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Fulltext 17-(5-Ethyl-6-methyl-heptan-2-yl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetra-deca-hydro-1H-cyclo-penta[a]phenanthrene-3,7-diol from Chisocheton tomentosus (Meliaceae)

Najmuldeen IA, Hadi AH, Awang K, Mohamad K, Ng SW

Acta Crystallogr Sect E Struct Rep Online, 2008;64(Pt 11):o2163.
PMID: 21581023 DOI: 10.1107/S1600536808033163

The asymmetric unit of the title compound, C(29)H(50)O(2), contains two mol-ecules; one mol-ecule is linked to the other by two O-H⋯O hydrogen bonds, whereas only one of the hydr-oxy groups of the second mol-ecule is involved in hydrogen bonding. This gives rise to a chain that runs along the a axis of the monoclinic unit cell.
Fulltext 3-Oxoolean-1-en-28-oic acid-n-hexa-ne-water (4/1/1) from the bark of Walsura pinnata Hassk

Awang K, Yusoff M, Mohamad K, Chong SL, Ng SW

Acta Crystallogr Sect E Struct Rep Online, 2009;65(Pt 5):o1166.
PMID: 21583968 DOI: 10.1107/S1600536809015086

3-Oxoolean-1-en-28-oic acid, isolated from the bark of Walsura pinnata Hassk, crystallized from n-hexane as an n-hexane 0.25-solvent 0.25-hydrate, C(30)H(46)O(3)·0.25C(6)H(14)·0.25H(2)O. There are two independent mol-ecules in the asymmetric unit of the title compound. The three six-membered cyclo-hexane rings in each mol-ecule adopt chair conformations and the carboxyl substituent occupies an axial/equatorial position. The two independent mol-ecules are linked by a pair of O-H(carbox-yl)⋯O hydrogen bonds into a dimer. The n-hexane mol-ecule is disordered about a twofold rotation axis and the water mol-ecule lies on a twofold rotation axis. In addition, the cyclo-hexone carbonyl group of one of the independent mol-ecules is disordered over two sites with occupancies of 0.75 and 0.25.
7α-Hydroxy-β-Sitosterol from Chisocheton tomentosus Induces Apoptosis via Dysregulation of Cellular Bax/Bcl-2 Ratio and Cell Cycle Arrest by Downregulating ERK1/2 Activation

Tasyriq M, Najmuldeen IA, In LL, Mohamad K, Awang K, Hasima N

Evid Based Complement Alternat Med, 2012;2012:765316.
PMID: 22997533

In continuation of our interest towards the elucidation of apoptotic pathways of cytotoxic phytocompounds, we have embarked upon a study on the anticancer effects of 7α-hydroxy-β-sitosterol (CT1), a rare natural phytosterol oxide isolated from Chisocheton tomentosus. CT1 was found to be cytotoxic on three different human tumor cell lines with minimal effects on normal cell controls, where cell viability levels were maintained ≥80% upon treatment. Our results showed that cell death in MCF-7 breast tumor cells was achieved through the induction of apoptosis via downregulation of the ERK1/2 signaling pathway. CT1 was also found to increase proapoptotic Bax protein levels, while decreasing anti-apoptotic Bcl-2 protein levels, suggesting the involvement of the intrinsic pathway. Reduced levels of initiator procaspase-9 and executioner procaspase-3 were also observed following CT1 exposure, confirming the involvement of cytochrome c-mediated apoptosis via the mitochondrial pathway. These results demonstrated the cytotoxic and apoptotic ability of 7α-hydroxy-β-sitosterol and suggest its potential anti-cancer use particularly on breast adenocarcinoma cells.
An ethnobotanical study of medicinal plants used by tribal and native people of Madhupur forest area, Bangladesh

Islam MK, Saha S, Mahmud I, Mohamad K, Awang K, Jamal Uddin S, et al.

J Ethnopharmacol, 2014 Feb 3;151(2):921-30.
PMID: 24342778 DOI: 10.1016/j.jep.2013.11.056

Madhupur forest area, Tangail is one of early human settlements in Bangladesh. Having abode in the vicinity of the forest, a strong ethnobotanical practice has prevailed in this area since ancient time. Due to the rapid deforestation during the last few decades, many plants have already disappeared or are facing extinction. Thus we attempted to document the medicinal plant use of Madhupur forest area with a view to preserve the ethnobotanical knowledge and in order to protect the biodiversity of this area.
Fulltext Apolipoprotein Eε4: A Biomarker for Executive Dysfunction among Parkinson's Disease Patients with Mild Cognitive Impairment

Samat NA, Abdul Murad NA, Mohamad K, Abdul Razak MR, Mohamed Ibrahim N

Front Neurosci, 2017;11:712.
PMID: 29326545 DOI: 10.3389/fnins.2017.00712

Background: Cognitive impairment is prevalent in Parkinson's disease (PD), affecting 15-20% of patients at diagnosis. α-synuclein expression and genetic polymorphisms of Apolipoprotein E (ApoE) have been associated with the presence of cognitive impairment in PD although data have been inconsistent. Objectives: To determine the prevalence of cognitive impairment in patients with PD using Montreal Cognitive Assessment (MoCA), Comprehensive Trail Making Test (CTMT) and Parkinson's disease-cognitive rating scale (PDCRS), and its association with plasma α-synuclein and ApoE genetic polymorphisms. Methods: This was across-sectional study involving 46 PD patients. Patients were evaluated using Montreal cognitive assessment test (MoCA), and detailed neuropsychological tests. The Parkinson's disease cognitive rating scale (PDCRS) was used for cognitive function and comprehensive trail making test (CTMT) for executive function. Blood was drawn for plasma α-synuclein measurements and ApoE genetic analysis. ApoE polymorphism was detected using MutaGELAPoE from ImmunDiagnostik. Plasma α-synuclein was detected using the ELISA Technique (USCN Life Science Inc.) according to the standard protocol. Results: Based on MoCA, 26 (56.5%) patients had mild cognitive impairment (PD-MCI) and 20 (43.5%) had normal cognition (PD-NC). Based on the PDCRS, 18 (39.1%) had normal cognition (PDCRS-NC), 17 (37%) had mild cognitive impairment (PDCRS-MCI), and 11 (23.9%) had dementia (PDCRS-PDD). In the PDCRS-MCI group, 5 (25%) patients were from PD-NC group and all PDCRS-PDD patients were from PD-MCI group. CTMT scores were significantly different between patients with MCI and normal cognition on MoCA (p = 0.003). Twenty one patients (72.4%) with executive dysfunction were from the PD-MCI group; 17 (77.3%) with severe executive dysfunction and 4 (57.1%) had mild to moderate executive dysfunction. There were no differences in the plasma α-synuclein concentration between the presence or types of cognitive impairment based on MoCA, PDCRS, and CTMT. TheApoEe4 allele carrier frequency was significantly higher in patients with executive dysfunction (p = 0.014). Conclusion: MCI was prevalent in our PD population. PDCRS appeared to be more discriminatory in detecting MCI and PDD than MoCA. Plasma α-synuclein level was not associated with presence nor type of cognitive impairment, but the ApoEe4 allele carrier status was significantly associated with executive dysfunction in PD.
Bioactivity-guided fractionation of the lipoxygenase and cyclooxygenase inhibiting constituents from Chisocheton polyandrus Merr

Chan KY, Mohamad K, Ooi AJ, Imiyabir Z, Chung LY

Fitoterapia, 2012 Jul;83(5):961-7.
PMID: 22565147 DOI: 10.1016/j.fitote.2012.04.018

Lipoxygenase (LOX)-inhibiting compounds from the leaves of Chisocheton polyandrus Merr. were isolated in this study using a bioactivity-guided fractionation technique. Two dammarane triterpenoids, dammara-20,24-dien-3-one (1) (IC(50)=0.69±0.07 μM) and 24-hydroxydammara-20,25-dien-3-one (2) (IC(50)=1.11±0.38 μM), were isolated and identified based on the soybean LOX assay. Dammara-20,24-dien-3-one (1) exhibited dual inhibition of both human 5-LOX (IC(50)=24.27±2.92 μM) and cyclooxygenase-2 (COX-2) (IC(50)=3.17±0.90 μM), whereas 24-hydroxydammara-20,25-dien-3-one (2) did not exhibit any significant inhibitory effects. This report is the first to detail the inhibition of LOX and COX by both C. polyandrus and its isolated compounds.
Characterization of a multiwavelength Brillouin-erbium fiber laser based on a linear cavity configuration

Al-Mansoori MH, Saharudin S, Abdul-Rashid H, Mahdi MA, Abdullah MK

Appl Opt, 2005 May 10;44(14):2827-31.
PMID: 15943335

We experimentally demonstrate a simple method for generating a multiwavelength Brillouin comb by utilizing a linear cavity of hybrid Brillouin-erbium fiber lasers (BEFLs). The optimization of Brillouin pump wavelength, power, and erbium gain played a significant role in determining the maximum number of Brillouin Stokes signals generated. Simultaneous and stable multiple-wavelength laser output of 22 lines with 10.88-GHz channel spacing has been obtained with good flatness. Various parameters such as 980-nm pump power, Brillouin pump wavelength, and Brillouin pump power that affect the performance of a multiwavelength BEFL system have been investigated. An analysis of the tuning range of the system is presented.
Fulltext Chemical constituents of aglaia lanuginose

Kamarulzaman, F. A., Mohamad, K., Awang, K., Lee, H. B.

Pertanika Journal of Science & Technology, 2014;22(1):163-174.
MyJurnal

Our continuing research on the Aglaia genus (family Meliaceace) has led us to this first study on the chemical constituents of Aglaia lanuginose (bark). The dichloromethane extract from the bark of Aglaia lanuginose showed cytotoxicity against HL-60 leukaemia cell line (45% inhibition) at 20 µg/ml and was prioritised for further investigation. Repeated chromatography of the dichloromethane extract yielded the known dammarane triterpenes which were identified as cabralealactone (1), methyl eichlerianate (2), cabraleone (3), ocotillone (4), eichleriatone (5), eichlerianic acid (6) and shoreic acid (7) together with the known sterols, sitosterol (9) and stigmasterol (10). Another isolated compound was the aromatic 4-hydroxycinnamyl-acetate (8), which has not been reported to be present in a plant from the Meliaceae family. The structures of all the compounds were elucidated on the basis of spectroscopic methods (IR, MS and NMR). Cytotoxicity testing of 1-10 showed activity only for mixtures of (3, 4), and (5, 6).
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.
Fulltext Cognitive impairment and memory dysfunction after a stroke diagnosis: a post-stroke memory assessment

Al-Qazzaz NK, Ali SH, Ahmad SA, Islam S, Mohamad K

Neuropsychiatr Dis Treat, 2014;10:1677-91.
PMID: 25228808 DOI: 10.2147/NDT.S67184

Cognitive impairment and memory dysfunction following stroke diagnosis are common symptoms that significantly affect the survivors' quality of life. Stroke patients have a high potential to develop dementia within the first year of stroke onset. Currently, efforts are being exerted to assess stroke effects on the brain, particularly in the early stages. Numerous neuropsychological assessments are being used to evaluate and differentiate cognitive impairment and dementia following stroke. This article focuses on the role of available neuropsychological assessments in detection of dementia and memory loss after stroke. This review starts with stroke types and risk factors associated with dementia development, followed by a brief description of stroke diagnosis criteria and the effects of stroke on the brain that lead to cognitive impairment and end with memory loss. This review aims to combine available neuropsychological assessments to develop a post-stroke memory assessment (PSMA) scheme based on the most recognized and available studies. The proposed PSMA is expected to assess different types of memory functionalities that are related to different parts of the brain according to stroke location. An optimal therapeutic program that would help stroke patients enjoy additional years with higher quality of life is presented.
Cytotoxic 3,4-secoapotirucallanes from Aaglaia argentea bark

Mohamad K, Martin MT, Najdar H, Gaspard C, Sévenet T, Awang K, et al.

J Nat Prod, 1999 Jun;62(6):868-72.
PMID: 10395505

Nine 3,4-secoapotirucallanes, argentinic acids A-I, were isolated from the bark of Aglaia argentea and transformed to their methyl esters 1-9. The structures were determined by spectral and chemical means. Compounds 1-8 showed moderate cytotoxic activity against KB cells (IC50 1.0-3.5 microg/mL).
Fulltext Cytotoxic and antioxidant compounds from the stem bark of Goniothalamus tapisoides Mat Salleh

Kim RP, Bihud V, Bin Mohamad K, Leong KH, Bin Mohamad J, Bin Ahmad F, et al.

Molecules, 2012 Dec 21;18(1):128-39.
PMID: 23344192 DOI: 10.3390/molecules18010128

Eleven compounds:goniomicin A (1), goniomicin B (2), goniomicin C (3), goniomicin D (4), tapisoidin (5), goniothalamin (6), 9-deoxygoniopypyrone (7), pterodondiol (8), liriodenine (9), benzamide (10) and cinnamic acid (11), were isolated from the stem bark of Goniothalamus tapisoides. All compounds were identified by spectroscopic analysis and, for known compounds, by comparison with published data. Goniothalamin (6) exhibited mild cytotoxic activity towards a colon cancer cell line (HT-29), with an IC(50)value of 64.17 ± 5.60 µM. Goniomicin B (2) give the highest antioxidant activity in the DPPH assay among all compounds tested, with an IC(50) of 0.207 µM.
Depression and Severity of Glaucoma Among Older Adults in Urban and Suburban Areas

Tharmathurai S, Muhammad-Ikmal MK, Razak AA, Che-Hamzah J, Azhany Y, Fazilawati Q, et al.

J Glaucoma, 2021 May 01;30(5):e205-e212.
PMID: 33710066 DOI: 10.1097/IJG.0000000000001830

PRCIS: Depression increases with severity of visual field defect in older adults with primary open-angle glaucoma (POAG).
PURPOSE: This study aimed to determine the prevalence of depression among patients with POAG and examine the relationship between depression and the severity of POAG in older adults.
MATERIALS AND METHODS: Three hundred and sixty patients with POAG aged 60 years or above were recruited from 2 tertiary centers located in an urban and suburban area. The participants were stratified according to the severity of their glaucoma based on the scores from the modified Advanced Glaucoma Intervention Study (AGIS) to mild, moderate, severe, and end stage. Face-to-face interviews were performed using the Malay Version Geriatric Depression Scale 14 (mGDS-14) questionnaire. Depression is diagnosed when the score is ≥8. One-way analysis of variance was used to compare the subscores between the groups. Multifactorial analysis of variance was also applied with relevant confounding factors.
RESULTS: Depression was detected in 16% of older adults with POAG; a higher percentage of depression was seen in those with end stage disease. There was a significant increase in the mean score of mGDS-14 according to the severity of POAG. There was evidence of an association between depression and severity of visual field defect (P<0.001). There was a significant difference in mGDS-14 score between the pairing of severity of POAG [mild-severe (P=0.003), mild-end stage (P<0.001), moderate-severe (P<0.001), and moderate-end stage (P<0.001)] after adjustment to living conditions, systemic disease, and visual acuity.
CONCLUSION: Ophthalmologists should be aware that older adults with advanced visual field defects in POAG may have depression. The detection of depression is important to ensure adherence and persistence to the treatment of glaucoma.
Fulltext Design, synthesis and cytotoxic evaluation of o-carboxamido stilbene analogues

Azmi MN, Din MF, Kee CH, Suhaimi M, Ping AK, Ahmad K, et al.

Int J Mol Sci, 2013;14(12):23369-89.
PMID: 24287912 DOI: 10.3390/ijms141223369

Resveratrol, a natural stilbene found in grapes and wines exhibits a wide range of pharmacological properties. Resveratrol is also known as a good chemopreventive agent for inhibiting carcinogenesis processes that target kinases, cyclooxygenases, ribonucleotide reductase and DNA polymerases. A total of 19 analogues with an amide moiety were synthesized and the cytotoxic effects of the analogues on a series of human cancer cell lines are reported. Three compounds 6d, 6i and 6n showed potent cytotoxicity against prostate cancer DU-145 (IC50=16.68 µM), colon cancer HT-29 (IC50=7.51 µM) and breast cancer MCF-7 (IC50=21.24 µM), respectively, which are comparable with vinblastine. The resveratrol analogues were synthesized using the Heck method.
Fulltext Effects of moringa leaves (Moringa oleifera) extraction on quality changes and melanosis of giant freshwater prawn (Macrobrachium rosenbergii) during chilled storage

Karim NU, Siddiq USAA, Razak MRM, Zainol MKM, Abdullah MI

Ital J Food Saf, 2018 Sep 26;7(3):6846.
PMID: 30538958 DOI: 10.4081/ijfs.2018.6846

An aqueous extraction of moringa (Moringa oleifera) leaves were prepared as the edible coats for keeping the quality of the giant freshwater prawn (Macrobrachium rosenbergii). In addition, the antioxidant properties and activity; total phenolic content (TPC), total flavonoid contents (TFC), free radical scavenging activity (DPPH), and ferric reducing antioxidant power (FRAP) of moringa leaves were also determined. The phenolic compounds and antioxidant properties in the moringa leaves are low; 16.14 mgGAEg-1 for TPC; 5.57 mgQEg-1 for TFC; 1.36 mgTEg-1 for DPPH; and 3.05 mgTEg-1 for FRAP. The experiment was further conducted by coating the M. rosenbergii with moringa leaves extraction before chilled storage at 4°C for 15 days. Moringa leaves extraction were effectively reduced the microflora count in M. rosenbergii (P<0.05). Total volatile basis nitrogen (TVB-N) value showed a significant (P<0.05) lower amount in treated samples compared to the controls. Melanosis were obvious in controls compared to the treated samples. After 15 days of chilled storage, the sensory properties; taste, texture and odour of treated samples were acceptable by the panelists. Biopreservation of moringa leaves extraction significantly benefits in keeping the quality of M. rosenbergii.
Emotion classification in Parkinson's disease by higher-order spectra and power spectrum features using EEG signals: a comparative study

Yuvaraj R, Murugappan M, Ibrahim NM, Omar MI, Sundaraj K, Mohamad K, et al.

J Integr Neurosci, 2014 Mar;13(1):89-120.
PMID: 24738541 DOI: 10.1142/S021963521450006X

Deficits in the ability to process emotions characterize several neuropsychiatric disorders and are traits of Parkinson's disease (PD), and there is need for a method of quantifying emotion, which is currently performed by clinical diagnosis. Electroencephalogram (EEG) signals, being an activity of central nervous system (CNS), can reflect the underlying true emotional state of a person. This study applied machine-learning algorithms to categorize EEG emotional states in PD patients that would classify six basic emotions (happiness and sadness, fear, anger, surprise and disgust) in comparison with healthy controls (HC). Emotional EEG data were recorded from 20 PD patients and 20 healthy age-, education level- and sex-matched controls using multimodal (audio-visual) stimuli. The use of nonlinear features motivated by the higher-order spectra (HOS) has been reported to be a promising approach to classify the emotional states. In this work, we made the comparative study of the performance of k-nearest neighbor (kNN) and support vector machine (SVM) classifiers using the features derived from HOS and from the power spectrum. Analysis of variance (ANOVA) showed that power spectrum and HOS based features were statistically significant among the six emotional states (p < 0.0001). Classification results shows that using the selected HOS based features instead of power spectrum based features provided comparatively better accuracy for all the six classes with an overall accuracy of 70.10% ± 2.83% and 77.29% ± 1.73% for PD patients and HC in beta (13-30 Hz) band using SVM classifier. Besides, PD patients achieved less accuracy in the processing of negative emotions (sadness, fear, anger and disgust) than in processing of positive emotions (happiness, surprise) compared with HC. These results demonstrate the effectiveness of applying machine learning techniques to the classification of emotional states in PD patients in a user independent manner using EEG signals. The accuracy of the system can be improved by investigating the other HOS based features. This study might lead to a practical system for noninvasive assessment of the emotional impairments associated with neurological disorders.
Emotion processing in Parkinson's disease: an EEG spectral power study

Yuvaraj R, Murugappan M, Omar MI, Ibrahim NM, Sundaraj K, Mohamad K, et al.

Int J Neurosci, 2014 Jul;124(7):491-502.
PMID: 24168328 DOI: 10.3109/00207454.2013.860527

Although an emotional deficit is a common finding in Parkinson's disease (PD), its neurobiological mechanism on emotion recognition is still unknown. This study examined the emotion processing deficits in PD patients using electroencephalogram (EEG) signals in response to multimodal stimuli.
Erythrocarpines A-E, new cytotoxic limonoids from Chisocheton erythrocarpus

Awang K, Lim CS, Mohamad K, Morita H, Hirasawa Y, Takeya K, et al.

Bioorg Med Chem, 2007 Sep 1;15(17):5997-6002.
PMID: 17576066

Five new cytotoxic limonoids, erythrocarpines A-E (1-5), were isolated from the bark of Chisocheton erythrocarpus Hiern. Chemical structures, stereochemistry, and conformation were fully elucidated and characterized by 2D NMR, MS, and computational methods.
Fulltext Induction of apoptosis in human breast cancer cells via caspase pathway by vernodalin isolated from Centratherum anthelminticum (L.) seeds

Looi CY, Arya A, Cheah FK, Muharram B, Leong KH, Mohamad K, et al.

PLoS One, 2013;8(2):e56643.
PMID: 23437193 DOI: 10.1371/journal.pone.0056643

Centratherum anthelminticum (L.) seeds (CA) is a well known medicinal herb in Indian sub-continent. We recently reported anti-oxidant property of chloroform fraction of Centratherum anthelminticum (L.) seeds (CACF) by inhibiting tumor necrosis factor-α (TNF-α)-induced growth of human breast cancer cells. However, the active compounds in CACF have not been investigated previously.
Fulltext Induction of apoptosis in melanoma A375 cells by a chloroform fraction of Centratherum anthelminticum (L.) seeds involves NF-kappaB, p53 and Bcl-2-controlled mitochondrial signaling pathways

Looi CY, Moharram B, Paydar M, Wong YL, Leong KH, Mohamad K, et al.

BMC Complement Altern Med, 2013;13:166.
PMID: 23837445 DOI: 10.1186/1472-6882-13-166

Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica; black cumin) is one of the ingredients of an Ayurvedic preparation, called "Kayakalp", commonly applied to treat skin disorders in India and Southeast Asia. Despite its well known anti-inflammatory property on skin diseases, the anti-cancer effect of C. anthelminticum seeds on skin cancer is less documented. The present study aims to investigate the anti-cancer effect of Centratherum anthelminticum (L.) seeds chloroform fraction (CACF) on human melanoma cells and to elucidate the molecular mechanism involved.

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