Displaying publications 61 - 80 of 103 in total

Abstract:
Sort:
  1. 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.
  2. Idris A, Abdullah Z, Ariffin A, Fairuz ZA, Ng SW, Tiekink ER
    PMID: 21588631 DOI: 10.1107/S1600536810031260
    The quinoxaline system in the title hydrate, C(15)H(13)N(3)·H(2)O, is roughly planar, the r.m.s. deviation for the 18 non-H atoms being 0.188 Å; this conformation features a short intra-molecular C-H⋯N(pyrazine) inter-action. In the crystal, the amine H atom forms an N-H⋯O hydrogen bond to the water mol-ecule, which in turn forms two O-H⋯N hydrogen bonds to the pyrazine N atoms of different organic mol-ecules. These inter-actions lead to supra-molecular arrays in the bc plane that are two mol-ecules thick; additional π-π inter-actions stabilize the layers [ring centroid-centroid distance = 3.5923 (7) Å]. The layers stack along the a-axis direction via C-H⋯π contacts.
  3. Aiyub Z, Badaruddin E, Abdullah Z, Fairuz ZA, Ng SW, Tiekink ER
    PMID: 21588567 DOI: 10.1107/S1600536810034033
    In the centrosymmetric title mol-ecule, [Cu(2)(CH(3)COO)(4)(C(6)H(9)N(3))(2)], each of the four acetate groups bridges a pair of Cu(II) atoms [Cu-Cu = 2.6540 (4) Å]. The distorted octa-hedral geometry of the metal atom is completed by an N-donor atom of the N-ethyl-pyrimidin-2-amine ligand: an intra-molecular N-H⋯O hydrogen links its N-H group to an acetate carboxyl-ate O atom. In the crystal, C-H⋯O inter-actions link the mol-ecules into a supra-molecular chain along the b axis.
  4. Nasir SB, Abdullah Z, Mainal A, Fairuz ZA, Ng SW, Tiekink ER
    PMID: 21588653 DOI: 10.1107/S1600536810031946
    In the title compound, C(11)H(10)N(2)O(2), the aromatic rings are almost orthogonal to each other [dihedral angle = 86.97 (8)°], with the benzene ring orientated to face one of the pyrazine N atoms. In the crystal, centrosymmetrically related pairs are connected via pairs of C-H⋯π inter-actions and the dimeric units thus formed pack into undulating layers that stack along the a axis.
  5. Nasir SB, Abdullah Z, Fairuz ZA, Ng SW, Tiekink ER
    PMID: 21588583 DOI: 10.1107/S1600536810030448
    The pyrimidine and benzene rings in the title compound, C(10)H(8)N(2)O(2), form a dihedral angle of 71.03 (7)°, with the roughly orthogonal benzene ring being folded towards one of the pyrimidine N atoms. In the crystal, pairs of O-H⋯N hydrogen bonds connect mol-ecules related by twofold symmetry into dimeric aggregates. These associate into a supra-molecular chain propagating along the b axis by way of C-H⋯π contacts. The chains are cross-linked by π-π inter-actions that occur between pyrimidine rings [ring centroid-centroid distances = 3.5393 (9) and 3.5697 (9) Å].
  6. Fairuz ZA, Aiyub Z, Abdullah Z, Ng SW, Tiekink ER
    PMID: 21588477 DOI: 10.1107/S1600536810030187
    In the crystal structure of the title complex, [Cu(2)(CH(3)COO)(4)(C(12)H(11)ClN(2))(2)], the complete binuclear mol-ecule is generated by a crystallographic centre of inversion; the four acetate groups each bridge a pair of Cu(II) atoms. The coordination of the metal atom is distorted octa-hedral within a donor set defined by four O atoms, the heterocyclic N atom and the second Cu atom. The pyridine ring is twisted with respect to the benzene ring, forming a dihedral angle of 33.9 (2)°. An intra-molecular N-H⋯O hydrogen bond is present between the amino group and a carboxyl O atom. Inter-molecular inter-actions of the C-H⋯π type link mol-ecules in the crystal structure.
  7. Fairuz ZA, Aiyub Z, Abdullah Z, Ng SW, Tiekink ER
    PMID: 21588497 DOI: 10.1107/S1600536810031168
    The title complex, [Cu(2)(CH(3)COO)(4)(C(13)H(14)N(2))(2)], features a binuclear mol-ecule, which lies about a crystallographic centre of inversion; the four acetate ions each bridge a pair of Cu(II) atoms. The coordination of the metal atom is distorted octa-hedral within a donor set defined by four O atoms, the heterocyclic N atom and the second Cu atom. The pyridine ring is twisted with respect to the tolyl ring and forms a dihedral angle of 35.34 (9)°. A bifurcated N-H⋯(O,O) hydrogen bond is present, linking the amine group to two carboxyl-ate O atoms derived from different acetate ions. In the crystal, C-H⋯π inter-actions link mol-ecules into a supra-molecular array in the bc plane.
  8. Nasir SB, Abdullah Z, Fairuz ZA, Ng SW, Tiekink ER
    PMID: 21588464 DOI: 10.1107/S160053681003014X
    In the title compound, C(11)H(10)N(2)O(2), the benzene ring faces towards one of the pyrimidine N atoms, and is almost orthogonal to the plane through the pyrimidine ring [dihedral angle = 84.40 (14)°]. In the crystal, the presence of C-H⋯π and π-π [centroid-centroid separation = 3.7658 (18) Å] inter-actions leads to a supra-molecular array in the ac plane. The layers thus formed inter-digitate along the b axis.
  9. Fairuz ZA, Aiyub Z, Abdullah Z, Ng SW, Tiekink ER
    PMID: 21588463 DOI: 10.1107/S1600536810030138
    In the title compound, C(12)H(11)ClN(2), the dihedral angle between the benzene and pyridyl rings is 48.03 (8)°. Twists are also evident in the mol-ecule, in particular about the N(a)-C(b) (a = amine and b = benzene) bond [C-N-C-C = -144.79 (18)°]. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds result in the formation of eight-membered {⋯NCNH}(2) synthons [or R(2) (2)(8) loops].
  10. Wan Saffiee WA, Idris A, Aiyub Z, Abdullah Z, Ng SW
    PMID: 21581408 DOI: 10.1107/S160053680803729X
    The two aromatic systems in the title compound, C(11)H(11)N(3), are inclined by 19.1 (1)°, whilst the angle at the central amino N atom is 130.3 (2)°. The amino group forms a hydrogen bond to the pyrazine N-4 atom of an adjacent mol-ecule, forming a chain motif.
  11. Wan Saffiee WA, Idris A, Aiyub Z, Abdullah Z, Ng SW
    PMID: 21581405 DOI: 10.1107/S1600536808038658
    There are two mol-ecules in the asymmetric unit of the title compound, C(11)H(9)ClN(2), with dihedral angles of 41.84 (12) and 49.24 (12)° between the aromatic ring planes. The two mol-ecules form a dimer via a pair of N-H⋯N hydrogen bonds.
  12. Idris A, Wan Saffiee WA, Abdullah Z, Ariffin A, Ng SW
    PMID: 21581411 DOI: 10.1107/S1600536808038610
    There are two mol-ecules in the asymmetric unit of the title compound, C(14)H(10)ClN(3), with dihedral angles of 5.11 (10) and 13.61 (10)° between the aromatic ring systems. In the crystal structure, mol-ecules are linked by N-H⋯N hydrogen bonds, resulting in chains propagating in [010].
  13. Wan Saffiee WA, Idris A, Abdullah Z, Aiyub Z, Ng SW
    PMID: 21580969 DOI: 10.1107/S1600536808031942
    The two aromatic rings in the title compound, C(10)H(9)N(3), are inclined at 15.2 (1)° to each other; this opens up the angle at the amino N atom to 130.4 (1)°. The amino N atom forms a hydrogen bond to the 4-N atom of an adjacent mol-ecule to create a chain motif.
  14. Wan Saffiee WA, Idris A, Aiyub Z, Abdullah Z, Ng SW
    PMID: 21581575 DOI: 10.1107/S1600536808041172
    In the title compound, C(10)H(8)ClN(3), the dihedral angle between the aromatic rings is 43.0 (1)° and the bridging C-N-C angle is 128.19 (16)°. The amino N atom of one mol-ecule forms a hydrogen bond to the 1-N atom of an adjacent pyrazinyl ring, generating an inversion dimer.
  15. Lim SH, Sim KM, Abdullah Z, Hiraku O, Hayashi M, Komiyama K, et al.
    J Nat Prod, 2007 Aug;70(8):1380-3.
    PMID: 17608533
    Four new indole alkaloids were obtained from two Kopsia species, 6-oxoleuconoxine (1) from the leaf extract of K. griffithii and kopsinitarine E (2), kopsijasminine (3), and kopsonoline (4) from the stem-bark extract of K. teoi. The structures of these alkaloids were determined using NMR and MS analysis. Kopsijasminine (3) showed moderate activity in reversing multidrug resistance in vincristine-resistant KB cells.
  16. Lim SH, Low YY, Subramaniam G, Abdullah Z, Thomas NF, Kam TS
    Phytochemistry, 2013 Mar;87:148-56.
    PMID: 23200029 DOI: 10.1016/j.phytochem.2012.11.005
    Lumusidines A-D, bisindole alkaloids of the macroline-macroline type, and one of the macroline-pleiocarpamine type, villalstonidine F, were isolated from the stem-bark extract of Alstonia macrophylla (Apocynaceae). The structures and absolute configurations of these alkaloids were established using NMR, MS, and X-ray diffraction analyses.
  17. Muhamad Sarih N, Myers P, Slater A, Slater B, Abdullah Z, Tajuddin HA, et al.
    Sci Rep, 2019 08 14;9(1):11834.
    PMID: 31413269 DOI: 10.1038/s41598-019-47847-5
    Three fluorescent organic compounds-furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)-are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d'Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.
  18. Le CF, Kailaivasan TH, Chow SC, Abdullah Z, Ling SK, Fang CM
    Int Immunopharmacol, 2017 Mar;44:203-210.
    PMID: 28119186 DOI: 10.1016/j.intimp.2017.01.013
    Clinacanthus nutans (Burm. f.) Lindau is a traditional medicinal plant belonging to the Acanthaceae family. Its therapeutic potentials have been increasingly documented particularly the antiviral activity against Herpes Simplex Virus (HSV), anti-cancer, anti-oxidant, anti-inflammatory and immunomodulatory activities. However, majority of these studies used crude or fractionated extracts and not much is known about individual compounds from these extracts and their biological activities. In the present study, we have isolated four compounds (CN1, CN2, CN3 and CN4) from the hexane fractions of C. nutans leaves. Using NMR spectroscopic analysis, these compounds were identified to be shaftoside (CN1), stigmasterol (CN2), β-sitosterol (CN3) and a triterpenoid lupeol (CN4). To determine the immunosuppressive potential of these compounds, their effects on mitogens induced T and B lymphocyte proliferation and the secretion of helper T cell cytokines were examined. Among the four compounds, stigmasterol (CN2) and β-sitosterol (CN3) were shown to readily inhibit T cell proliferation mediated by Concanavalin A (ConA). However, only β-sitosterol (CN3) and not stigmasterol (CN2) blocks the secretion of T helper 2 (Th2) cytokines (IL-4 and IL-10). Both compounds have no effect on the secretion of Th1 cytokines (IL-2 and IFN-γ), suggesting that β-sitosterol treatment selectively suppresses Th2 activity and promotes a Th1 bias. CN3 was also found to significantly reduce the proliferation of both T helper cells (CD4(+)CD25(+)) and cytotoxic T cells (CD8(+)CD25(+)) following T cell activation induced by ConA. These results suggested that phytosterols isolated from C. nutans possess immunomodulatory effects with potential development as immunotherapeutics.
  19. Abdullah Z, Abdul Aziz SH, Sodri NA, Mohd Hanafiah AN, Ibrahim NI, Johari MZ
    J Prim Care Community Health, 2020 10 23;11:2150132720956478.
    PMID: 33089737 DOI: 10.1177/2150132720956478
    BACKGROUND: Primary healthcare is the earliest gateway for patient care, and improvisations are often needed to accommodate the ever-increasing demand in public health. The Enhanced Primary Healthcare (EnPHC) initiative is aimed at improving such needs, and one core intervention is the introduction of a care coordinator (CC). The purpose of this study was to identify barriers and facilitators in implementing a new intervention in primary healthcare clinics.

    METHODS: This qualitative exploration study. All healthcare providers who were involved in EnPHC at the intervention clinics were selected as participants. In-depth interviews and focus group discussions were carried out among healthcare providers working in the intervention clinic. Thematic analysis was used to categorize data, based on the consolidated framework for implementation research (CFIR) theoretical framework domains.

    RESULTS: A total of 61 healthcare providers participated. All 5 domains with 19 CFIR constructs emerged from the analysis. Inner setting played a significant role in facilitating CC intervention, in which culture, networking, and collaboration and leadership engagement played an essential role in supporting CC activities. Although CC tasks are complex, concerns of losing clinical skill and resource constraints were identified as potential barriers in CC implementations. Criteria for appointing new CCs emerged from the characteristics of individual constructs, in which the individual must be familiar and interested in community health, have good communication skills, and at least 3 years' experience in the primary healthcare setting.

    CONCLUSION: The implementation of the CC intervention faces varying challenges in different settings. This is partially resolved through teamwork, guidance from mentors, and support from superiors. The complexity of the responsibility of the CC intervention is perceived as both a validation and a burden. Above all, it is seen as paramount in EnPHC intervention.

  20. Tay YL, Abdullah Z, Chelladorai K, Low LL, Tong SF
    PMID: 34444527 DOI: 10.3390/ijerph18168778
    Malaysia implemented its first Movement Control Order (MCO) during the early phase of the COVID-19 pandemic to slow the transmission of the virus. This study aimed to explore the public perception of the MCO implementation and people's experiences during this period. The study employed qualitative explorative in-depth interviews conducted with 23 Malaysian adults from various demographic backgrounds. Thematic analysis was performed using NVivo 12. Three main themes were identified: a period of information surge, heterogeneous emotional response, and attempts to adapt. During the MCO, the participants obtained information from multiple platforms. They suggested the need for clear and repeated instructions to avoid confusion and misinformation. They also acknowledged the importance of the MCO in breaking the chain of transmission and safeguarding high-risk groups; however, they also expressed that stricter enforcement from the authorities was warranted. The changes in the participants' work-life routines, lack of physical interaction, and uncertainty about their health and the economy due to the MCO negatively impacted their psychological states. Despite these challenges, the participants attempted to adapt to life under the MCO in different ways. The findings imply that during a crisis, the public tends to seek clear and reliable information, experience emotional turmoil, and adapt to changes. The MCO implementation can be improved through an effective communication strategy and efforts to battle misinformation.
Filters
Contact Us

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

External Links