers of the hepatotoxic rats. But, the livers of the treated rats had comparatively minimal inflammation and normal lobular architecture. Silymarin and PN treatments effectively restored these measurements closer to their normal levels. Progression of liver cirrhosis induced by TAA in rats can be intervened using the PN extract and these effects are comparable to those of silymarin.
  14. Fulltext Neonaucline, a new indole alkaloid from the leaves of Ochreinauclea maingayii (Hook. f.) Ridsd. (Rubiaceae)
    Muktar MR, Osman N, Awang K, Hazni H, Qureshi AK, Hadi AH, et al.
    Molecules, 2011 Dec 28;17(1):267-74.
    PMID: 22205092 DOI: 10.3390/molecules17010267
    A new indole alkaloid; neonaucline (1), along with six known compounds-Cadamine (2), naucledine (3), harmane, benzamide, cinnamide and blumenol A-were isolated from the leaves of Ochreinauclea maingayii (Rubiaceae). In addition to that of compound 1, (13)C-NMR data of cadamine (2) and naucledine (3) were also reported. Structural elucidations of these alkaloids were performed using spectroscopic methods especially 1D- and 2D-NMR, IR, UV and LCMS-IT-TOF. The excellent vasorelaxant activity on isolated rat aorta was observed for the alkaloids 1-3 after injection of each sample at 1 × 10(-5) M.
  15. Anti-inflammatory activities of cucurbitacin E isolated from Citrullus lanatus var. citroides: role of reactive nitrogen species and cyclooxygenase enzyme inhibition
    Abdelwahab SI, Hassan LE, Sirat HM, Yagi SM, Koko WS, Mohan S, et al.
    Fitoterapia, 2011 Dec;82(8):1190-7.
    PMID: 21871542 DOI: 10.1016/j.fitote.2011.08.002
    The in vivo and in vitro mechanistic anti-inflammatory actions of cucurbitacin E (CE) (Citrullus lanatus var. citroides) were examined. The results showed that LPS/INF-γ increased NO production in RAW264.7 macrophages, whereas L-NAME and CE curtailed it. CE did not reveal any cytotoxicity on RAW264.7 and WRL-68 cells. CE inhibited both COX enzymes with more selectivity toward COX-2. Intraperitoneal injection of CE significantly suppressed carrageenan-induced rat's paw edema. ORAC and FRAP assays showed that CE is not a potent ROS scavenger. It could be concluded that CE is potentially useful in treating inflammation through the inhibition of COX and RNS but not ROS.
  16. Fulltext Synthesis, characterization, acetylcholinesterase inhibition, molecular modeling and antioxidant activities of some novel Schiff bases derived from 1-(2-ketoiminoethyl)piperazines
    Salga SM, Ali HM, Abdullah MA, Abdelwahab SI, Wai LK, Buckle MJ, et al.
    Molecules, 2011 Nov 07;16(11):9316-30.
    PMID: 22064271 DOI: 10.3390/molecules16119316
    Some novel Schiff bases derived from 1-(2-ketoiminoethyl)piperazines were synthesized and characterized by mass spectroscopy, FTIR, UV-Visible, 1H and 13C-NMR. The compounds were tested for inhibitory activities on human acetylcholinesterase (hAChE), antioxidant activities, acute oral toxicity and further studied by molecular modeling techniques. The study identified the compound (DHP) to have the highest activity among the series in hAChE inhibition and DPPH assay while the compound LP revealed the highest activity in the FRAP assay. The hAChE inhibitory activity of DHP is comparable with that of propidium, a known AChE inhibitor. This high activity of DHP was checked by molecular modeling which showed that DHP could not be considered as a bivalent ligand due to its incapability to occupy the esteratic site (ES) region of the 3D crystal structure of hAChE. The antioxidant study unveiled varying results in 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. This indicates mechanistic variations of the compounds in the two assays. The potential therapeutic applications and safety of these compounds were suggested for use as human acetylcholinesterase inhibitors and antioxidants.
  17. Malabaricone C from Myristica cinnamomea exhibits anti-quorum sensing activity
    Chong YM, Yin WF, Ho CY, Mustafa MR, Hadi AH, Awang K, et al.
    J Nat Prod, 2011 Oct 28;74(10):2261-4.
    PMID: 21910441 DOI: 10.1021/np100872k
    A methanol-soluble extract of the bark of Myristica cinnamomea was found to exhibit anti-quorum sensing activity, and subsequent bioassay-guided isolation led to the identification of the active compound malabaricone C (1). Compound 1 inhibited violacein production by Chromobacterium violaceum CV026 when grown in the presence of a cognate signaling molecule, N-3-oxohexanoyl-homoserine lactone. Furthermore, 1 inhibited the quorum sensing-regulated pyocyanin production and biofilm formation in Pseudomonas aeruginosa PAO1. These results suggest that the anti-quorum sensing activity of 1 and related molecules should be investigated further.
  18. Fulltext (+)-Kunstlerone, a new antioxidant neolignan from the Leaves of Beilschmiedia kunstleri gamble
    Mollataghi A, Hadi AH, Awang K, Mohamad J, Litaudon M, Mukhtar MR
    Molecules, 2011 Aug 04;16(8):6582-90.
    PMID: 21818061 DOI: 10.3390/molecules16086582
    A new neolignan, 3,4-dimethoxy-3',4'-methylenedioxy-2,9-epoxy-6,7-cyclo-1,8-neolign-11-en-5(5H)-one, which has been named (+)-kunstlerone (1), together with six known alkaloids: (+)-norboldine (2), (+)-N-methylisococlaurine (3), (+)-cassythicine (4), (+)-laurotetanine (5), (+)-boldine (6) and (-)-pallidine (7), were isolated from the leaves of Beilschmiedia kunstleri. The structures were established through various spectroscopic methods notably 1D- and 2D-NMR, UV, IR and LCMS-IT-TOF. (+)- Kunstlerone (1) showed a strong antioxidant activity, with an SC(50) of 20.0 µg/mL.
  19. Chisomicines A-C, limonoids from Chisocheton ceramicus
    Najmuldeen IA, Hadi AH, Awang K, Mohamad K, Ketuly KA, Mukhtar MR, et al.
    J Nat Prod, 2011 May 27;74(5):1313-7.
    PMID: 21428417 DOI: 10.1021/np200013g
    Three new limonoids, chisomicines A-C (1-3), have been isolated from the bark of Chisocheton ceramicus. Their structures were determined by 2D NMR, CD spectroscopic methods, and X-ray analysis. Chisomicine A (1) exhibited NO production inhibitory activity in J774.1 cells stimulated by LPS dose-dependently at high cell viability.
  20. Fulltext 17-Deoxoestrone [estra-1,3,5(10)-trien-3-ol]-methanol (3/1)
    Ketuly KA, Hadi AH, Ng SW, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2011 May 1;67(Pt 5):o1160-1.
    PMID: 21754468 DOI: 10.1107/S1600536811013651
    Three independent mol-ecules of the title estrone derivative and a mol-ecule of methanol comprise the asymmetric unit of the title compound [systematic name: 13-methyl-6,7,8,9,11,12,13,14,15,16-deca-hydro-cyclo-penta-[a]phenanthren-3-ol-meth-an-ol (3/1)], 3C(18)H(24)O·CH(3)OH. Two of the estrone mol-ecules exhibit 50:50 disorder (one displays whole-mol-ecule disorder and the other partial disorder in the fused five- and six-membered rings) so that five (partial) mol-ecular conformations are discernable. The conformation of the six-membered ring abutting the aromatic ring is close to a half-chair in all five components. The conformation of the six-membered ring fused to the five-membered ring is based on a chair with varying degrees of distortion ranging from minor to significant. Two distinct conformations are found for the five-membered ring: in four mol-ecules, the five-membered ring is twisted about the bond linking it to the six-membered ring, and in the other, the five-membered ring is an envelope with the quaternary C atom being the flap atom. The crystal packing features O-H⋯O hydrogen bonding whereby the four mol-ecules comprising the asymmetric unit are linked into a supra-molecular chain along the b axis.
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