Displaying publications 1 - 20 of 38 in total

Abstract:
Sort:
  1. Teh SS, Ahmad R, Wan-Abdullah WN, Liong MT
    J Agric Food Chem, 2009 Nov 11;57(21):10187-98.
    PMID: 19821558 DOI: 10.1021/jf902003a
    The objective of this study was to evaluate agricultural wastes as immobilizers for probiotics in liquid foods, such as soy milk. Probiotic strains were initially evaluated for acid and bile tolerance and the ability to produce alpha-galactosidase. Rinds of durian, mangosteen, and jackfruit were dried, ground, and sterilized prior to immobilization of selected strains ( Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733, and Lactobacillus bulgaricus FTCC 0411). Immobilized cells were inoculated into soy milk, and growth properties were evaluated over 168 h at 37 degrees C. Soy milk containing free cells without agrowastes was used as the control. Immobilized probiotics showed increased growth, greater reduction of stachyose, sucrose, and glucose, higher production of lactic and acetic acids, and lower pH in soy milk compared to the control. The results illustrated that agrowastes could be used for the immobilization of probiotics with enhanced growth, utilization of substrates, and production of organic acids.
  2. Teh SS, Ahmad R, Wan-Abdullah WN, Liong MT
    J Food Sci, 2010 Apr;75(3):M155-64.
    PMID: 20492305 DOI: 10.1111/j.1750-3841.2010.01538.x
    Cell immobilization is an alternative to microencapsulation for the maintenance of cells in a liquid medium. The objective of this study was to evaluate the effects of agrowastes from durian (Durio zibethinus), cempedak (Artocarpus champeden), and mangosteen (Garcinia mangostana) as immobilizers for lactobacilli grown in soymilk. Rinds from the agrowastes were separated from the skin, dried, and ground (150 microm) to form powders and used as immobilizers. Scanning electron microscopy revealed that lactobacilli cells were attached and bound to the surface of the immobilizers. Immobilized cells of Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733, and L. bulgaricus FTCC 0411 were inoculated into soymilk, stored at room temperature (25 degrees C) and growth properties were evaluated over 168 h. Soymilk inoculated with nonimmobilized cells was used as the control. Utilization of substrates, concentrations of lactic and acetic acids, and changes in pH were evaluated in soymilk over 186 h. Immobilized lactobacilli showed significantly better growth (P < 0.05) compared to the control, accompanied by higher production of lactic and acetic acids in soymilk. Soymilk containing immobilized cells showed greater reduction of soy sugars such as stachyose, raffinose, sucrose, fructose, and glucose compared to the control (P < 0.05).
  3. Ee GC, Teh SS, Mah SH, Rahmani M, Taufiq-Yap YH, Awang K
    Molecules, 2011 Aug 25;16(9):7249-55.
    PMID: 21869752 DOI: 10.3390/molecules16097249
    Our ongoing investigations on the stem bark of Mesua beccariana afforded a novel cyclodione coumarin, beccamarin, together with two known xanthones, mesuarianone, mesuasinone, two anthraquinones, 4-methoxy-1,3,5-trihydroxy-anthraquinone and 2,5-dihydroxy-1,3,4-trimethoxyanthraquinone and one coumarin, mammea A/AB. The structures were elucidated by 1D and 2D NMR and MS techniques.
  4. Ee GC, Mah SH, Kwong HC, Teh SS, Mohamed Tahir MI, Silong S
    Acta Crystallogr Sect E Struct Rep Online, 2011 Oct 1;67(Pt 10):o2607-8.
    PMID: 22064829 DOI: 10.1107/S1600536811036294
    THE TITLE COMPOUND [SYSTEMATIC NAME: 5,10-di-hy-droxy-2,2-di-methyl-12-(2-methyl-but-3-en-2-yl)-pyrano[3,2-b]xanthen-6(2H)-one], C(23)H(22)O(5), isolated from the stem bark of Calophyllum soulattri, consists of four six-membered rings and a 2-methyl-but-3-en-2-yl side chain. The tricyclic xanthone ring system is almost planar [maximum deviation = 0.093 (2) Å], whereas the pyran-oid ring is in a distorted boat conformation. The 2-methyl-but-3-en-2-yl side chain is in a synperiplanar conformation. There are two intra-molecular O-H⋯O hydrogen bonds. In the crystal, mol-ecules are linked by C-H⋯O inter-actions, forming a zigzag chain propagating in [010].
  5. Ee GC, Mah SH, Rahmani M, Taufiq-Yap YH, Teh SS, Lim YM
    J Asian Nat Prod Res, 2011 Oct;13(10):956-60.
    PMID: 21972812 DOI: 10.1080/10286020.2011.600248
    The stem bark extracts of Calophyllum inophyllum furnished one new furanoxanthone, inophinnin (1), in addition to inophyllin A (2), macluraxanthone (3), pyranojacareubin (4), 4-hydroxyxanthone, friedelin, stigmasterol, and betulinic acid. The structures of these compounds were determined by spectroscopic analysis of 1D and 2D NMR spectral data ((1)H, (13)C, DEPT, COSY, HMQC, and HMBC) while EI-MS gave the molecular mass. The new xanthone, inophinnin (1), exhibited some anti-inflammatory activity in nitric oxide assay.
  6. Ee GC, Mah SH, Teh SS, Rahmani M, Go R, Taufiq-Yap YH
    Molecules, 2011 Nov 23;16(11):9721-7.
    PMID: 22113580 DOI: 10.3390/molecules16119721
    The extracts of the stem bark of Calophyllum soulattri gave a new pyranocoumarin, soulamarin (1), together with five other xanthones caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), trapezifolixanthone (5) and brasixanthone B (6) one common triterpene, friedelin (7), and the steroidal triterpene stigmasterol (8). The structures of these compounds were established based on spectral evidence (1D and 2D NMR).
  7. Mah SH, Ee GC, Teh SS, Rahmani M, Lim YM, Go R
    Molecules, 2012 Jul 10;17(7):8303-11.
    PMID: 22781442 DOI: 10.3390/molecules17078303
    Our continuing studies on secondary metabolites from the stem bark of Calophyllum soulattri has led to the isolation of another new diprenylated xanthone, phylattrin (1), in addition to five other xanthones and two common sterols. The xanthones are soulattrin (2), caloxanthone C (3), macluraxanthone (4), brasixanthone B (5) and trapezifolixanthone (6) while the sterols are stigmasterol (7) and β-sitosterol (8). The structures of these compounds were determined on the basis of spectroscopic analyses such as 1D and 2D-NMR, HRESIMS, IR and UV. Compounds 1-7 exhibited moderate cytotoxic activities against SNU-1, HeLa, Hep G2, NCI-H23, K562, Raji, LS174T, IMR-32 and SK-MEL-28 cells.
  8. Teh SS, Cheng Lian Ee G, Mah SH, Lim YM, Rahmani M
    Molecules, 2012 Sep 10;17(9):10791-800.
    PMID: 22964497 DOI: 10.3390/molecules170910791
    An investigation on biologically active secondary metabolites from the stem bark of Mesua beccariana was carried out. A new cyclodione, mesuadione, along with several known constituents which are beccamarin, 2,5-dihydroxy-1,3,4-trimethoxy anthraquinone, 4-methoxy-1,3,5-trihydroxyanthraquinone, betulinic acid and stigmasterol were obtained from this ongoing research. Structures of these compounds were elucidated by extensive spectroscopic methods, including 1D and 2D-NMR, GC-MS, IR and UV techniques. Preliminary tests of the in vitro cytotoxic activities of all the isolated metabolites against a panel of human cancer cell lines Raji (lymphoma), SNU-1 (gastric carcinoma), K562 (erythroleukemia cells), LS-174T (colorectal adenocarcinoma), HeLa (cervical cells), SK-MEL-28 (malignant melanoma cells), NCI-H23 (lung adenocarcinoma), IMR-32 (neuroblastoma) and Hep-G2 (hepatocellular liver carcinoma) were carried out using an MTT assay. Mesuadione, beccamarin, betulinic acid and stigmasterol displayed strong inhibition of Raji cell proliferation, while the proliferation rate of SK-MEL-28 and HeLa were strongly inhibited by stigmasterol and beccamarin, indicating these secondary metabolites could be anti-cancer lead compounds in drug discovery.
  9. Teh SS, Ee GC, Mah SH, Lim YM, Ahmad Z
    Molecules, 2013 Feb 04;18(2):1985-94.
    PMID: 23381024 DOI: 10.3390/molecules18021985
    The cytotoxic structure-activity relationships among a series of xanthone derivatives from Mesua beccariana, Mesua ferrea and Mesua congestiflora were studied. Eleven xanthone derivatives identified as mesuarianone (1), mesuasinone (2), mesuaferrin A (3), mesuaferrin B (4), mesuaferrin C (5), 6-deoxyjacareubin (6), caloxanthone C (7), macluraxanthone (8), 1,5-dihydroxyxanthone (9), tovopyrifolin C (10) and α-mangostin (11) were isolated from the three Mesua species. The human cancer cell lines tested were Raji, SNU-1, K562, LS-174T, SK-MEL-28, IMR-32, HeLa, Hep G2 and NCI-H23. Mesuaferrin A (3), macluraxanthone (8) and α-mangostin (11) showed strong cytotoxicities as they possess significant inhibitory effects against all the cell lines. The structure-activity relationship (SAR) study revealed that the diprenyl, dipyrano and prenylated pyrano substituent groups of the xanthone derivatives contributed towards the cytotoxicities.
  10. Teh SS, Ee GC, Mah SH, Yong YK, Lim YM, Rahmani M, et al.
    Biomed Res Int, 2013;2013:517072.
    PMID: 24089682 DOI: 10.1155/2013/517072
    The in vitro cytotoxicity tests on the extracts of Mesua beccariana, M. ferrea, and M. congestiflora against Raji, SNU-1, HeLa, LS-174T, NCI-H23, SK-MEL-28, Hep-G2, IMR-32, and K562 were achieved using MTT assay. The methanol extracts of Mesua beccariana showed its potency towards the proliferation of B-lymphoma cell (Raji). In addition, only the nonpolar to semipolar extracts (hexane to ethyl acetate) of the three Mesua species indicated cytotoxic effects on the tested panel of human cancer cell lines. Antioxidant assays were evaluated using DPPH scavenging radical assay and Folin-Ciocalteu method. The methanol extracts of M. beccariana and M. ferrea showed high antioxidant activities with low EC₅₀ values of 12.70 and 9.77  μg/mL, respectively, which are comparable to that of ascorbic acid (EC₅₀ = 5.62  μg/mL). Antibacterial tests were carried out using four Gram positive and four Gram negative bacteria on Mesua beccariana extracts. All the extracts showed negative results in the inhibition of Gram negative bacteria. Nevertheless, methanol extracts showed some activities against Gram positive bacteria which are Bacillus cereus, methicillin-sensitive Staphylococcus aureus (MSSA), and methicillin-resistant Staphylococcus aureus (MRSA), while the hexane extract also contributed some activities towards Bacillus cereus.
  11. Teh SS, Ahem A, Bastion ML
    BMJ Case Rep, 2013;2013.
    PMID: 23774706 DOI: 10.1136/bcr-2013-009697
    This paper describes a rare case of Coats disease with late presentation in a young adult. The condition improved with a combination of focal photocoagulation, cryotherapy and intravitreal ranibizumab.
  12. Yong YK, Tan JJ, Teh SS, Mah SH, Ee GC, Chiong HS, et al.
    PMID: 23533485 DOI: 10.1155/2013/462751
    Clinacanthus nutans Lindau leaves (CN) have been used in traditional medicine but the therapeutic potential has not been explored for cancer prevention and treatment. Current study aimed to evaluate the antioxidant and antiproliferative effects of CN, extracted in chloroform, methanol, and water, on cancer cell lines. Antioxidant properties of CN were evaluated using DPPH, galvinoxyl, nitric oxide, and hydrogen peroxide based radical scavenging assays, whereas the tumoricidal effect was tested on HepG2, IMR32, NCL-H23, SNU-1, Hela, LS-174T, K562, Raji, and IMR32 cancer cells using MTT assay. Our data showed that CN in chloroform extract was a good antioxidant against DPPH and galvinoxyl radicals, but less effective in negating nitric oxide and hydrogen peroxide radicals. Chloroform extract exerted the highest antiproliferative effect on K-562 (91.28 ± 0.03%) and Raji cell lines (88.97 ± 1.07%) at 100  μ g/ml and the other five cancer cell lines in a concentration-dependent manner, but not on IMR-32 cells. Fourteen known compounds were identified in chloroform extract, which was analysed by gas chromatography-mass spectra analysis. In conclusion, CN extracts possess antioxidant and antiproliferative properties against cultured cancer cell lines, suggesting an alternate adjunctive regimen for cancer prevention or treatment.
  13. See I, Ee GC, Teh SS, Kadir AA, Daud S
    Molecules, 2014 Jun 04;19(6):7308-16.
    PMID: 24901833 DOI: 10.3390/molecules19067308
    A detailed chemical study on the ethyl acetate and methanol extracts of the stem bark of Garcinia mangostana resulted in the successful isolation of one new prenylated xanthone, mangaxanthone B (1), one new benzophenone, mangaphenone (2), and two known xanthones, mangostanin (3) and mangostenol (4). The structures of these compounds were elucidated through analysis of their spectroscopic data obtained using 1D and 2D NMR and MS techniques.
  14. Daud SB, Ee GC, Malek EA, Teh SS, See I
    Nat Prod Res, 2014;28(19):1534-8.
    PMID: 24897077 DOI: 10.1080/14786419.2014.924001
    A new coumarin, hoseimarin (1), together with four other xanthones, trapezifolizanthone (2), osajaxanthone (3), β-mangostin (4) and caloxanthone A (5), were isolated from the stem bark of Calophyllum hosei. The structures of these compounds were established by using spectroscopic analysis which included (1)H NMR, (13)C NMR, COSY, DEPT, HMQC and HMBC experiments.
  15. Ee GC, See I, Teh SS, Daud S
    J Asian Nat Prod Res, 2014;16(7):790-4.
    PMID: 24670077 DOI: 10.1080/10286020.2014.901313
    Our phytochemical study on the stem bark of Garcinia mangostana has led to the discovery of a new furanoxanthone, mangaxanthone A (1), together with five known analogs. The five known analogs that were isolated are α-mangostin (2), β-mangostin (3), cowagarcinone B (4), and dulcisxanthone F (5). The structural elucidations of these compounds were carried out by interpreting their spectroscopic data, mainly 1D and 2D NMR spectra and MS.
  16. Mah SH, Lian Ee GC, Teh SS, Sukari MA
    Pak J Pharm Sci, 2015 Mar;28(2):425-9.
    PMID: 25730799
    Structure-activity relationships of eleven xanthones were comparatively predicted for four cancer cell lines after the compounds were subjected to antiproliferative assay against B-lymphocyte cells (Raji), colon carcinoma cells (LS174T), human neuroblastoma cells (IMR-32) and skin carcinoma cells (SK-MEL-28). The eleven chemical constituents were obtained naturally from the stem bark of Calophyllum inophyllum and Calophyllum soulattri. Inophinnin (1) and inophinone (2) were isolated from Calophyllum inophyllum while soulattrin (3) and phylattrin (4) were found from Calophyllum soulattri. The other xanthones were from both Calophyllum sp. and they are pyranojacareubin (5), rheediaxanthone A (6), macluraxanthone (7), 4-hydroxyxanthone (8), caloxanthone C (9), brasixanthone B (10) and trapezifolixanthone (11). Compound 3 was found to be the most cytotoxic towards all the cancer cell lines with an IC50 value of 1.25μg/mL while the simplest xanthone, compound 8 was inactive.
  17. Mah SH, Ee GC, Teh SS, Sukari MA
    Nat Prod Res, 2015;29(1):98-101.
    PMID: 25229947 DOI: 10.1080/14786419.2014.959949
    Extensive chromatographic isolation and purification of the extracts of the stem bark of Calophyllum inophyllum and Calophyllum soulattri have resulted in 11 xanthones. C. inophyllum gave inophinnin (1), inophinone (2), pyranojacareubin (5), rheediaxanthone A (6), macluraxanthone (7) and 4-hydroxyxanthone (8), while C. soulattri afforded soulattrin (3), phylattrin (4), caloxanthone C (9), brasixanthone B (10) and trapezifolixanthone (11). The structures of these compounds were determined on the basis of spectroscopic analyses such as 1D and 2D NMR, GC-MS, IR and UV. Cytotoxicity screening (MTT assay) carried out in vitro on all the xanthones using five human cancer cell lines indicated good activities for some of these xanthones. The structure-activity relationship study revealed that the inhibitory activities exhibited by these xanthone derivatives to be closely related to the existence and nature of the pyrano and the prenyl substituent groups on their skeleton.
  18. Bin Ismail AA, Ee GC, Bin Daud S, Teh SS, Hashim NM, Awang K
    J Asian Nat Prod Res, 2015;17(11):1104-8.
    PMID: 26023810 DOI: 10.1080/10286020.2015.1047353
    A new pyranoxanthone, venuloxanthone (1), was isolated from the stem bark of Calophyllum venulosum, together with three other xanthones, tovopyrifolin C (2), ananixanthone (3) and caloxanthone I (4), along with two common triterpenes, friedelin (5) and lupeol (6). The structures of these compounds were identified using several spectroscopic analyses which are NMR, GCMS and FTIR experiments.
  19. Ho HC, Liew OH, Teh SS, Hanizasurana H, Ibrahim M, Shatriah I
    Clin Ophthalmol, 2015;9:553-6.
    PMID: 25848206 DOI: 10.2147/OPTH.S82204
    Rhino-orbital-cerebral mucormycosis (ROCM) is an uncommon but fatal fungal infection. We report a rare case of unilateral ROCM with ipsilateral central retinal artery occlusion and contralateral choroiditis, which later progressed to endogenous fungal endophthalmitis. The patient was successfully treated with sinuses debridement, systemic liposomal amphotericin B, and intravitreal amphotericin B. The endophthalmitis completely resolved with good vision, but the ROCM eye remained blind due to central retinal artery occlusion.
  20. Karunakaran T, Ee GC, Teh SS, Daud S, Mah SH, Lim CK, et al.
    Nat Prod Res, 2016 Jul;30(14):1591-7.
    PMID: 26710827 DOI: 10.1080/14786419.2015.1120727
    A new alkylated coumarin derivative, hexapetarin (1) along with three other xanthones, trapezifolixanthone (2), cudraxanthone G (3) and 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (4), and four common triterpenoids, friedelin (5), stigmasterol (6), beta-sitosterol (7) and gamma-sitosterol (8) were isolated from the stem bark of Mesua hexapetala (Clusiaceae), a plant, native to Malaysia. The structures of these compounds were elucidated and determined using spectroscopic techniques such as NMR and MS. Anti-inflammatory activity assay indicated hexapetarin (1) to possess moderate anti-inflammatory activity, while 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (4) gave very good activity.
Filters
Contact Us

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

External Links