Displaying publications 1 - 20 of 80 in total

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  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.
  2. Ketuly KA, Hadi AH, Ng SW, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2011 Apr 1;67(Pt 4):o773-4.
    PMID: 21754066 DOI: 10.1107/S1600536811007306
    Two independent mol-ecules comprise the asymmetric unit of the title cholestane derivative, C(29)H(49)NO(3) {systematic name: (3S,8S,9S,10R,13R,14S,17R)-17-[(1R)-1,5-dimethyl-hex-yl]-6-hy-droxy-imino-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetra-deca-hydro-1H-cyclo-penta-[a]phenanthren-3-yl ace-tate}. The major differences between the mol-ecules relate to the relative orientations of the terminal acetyl [C-C-O-C torsion angles = -158.8 (3) and -81.7 (3)°] and alkyl groups [C-C-C-C = 168.9 (3) and 65.8 (4)°]. In the crystal, the independent mol-ecules associate via pairs of O-H⋯N hydrogen bonds, forming dimeric aggregates. Supra-molecular layers in the ab plane are mediated by C-H⋯O inter-actions.
  3. Ahmed Hamdi OA, Awang K, Hadi AH, Syamsir DR, Ng SW
    PMID: 21589030 DOI: 10.1107/S1600536810040559
    The title compound, systematic name 9-isopropyl-idene-2,6-dimethyl-11-oxatricyclo-[6.2.1.0(1,5)]undec-6-en-8-ol, C(15)H(22)O(2), which crystallizes with two mol-ecules of similar conformation in the asymmetric unit, features three fused rings, two of which are five-membered and the third six-membered. Of the two five-membered rings, the one with an O atom has a distinct envelope shape (with the O atom representing the flap). The six-membered ring is also envelope-shaped as it shares a common O atom with the five-membered ring. In the crystal, the two independent mol-ecules are linked by a pair of O-H⋯O hydrogen bonds, generating a dimer.
  4. Ketuly KA, Hadi AH, Ng SW, Tiekink ER
    PMID: 21588624 DOI: 10.1107/S160053681003117X
    In the title cholestane derivative, C(28)H(48) [systematic name: (1S,2S,7R,10R,11R,14R,15R)-2,5,10,15-tetra-methyl-14-[(2R)-6-methyl-heptan-2-yl]tetra-cyclo-[8.7.0.0(2,7).0(11,15)]hepta-dec-4-ene], the cyclo-hexene ring adopts a half-chair conformation. The parent 5α-cholest-2-ene and the equivalent fragment of the title compound are almost superimposable (r.m.s. deviation = 0.033 Å).
  5. Ketuly KA, Hadi AH, Khaledi H, Tiekink ER
    PMID: 21579426 DOI: 10.1107/S1600536810016661
    The asymmetric unit of the title compound {systematic name: (3S,8S,9S,10R,13R,14S,17R)-17-[(E,2R,5S)-5-ethyl-6-methyl-hept-3-en-2-yl]-10,13-dimethyl-2,3,4,7,8,9,11,12,14,15,16,17-dodeca-hydro-1H-cyclo-penta-[a]phenanthren-3-yl p-toluene-sulfonate}, C(36)H(54)O(3)S, comprises two independent mol-ecules that differ significantly in terms of the relative orientations of the peripheral groups; the conformation about the C=C bond of the side chain is E. In the crystal, mol-ecules associate into linear supra-molecular chains aligned along the a axis via C-H⋯O inter-actions.
  6. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21583846 DOI: 10.1107/S160053680901188X
    In the title anhydro-scymnol tetra-acetate, C(35)H(54)O(9), the fused chair conformation of the cyclo-hexane A/B ring junction is cis with a 5β-H configuration. The compound has a trimethyl-ene oxide ring at position 24,26 and four acetate groups at the 3α,7α,12α,27 positions.
  7. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21583935 DOI: 10.1107/S1600536809014597
    In the title steroid derivative, C(23)H(37)IO, the fused cyclo-propane unit that comprises part of the A ring has a β-configuration, and the associated cyclo-pentane ring has an envelope conformation.
  8. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21583934 DOI: 10.1107/S1600536809014585
    In the title compound (5S,8R,9R,10R,13S,14S,17R,20R)-24-bromo-5β-cholane, C(24)H(41)Br, the fused-chair conformation of the cyclo-hexane A/B ring junction is cis with a 5β-H configuration.
  9. Mukhtar MR, Zainal Abidin A, Awang K, A Hadi AH, Ng SW
    PMID: 21582249 DOI: 10.1107/S160053680900600X
    The mol-ecule of accanthomine A, C(15)H(13)N(5), is approximately planar, with the indolyl fused-ring and the pyrimidyl ring being twisted by 31.7 (1)° The amino group of the five-membered ring is an intramolecular hydrogen-bond donor to a nitro-gen acceptor of the pyrimide ring. The amino group of the pyrimide ring is a hydrogen-bond donor to the N atoms of adjacent mol-ecules. These hydrogen-bonding inter-actions give rise to a layered network with a 4.8(2) topology.
  10. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21582787 DOI: 10.1107/S1600536809020674
    In the title steroid derivative, C(25)H(40)O(3), the fused cyclo-propane unit that corresponds to a part of the A ring has a β-configuration and the associated cyclo-pentane ring an envelope-shaped conformation.
  11. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21583524 DOI: 10.1107/S1600536809025987
    In the crystal structure of 2-bromo-beclometasone dipropionate [systematic name: (8S,9R,10S,11S,13S,14S,16S,17R)-2-bromo-9α-chloro-11-hydr-oxy-10,13,16-trimethyl-3-oxo-17-[2-(propion-yloxy)acet-yl]-6,7,8,9,10,11,12,13,14,15,16,17-dodeca-hydro-3H-cyclo-penta-[a]phenanthren-17-yl propionate], C(28)H(36)BrClO(7), the six-membered ring with the 1,4-diene-3-one composition is planar (r.m.s. deviations = 0.03 and 0.04 Å for the two independent mol-ecules), whereas the remaining six-membered rings have chair conformations. Each of the independent mol-ecules self-associates via O-H⋯O(propionate) hydrogen bonding, generating a supra-molecular chain running along the b axis. The crystal is twinned, with the monoclinic unit cell emulating an orthorhomic crystal system; the major twin component constitutes approximately 60%.
  12. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21583523 DOI: 10.1107/S1600536809025975
    In the crystal structure of (8S,9R,10S,11S,13S,14S,16S,17R)-9α-bromo-11-hydr-oxy-10,13,16-trimethyl-3-oxo-17-[2-(propion-yloxy)acet-yl]-6,7,8,9,10,11,12,13,14,15,16,17-dodeca-hydro-3H-cyclo-penta-[a]phenanthren-17-yl propionate monohydrate, C(28)H(37)BrO(7)·H(2)O, which has a 9α-Br atom in place of the 9α-Cl atom of monohydrated beclometasone dipropionate, one six-membered ring is planar (r.m.s. deviation = 0.02 Å) owing to its 1,4-diene-3-one composition, whereas the two other six-membered rings each have a chair conformation. The organic mol-ecule and water mol-ecules engage in hydrogen-bonding inter-actions, generating a helical chain running along the c axis of the ortho-rhom-bic unit cell.
  13. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21577621 DOI: 10.1107/S1600536809028293
    The title compound, C(28)H(34)Cl(2)O(7), is a derivative of the glucocorticoid steroid beclomethasone dipropionate. It features an expoxide linkage [angle at oxygen = 96.6 (2)°]. The dichlorocyclohexenone ring adopts an envelope conformation, with the C atom bearing the two Cl substituents representing the flap. The dichloro-methyl C atom deviates by 0.471 (4) Å from the plane defined by the other five atoms, whose maximum r.m.s. deviation is 0.04 Å.
  14. Ketuly KA, A Hadi AH, Ng SW
    PMID: 21583067 DOI: 10.1107/S1600536809014603
    In the title compound, C(18)H(21)IO, the cyclo-hexane ring adopts a chair conformation, whereas the cyclo-pentane ring and the ten-membered tetra-line portions each adopt an envelope conformation. For the five-membered ring, the methine C atom deviates by 0.638 (4) Å (r.m.s. of the four other atoms is 0.005 Å) and for the ten-membered ring, the methine C atom constituting the flap deviates by 0.671 (3) Å (r.m.s. of the other nine atoms is 0.066 Å).
  15. Najmuldeen IA, Hadi AH, Awang K, Mohamad K, Ng SW
    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.
  16. Chan G, Awang K, A Hadi AH, Ng SW
    PMID: 21202956 DOI: 10.1107/S1600536808018151
    The title compound, C(30)H(34)O(5), crystallizes with two symmetry-independent mol-ecules in the asymmetric unit. In the crystal structure, the two independent mol-ecules are disposed about a pseudo-center of inversion. An intra-molecular O-H⋯O hydrogen bond is observed in each independent mol-ecule. The crystal structure is stabilized by C-H⋯O hydrogen bonds.
  17. Mukhtar MR, Nafiah MA, Awang K, A Hadi AH, Ng SW
    PMID: 21202644 DOI: 10.1107/S1600536808014451
    The hydr-oxy groups in the title compound, C(16)H(14)O(4), are each hydrogen bonded to the adjacent meth-oxy O atom; one of the two hydr-oxy groups is additionally linked to the O atom of the meth-oxy group of another mol-ecule, forming a linear chain.
  18. Ng KB, Bustamam A, Sukari MA, Abdelwahab SI, Mohan S, Buckle MJ, et al.
    PMID: 23432947 DOI: 10.1186/1472-6882-13-41
    Boesenbergia rotunda (Roxb.) Schlecht (family zingiberaceae) is a rhizomatous herb that is distributed from north-eastern India to south-east Asia, especially in Indonesia, Thailand and Malaysia. Previous research has shown that the crude extract of this plant has cytotoxic properties. The current study examines the cytotoxic properties of boesenbergin A isolated from Boesenbergia rotunda.
  19. Golbabapour S, Hajrezaie M, Hassandarvish P, Abdul Majid N, Hadi AH, Nordin N, et al.
    Biomed Res Int, 2013;2013:974185.
    PMID: 23781513 DOI: 10.1155/2013/974185
    The investigation was to evaluate gastroprotective effects of ethanolic extract of M. pruriens leaves on ethanol-induced gastric mucosal injuries in rats. Forty-eight rats were divided into 8 groups: negative control, extract control, ulcer control, reference control, and four experimental groups. As a pretreatment, the negative control and the ulcer control groups were orally administered carboxymethylcellulose (CMC). The reference control was administered omeprazole orally (20 mg/kg). The ethanolic extract of M. pruriens leaves was given orally to the extract control group (500 mg/kg) and the experimental groups (62.5, 125, 250, and 500 mg/kg). After 1 h, CMC was given orally to the negative and the extract control groups. The other groups received absolute ethanol. The rats were sacrificed after 1 h. The ulcer control group exhibited significant mucosal injuries with decreased gastric wall mucus and severe damage to the gastric mucosa. The extract caused upregulation of Hsp70 protein, downregulation of Bax protein, and intense periodic acid schiff uptake of glandular portion of stomach. Gastric mucosal homogenate showed significant antioxidant properties with increase in synthesis of PGE2, while MDA was significantly decreased. The ethanolic extract of M. pruriens leaves was nontoxic (<5 g/kg) and could enhance defensive mechanisms against hemorrhagic mucosal lesions.
  20. 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.
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