Displaying publications 1 - 20 of 46 in total

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  1. Fulltext Polymorphism of HLA and Susceptibility of Breast Cancer
    Aboulaghras S, Khalid A, Makeen HA, Alhazmi HA, Albratty M, Mohan S, et al.
    Front Biosci (Landmark Ed), 2024 Feb 05;29(2):55.
    PMID: 38420797 DOI: 10.31083/j.fbl2902055
    Breast cancer (BC) is the second most common malignancy in the world. Numerous studies have demonstrated the association between human leukocyte antigen (HLA) and cancer. The occurrence and development of BC are closely linked to genetic factors. Human leukocyte antigens G and E (HLA-G and HLA-E) are non-classical major histocompatibility complex (MHC) class I molecules. These molecules play an important role in immune surveillance by inhibiting the cytotoxic and natural killer T cells responsible for immune escape. The expression of HLA-G and HLA-E has been associated with several diseases, including tumors. The HLA system plays a key role in the escape of tumor cells from immune surveillance. This review aims to determine the correlation between BC susceptibility and HLA markers specific HLA alleles such as HLA-B07, HLA-DRB111, HLA-DRB113, and HLA-DRB115 are associated with an increased risk of developing BC. Furthermore, HLA-G mutations have been attributed to an elevated likelihood of metastasis in BC patients. Understanding the complex associations between the HLA system and BC development is critical for developing novel cancer prevention, detection, and treatment strategies. This review emphasizes the importance of analyzing HLA polymorphisms in the management of BC patients, as well as the urgent need for further research in this area.
  2. Surface Decoration of Selenium Nanoparticles by Proteins from the Culinary-Medicinal Shiitake Mushroom, Lentinus edodes (Agaricomycetes), for Enhanced Fibrinolytic Activity
    Ali SM, Raman J, Lakshmanan H, Ling TC, Phan CW, Tan YS, et al.
    Int J Med Mushrooms, 2018;20(11):1021-1030.
    PMID: 30806227 DOI: 10.1615/IntJMedMushrooms.2018028307
    Lentinus edodes (shiitake mushroom) has exhibited fibrinolytic activity. We synthesized and characterized selenium nanoparticles (SeNPs) using protein precipitated from the mushroom. We also investigated the fibrinolytic activity of the SeNPs. The proteins from a crude extract of L. edodes were recovered through the use of aqueous 2-phase separation, and these we used as the capping agent in SeNP biosynthesis. We characterized the SeNPs using UV-visible spectrophotometry, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), particle size distribution analysis, and Fourier transform infrared spectroscopy (FT-IR). The fibrinolytic capability of the SeNPs was tested through an in vitro fibrin plate assay. The UV-visible spectra showed maximal absorbance at 220 nm. FESEM images showed that the SeNPs were dispersed and did not clump. The TEM images revealed a spherical shape and average size of the SeNPs. The particle size distribution analysis confirmed the mean size of the SeNPs at 64.53 nm. A strong signal for the presence of selenium was observed in the EDX analysis. The FT-IR spectrum revealed the involvement of protein functional groups in the reduction of sel-enite. Overall, the SeNPs capped with protein from shiitake mushroom were effective as an in vitro fibrinolytic agent.
  3. Fulltext Escaping introns in COI through cDNA barcoding of mushrooms: Pleurotus as a test case
    Avin FA, Subha B, Tan YS, Braukmann TWA, Vikineswary S, Hebert PDN
    Ecol Evol, 2017 09;7(17):6972-6980.
    PMID: 28904776 DOI: 10.1002/ece3.3049
    DNA barcoding involves the use of one or more short, standardized DNA fragments for the rapid identification of species. A 648-bp segment near the 5' terminus of the mitochondrial cytochrome c oxidase subunit I (COI) gene has been adopted as the universal DNA barcode for members of the animal kingdom, but its utility in mushrooms is complicated by the frequent occurrence of large introns. As a consequence, ITS has been adopted as the standard DNA barcode marker for mushrooms despite several shortcomings. This study employed newly designed primers coupled with cDNA analysis to examine COI sequence diversity in six species of Pleurotus and compared these results with those for ITS. The ability of the COI gene to discriminate six species of Pleurotus, the commonly cultivated oyster mushroom, was examined by analysis of cDNA. The amplification success, sequence variation within and among species, and the ability to design effective primers was tested. We compared ITS sequences to their COI cDNA counterparts for all isolates. ITS discriminated between all six species, but some sequence results were uninterpretable, because of length variation among ITS copies. By comparison, a complete COI sequences were recovered from all but three individuals of Pleurotus giganteus where only the 5' region was obtained. The COI sequences permitted the resolution of all species when partial data was excluded for P. giganteus. Our results suggest that COI can be a useful barcode marker for mushrooms when cDNA analysis is adopted, permitting identifications in cases where ITS cannot be recovered or where it offers higher resolution when fresh tissue is. The suitability of this approach remains to be confirmed for other mushrooms.
  4. Fulltext Molecular divergence and species delimitation of the cultivated oyster mushrooms: integration of IGS1 and ITS
    Avin FA, Bhassu S, Tan YS, Shahbazi P, Vikineswary S
    ScientificWorldJournal, 2014;2014:793414.
    PMID: 24587752 DOI: 10.1155/2014/793414
    Identification of edible mushrooms particularly Pleurotus genus has been restricted due to various obstacles. The present study attempted to use the combination of two variable regions of IGS1 and ITS for classifying the economically cultivated Pleurotus species. Integration of the two regions proved a high ability that not only could clearly distinguish the species but also served sufficient intraspecies variation. Phylogenetic tree (IGS1+ITS) showed seven distinct clades, each clade belonging to a separate species group. Moreover, the species differentiation was tested by AMOVA and the results were reconfirmed by presenting appropriate amounts of divergence (91.82% among and 8.18% within the species). In spite of achieving a proper classification of species by combination of IGS1 and ITS sequences, the phylogenetic tree showed the misclassification of the species of P. nebrodensis and P. eryngii var. ferulae with other strains of P. eryngii. However, the constructed median joining (MJ) network could not only differentiate between these species but also offer a profound perception of the species' evolutionary process. Eventually, due to the sufficient variation among and within species, distinct sequences, simple amplification, and location between ideal conserved ribosomal genes, the integration of IGS1 and ITS sequences is recommended as a desirable DNA barcode.
  5. Fulltext Attenuation of Inflammatory Mediators (TNF-α and Nitric Oxide) and Up-Regulation of IL-10 by Wild and Domesticated Basidiocarps of Amauroderma rugosum (Blume & T. Nees) Torrend in LPS-Stimulated RAW264.7 Cells
    Chan PM, Tan YS, Chua KH, Sabaratnam V, Kuppusamy UR
    PLoS One, 2015;10(10):e0139593.
    PMID: 26427053 DOI: 10.1371/journal.pone.0139593
    Amauroderma rugosum, commonly known as "Jiǎzī" in China, is a wild mushroom traditionally used by the Chinese to reduce inflammation, to treat diuretic and upset stomach, and to prevent cancer. It is also used by the indigenous communities in Malaysia to prevent epileptic episodes and incessant crying by babies. The aim of this study was to compare the wild and domesticated basidiocarps of A. rugosum for antioxidant and in vitro anti-inflammatory effects in LPS-stimulated RAW264.7 cells. The wild basidiocarps of A. rugosum were collected from the Belum Forest, Perak, Malaysia and the domesticated basidiocarps of A. rugosum were cultivated in the mushroom house located in the University of Malaya, Kuala Lumpur, Malaysia. Both the wild and domesticated basidiocarps were subjected to ethanolic extraction and the extracts were tested for antioxidant and anti-inflammatory activities. In this study, the crude ethanolic extract of wild (WB) and domesticated (DB) basidiocarps of A. rugosum had comparable total phenolic content and DPPH scavenging activity. However, WB (EC50 = 222.90 μg/mL) displayed a better ABTS cation radical scavenging activity than DB (EC50 = 469.60 μg/mL). Both WB and DB were able to scavenge nitric oxide (NO) radical and suppress the NO production in LPS-stimulated RAW264.7 cells and this effect was mediated through the down-regulation of inducible nitric oxide synthase (iNOS) gene. In addition, both WB and DB caused down-regulation of the inflammatory gene TNF-α and the up-regulation of the anti-inflammatory gene IL-10. There was no inhibitory effect of WB and DB on nuclear translocation of NF-κB p65. In conclusion, the wild and domesticated basidiocarps of A. rugosum possessed antioxidant and in vitro anti-inflammatory properties. WB and DB inhibited downstream inflammatory mediators (TNF-α and NO) and induced anti-inflammatory cytokine IL-10 production. No inhibitory effects shown on upstream nuclear translocation of NF-κB p65. WB and DB exhibited antioxidant activity and attenuation of proinflammatory mediators and therefore, A. rugosum may serve as a potential therapeutic agent in the management of inflammation.
  6. Fulltext Amauroderma rugosum (Blume & T. Nees) Torrend: Nutritional Composition and Antioxidant and Potential Anti-Inflammatory Properties
    Chan PM, Kanagasabapathy G, Tan YS, Sabaratnam V, Kuppusamy UR
    Evid Based Complement Alternat Med, 2013;2013:304713.
    PMID: 24371454 DOI: 10.1155/2013/304713
    Amauroderma rugosum is a wild mushroom that is worn as a necklace by the indigenous communities in Malaysia to prevent fits and incessant crying by babies. The aim of this study was to investigate the nutritive composition and antioxidant potential and anti-inflammatory effects of A. rugosum extracts on LPS-stimulated RAW264.7 cells. Nutritional analysis of freeze-dried mycelia of A. rugosum (KUM 61131) from submerged culture indicated a predominant presence of carbohydrates, proteins, dietary fibre, phosphorus, potassium, and sodium. The ethanol crude extract (EE), its hexane (HF), ethyl acetate (EAF), and aqueous (AF) fractions of mycelia of A. rugosum grown in submerged culture were evaluated for antioxidant potential and anti-inflammatory effects. EAF exhibited the highest total phenolic content and the strongest antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. HF showed dose-dependent inhibition of NO production in LPS-stimulated RAW264.7 cells and NO radical scavenging activity. Gas chromatographic analysis of HF revealed the presence of ethyl linoleate and ergosterol, compounds with known anti-inflammatory properties. In conclusion, the nutritive compositions and significant antioxidant potential and anti-inflammatory effects of mycelia extracts of A. rugosum have the potential to serve as a therapeutic agent or adjuvant in the management of inflammatory disorders.
  7. Four new bioluminescent taxa of Mycena sect. Calodontes from Peninsular Malaysia
    Chew AL, Tan YS, Desjardin DE, Musa MY, Sabaratnam V
    Mycologia, 2014 Sep-Oct;106(5):976-88.
    PMID: 24891424 DOI: 10.3852/13-274
    Three new species and one new variety of bioluminescent Mycena collected from Peninsular Malaysia are described herein. All new species belong to Mycena sect. Calodontes in what is known as the Mycena pura complex. Comprehensive descriptions, photographs, illustrations and comparisons with phenetically similar species are provided. Molecular sequences data from the nuclear internal transcribed spacers (ITS-1 and ITS-2, including the 5.8S rRNA) were used to infer relationships within sect. Calodontes. Axenic cultures were obtained to provide data on culture morphology. This is the first published photographic documentation of bioluminescent basidiomes of members of Mycena sect. Calodontes. Also, this addition brings the total known bioluminescent fungi to 77 species.
  8. Fulltext Taxonomic and phylogenetic re-evaluation of Mycena illuminans
    Chew AL, Tan YS, Desjardin DE, Musa MY, Sabaratnam V
    Mycologia, 2013 Sep-Oct;105(5):1325-35.
    PMID: 23709573 DOI: 10.3852/13-009
    Mycena illuminans Henn. is described and re-evaluated based on recently collected material from peninsular Malaysia, providing comprehensive descriptions, illustrations and photographs. In addition to morphological data, axenic monokaryon and dikaryon cultures were established to provide data on culture morphology and the mating system of the species. Molecular sequences data from the nuclear large subunit (LSU) gene also are presented, confirming that M. illuminans is not a synonym of Mycena chlorophos.
  9. Fulltext Lignosus rhinocerus (Cooke) Ryvarden: A Medicinal Mushroom That Stimulates Neurite Outgrowth in PC-12 Cells
    Eik LF, Naidu M, David P, Wong KH, Tan YS, Sabaratnam V
    Evid Based Complement Alternat Med, 2012;2012:320308.
    PMID: 22203867 DOI: 10.1155/2012/320308
    A national treasure mushroom, Lignosus rhinocerus, has been used to treat variety of ailments by local and indigenous communities in Malaysia. The aim of this study was to investigate the potential of the most valuable part of L. rhinocerus, the sclerotium, on neurite outgrowth activity by using PC-12Adh cell line. Differentiated cells with one thin extension at least double the length of the cell diameter were scored positive. Our results showed that aqueous sclerotium L. rhinocerus extract induced neurite outgrowths of 24.4% and 42.1% at 20 μg/mL (w/v) of aqueous extract alone and a combination of 20 μg/mL (w/v) aqueous extract and 30 ng/mL (w/v) of NGF, respectively. Combination of NGF and sclerotium extract had additive effects and enhanced neurite outgrowth. Neuronal differentiation was demonstrated by indirect immunofluorescence of neurofilament protein. Aqueous sclerotium extract contained neuroactive compounds that stimulated neurite outgrowth in vitro. To our knowledge this is the first report on neurite-stimulating activities of L. rhinocerus.
  10. Acute Toxicity Study and the In Vitro Cytotoxicity of a Black Lingzhi Medicinal Mushroom, Amauroderma rugosum (Agaricomycetes), from Malaysia
    Fung SY, Tan NH, Kong BH, Lee SS, Tan YS, Sabaratnam V
    Int J Med Mushrooms, 2017;19(12):1093-1099.
    PMID: 29431070 DOI: 10.1615/IntJMedMushrooms.2017024550
    Amauroderma rugosum is a wild medicinal mushroom also known as budak cendawan sawan. Members of the indigenous Malaysian Temuan community wear the fresh stipes as a necklace to prevent epileptic seizure and unremitting crying by babies. In our previous studies, A. rugosum exhibited significant antioxidant and anti-inflammatory activities. The aim of this study was to determine the toxicity (in the event that a stipe is accidentally bitten) and cytotoxicity of this mushroom on Sprague-Dawley rats and selected cell lines. A. rugosum was orally administered to test chemicals according to Organisation for Economic and Co-operation and Development guidelines (TG 425, adopted October 3, 2008). Blood samples were hematologically and biochemically analyzed and multiple tissue sections from each organ were examined using light microscopy. Cytotoxicity of various A. rugosum extracts was also determined against MCF-7 and A-549 cell lines. Our results showed that oral administration of a single dose of mycelial powder (2000 mg/kg) had no adverse effect on the growth rate or hematological and clinical biochemical parameters. Histological studies showed that the treatments did not induce any pathological changes in the organs of the tested animals. All the treated rats survived beyond the 14-day observation period. Methanol and cold and hot water extracts of the freeze-dried mycelial culture of A. rugosum exhibited no or little cytotoxic effect against the MCF-7 and A-549 cell lines.
  11. Recovery of lignin peroxidase from submerged liquid fermentation of Amauroderma rugosum (Blume & T. Nees) Torrend using polyethylene glycol/salt aqueous two-phase system
    Jong WYL, Show PL, Ling TC, Tan YS
    J Biosci Bioeng, 2017 Jul;124(1):91-98.
    PMID: 28319022 DOI: 10.1016/j.jbiosc.2017.02.008
    Amauroderma rugosum is a wild mushroom species widely distributed in tropics and is classified under the class of Basidiomycetes. Basidiomycetes are well-known for their abilities of producing lignocellulolytic enzymes such as lignin peroxidase (LiP), laccase (Lac) and manganese peroxidase (MnP). Different factors such as nutrient sources, incubation period and agitation affect the production of lignocellulolytic enzymes. The A. rugosum produced LiP in the medium supplemented with potato dextrose broth (PDB), 0.5% yeast and 1.0% saw dust at 26.70±3.31 U/mL. However, the LiP activity was increased to 106.32±5.32 U/mL when supplemented with 150 μm of copper (CuSO4). The aqueous two-phase system (ATPS) is a simple, rapid and low cost method for primary extraction and recovery of LiP. A total of 25 systems made from five different molecular weights of polyethylene glycol (PEG)/dipotassium hydrogen phosphate (K2HPO4) were tested. PEG 600 produced the highest top phase purification factor (PFT) of 1.33±0.62 with yield of 72.18±8.50%. The optimization of the ATPS parameters, such as volume ratio VR, pH and crude enzyme loading are the factors controlling the phase partition. Our results showed that significant improvement (PFT of 6.26±2.87 with yield of 87.31±3.14%) of LiP recovery can be achieved by optimized the parameters.
  12. Fulltext 12-(3,4,5-Tri-meth-oxy-phen-yl)-2,3,4,12-tetra-hydro-1H-5-oxa-tetra-phen-1-one: crystal structure and Hirshfeld surface analysis
    Jotani MM, Iniyavan P, Vijayakumar V, Sarveswari S, Tan YS, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Jun 01;72(Pt 6):809-14.
    PMID: 27308048 DOI: 10.1107/S2056989016007775
    In the title compound, C26H24O5, the pyran ring has a flattened-boat con-formation, with the 1,4-related ether O and methine C atoms lying 0.1205 (18) and 0.271 (2) Å, respectively, above the least-squares plane involving the doubly bonded C atoms (r.m.s deviation = 0.0208 Å). An envelope conformation is found for the cyclo-hexene ring, with the flap atom being the middle methyl-ene C atom, lying 0.616 (2) Å out of the plane defined by the remaining atoms (r.m.s. deviation = 0.0173 Å). The fused four-ring system is approximately planar, with the dihedral angle between the least-squares planes through the cyclo-hexene and naphthyl rings being 10.78 (7)°. The tris-ubstituted benzene ring occupies a position almost perpendicular to the pyran ring [dihedral angle = 83.97 (4)°]. The most prominent feature of the packing is the formation of zigzag supra-molecular chains mediated by aryl-C-H⋯O(meth-oxy) inter-actions; chains are connected into a three-dimensional architecture by methyl-ene- and methyl-C-H⋯π inter-actions. The prevalence of C-H⋯O and C-H⋯π inter-actions is confirmed by an analysis of the Hirshfeld surface. A comparison with related structures suggests that the mol-ecular conformation of the title compound is relatively robust with respect to varying substitution patterns at the methine C atom of the pyran ring.
  13. Fulltext Expression and DNA methylation of SERK, BBM, LEC2 and WUS genes in in vitro cultures of Boesenbergia rotunda (L.) Mansf
    Karim R, Tan YS, Singh P, Khalid N, Harikrishna JA
    Physiol Mol Biol Plants, 2018 Sep;24(5):741-751.
    PMID: 30150851 DOI: 10.1007/s12298-018-0566-8
    The process of somatic embryogenesis and plant regeneration involve changes in gene expression and have been associated with changes in DNA methylation. Here, we report the expression and DNA methylation patterns of SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK), BABY BOOM (BBM), LEAFY COTYLEDON 2 (LEC2) and WUSCHEL (WUS) in meristematic block of newly emerged shoots from rhizome, embryogenic and non-embryogenic calli, prolonged cell suspension culture, ex vitro leaf, and in vitro leaf of regenerated plants of Boesenbergia rotunda. Among all seven samples, based on qRT-PCR, the highest level of expression of SERK, BBM and LEC2 was in embryogenic callus, while WUS was most highly expressed in meristematic block tissue followed by embryogenic callus. Relatively lower expression was observed in cell suspension culture and watery callus for SERK, LEC2 and WUS and in in vitro leaf for BBM. For gene specific methylation determined by bisulfite sequencing data, embryogenic callus samples had the lowest levels of DNA methylation at CG, CHG and CHH contexts of SERK, LEC2 and WUS. We observed negative correlation between DNA methylation at the CG and CHG contexts and the expression levels of SERK, BBM, LEC2 and WUS. Based on our results, we suggest that relatively higher expression and lower level of DNA methylation of SERK, BBM, LEC2 and WUS are associated with somatic embryogenesis and plant regeneration in B. rotunda.
  14. Fulltext Outcome after neoadjuvant chemotherapy in Asian breast cancer patients
    Lim LY, Miao H, Lim JS, Lee SC, Bhoo-Pathy N, Yip CH, et al.
    Cancer Med, 2017 Jan;6(1):173-185.
    PMID: 28000426 DOI: 10.1002/cam4.985
    We aim to identify clinicopathologic predictors for response to neoadjuvant chemotherapy and to evaluate the prognostic value of pathologic complete response (pCR) on survival in Asia. This study included 915 breast cancer patients who underwent neoadjuvant chemotherapy at five public hospitals in Singapore and Malaysia. pCR following neoadjuvant chemotherapy was defined as 1) no residual invasive tumor cells in the breast (ypT0/is) and 2) no residual invasive tumor cells in the breast and axillary lymph nodes (ypT0/is ypN0). Association between pCR and clinicopathologic characteristics and treatment were evaluated using chi-square test and multivariable logistic regression. Kaplan-Meier analysis and log-rank test, stratified by other prognostic factors, were conducted to compare overall survival between patients who achieved pCR and patients who did not. Overall, 4.4% of nonmetastatic patients received neoadjuvant chemotherapy. The median age of preoperatively treated patients was 50 years. pCR rates were 18.1% (pCR ypT0/is) and 14.4% (pCR ypT0/is ypN0), respectively. pCR rate was the highest among women who had higher grade, smaller size, estrogen receptor negative, human epidermal growth factor receptor 2-positive disease or receiving taxane-based neoadjuvant chemotherapy. Patients who achieved pCR had better overall survival than those who did not. In subgroup analysis, the survival advantage was only significant among women with estrogen receptor-negative tumors. Patients with poor prognostic profile are more likely to achieve pCR and particularly when receiving taxane-containing chemotherapy. pCR is a significant prognostic factor for overall survival especially in estrogen receptor-negative breast cancers.
  15. The impact of pharmacist interventions, follow-up frequency and default on glycemic control in Diabetes Medication Therapy Adherence Clinic program: a multicenter study in Malaysia
    Lim PC, Tan HH, Mohd Noor NA, Chang CT, Wong TY, Tan EL, et al.
    J Pharm Policy Pract, 2023 Jul 05;16(1):83.
    PMID: 37408067 DOI: 10.1186/s40545-023-00583-8
    BACKGROUND: Pharmacist's involvement in optimizing medication adherence among diabetic patients has been implemented for over a decade. Diabetes Medication Therapy Adherence Clinic (DMTAC) was set up to educate diabetic patients, monitor treatment outcomes, and manage drug-related problems. While evidence shows that pharmacist-led DMTAC was effective in reducing HbA1c, there was limited data regarding the impact of different intervention types and default to follow-up on glycemic control.

    AIM: To assess the impact DMTAC on glycemic control and the difference in glycemic control between hospital and health clinic settings as well as defaulter and non-defaulter. In addition, the impact of pharmacist's interventions, DMTAC follow-up frequencies, and duration of diabetes on glycemic control were also determined.

    METHODS: A retrospective study was conducted among diabetes patients under DMTAC care between January 2019 and June 2020 in five hospitals and 23 primary health clinics. Patients' demographics data, treatment regimens, frequencies of DMTAC visits, defaulter (absent from DMTAC visits) and types of pharmacists' intervention were retrieved from patients' medical records and electronic database. HbA1c was collected at baseline, 4-6 months (post-1), and 8-12 months (post-2).

    RESULTS: We included 956 patients, of which 60% were females with a median age of 58.0 (IQR: 5.0) years. Overall, the HbA1c reduced significantly from baseline (median: 10.2, IQR: 3.0) to post-1 (median: 8.8, IQR: 2.7) and post-2 (median: 8.3, IQR: 2.6%) (p 

  16. Leveraging nitrogen occurrence in approved drugs to identify structural patterns
    Masand VH, Al-Hussain S, Alzahrani AY, El-Sayed NNE, Yeo CI, Tan YS, et al.
    Expert Opin Drug Discov, 2024;19(1):111-124.
    PMID: 37811790 DOI: 10.1080/17460441.2023.2266990
    BACKGROUND: The process of drug development and discovery is costly and slow. Although an understanding of molecular design principles and biochemical processes has progressed, it is essential to minimize synthesis-testing cycles. An effective approach is to analyze key heteroatoms, including oxygen and nitrogen. Herein, we present an analysis focusing on the utilization of nitrogen atoms in approved drugs.

    RESEARCH DESIGN AND METHODS: The present work examines the frequency, distribution, prevalence, and diversity of nitrogen atoms in a dataset comprising 2,049 small molecules approved by different regulatory agencies (FDA and others). Various types of nitrogen atoms, such as sp3-, sp2-, sp-hybridized, planar, ring, and non-ring are included in this investigation.

    RESULTS: The results unveil both previously reported and newly discovered patterns of nitrogen atom distribution around the center of mass in the majority of drug molecules.

    CONCLUSIONS: This study has highlighted intriguing trends in the role of nitrogen atoms in drug design and development. The majority of drugs contain 1-3 nitrogen atoms within 5Å from the center of mass (COM) of a molecule, with a higher preference for the ring and planar nitrogen atoms. The results offer invaluable guidance for the multiparameter optimization process, thus significantly contributing toward the conversion of lead compounds into potential drug candidates.

  17. Fulltext In silico studies, X-ray diffraction analysis and biological investigation of fluorinated pyrrolylated-chalcones in zebrafish epilepsy models
    Mohd Fahmi MSA, Swain P, Ramli AH, Wan Ibrahim WN, Saleh Hodin NA, Abu Bakar N, et al.
    Heliyon, 2023 Feb;9(2):e13685.
    PMID: 36852036 DOI: 10.1016/j.heliyon.2023.e13685
    Epilepsy is the third most common known brain disease worldwide. Several antiepileptic drugs (AEDs) are available to improve seizure control. However, the associated side effects limit their practical use and highlight the ongoing search for safer and effective AEDs. Eighteen newly designed fluorine-containing pyrrolylated chalcones were extensively studied in silico, synthesized, structurally analyzed by X-ray diffraction (XRD), and biologically and toxicologically tested as potential new AEDs in zebrafish epilepsy in vivo models. The results predicted that 3-(3,5-difluorophenyl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (compound 8) had a good drug-like profile with binding affinity to γ-aminobutyric acid receptor type-A (GABAA, -8.0 kcal/mol). This predicted active compound 8 was effective in reducing convulsive behaviour in pentylenetetrazol (PTZ)-induced larvae and hyperactive movements in zc4h2 knockout (KO) zebrafish, experimentally. Moreover, no cardiotoxic effect of compound 8 was observed in zebrafish. Overall, pyrrolylated chalcones could serve as alternative AEDs and warrant further in-depth pharmacological studies to uncover their mechanism of action.
  18. Angiosarcoma - a rare fatal cause of recurrent pericardial effusions
    Ng BH, Tan YS, Pavitratha P, A Hing C, Zainul NH, Lim CH
    Med J Malaysia, 2020 11;75(6):759-761.
    PMID: 33219196
    A 40-year-old man presented to the Hospital Sultanah Bahiyah, Alor Setar, Kedah, with constitutional and respiratory symptoms. Physical examination and echocardiogram demonstrated massive pericardial effusion. Patient required multiple attempts of pericardiocentesis due to recurrent pericardial effusion. Initial workup including pericardial fluids examination and computed tomography imaging did not reveal any apparent cause. Magnetic resonance imaging showed a suspicious mass infiltrating into the right atrium. Autoimmune screening was negative. Patient was subsequently treated as having tuberculous pericarditis. However, his disease progressed rapidly and he eventually passed away due to right atrial rupture. Postmortem revealed a ruptured right atrial tumour leading to massive haemothorax. Histopathological examination confirmed the diagnosis of primary pericardial angiosarcoma.
  19. Fulltext Amino Acid and Secondary Metabolite Production in Embryogenic and Non-Embryogenic Callus of Fingerroot Ginger (Boesenbergia rotunda)
    Ng TL, Karim R, Tan YS, Teh HF, Danial AD, Ho LS, et al.
    PLoS One, 2016;11(6):e0156714.
    PMID: 27258536 DOI: 10.1371/journal.pone.0156714
    Interest in the medicinal properties of secondary metabolites of Boesenbergia rotunda (fingerroot ginger) has led to investigations into tissue culture of this plant. In this study, we profiled its primary and secondary metabolites, as well as hormones of embryogenic and non-embryogenic (dry and watery) callus and shoot base, Ultra Performance Liquid Chromatography-Mass Spectrometry together with histological characterization. Metabolite profiling showed relatively higher levels of glutamine, arginine and lysine in embryogenic callus than in dry and watery calli, while shoot base tissue showed an intermediate level of primary metabolites. For the five secondary metabolites analyzed (ie. panduratin, pinocembrin, pinostrobin, cardamonin and alpinetin), shoot base had the highest concentrations, followed by watery, dry and embryogenic calli. Furthermore, intracellular auxin levels were found to decrease from dry to watery calli, followed by shoot base and finally embryogenic calli. Our morphological observations showed the presence of fibrils on the cell surface of embryogenic callus while diphenylboric acid 2-aminoethylester staining indicated the presence of flavonoids in both dry and embryogenic calli. Periodic acid-Schiff staining showed that shoot base and dry and embryogenic calli contained starch reserves while none were found in watery callus. This study identified several primary metabolites that could be used as markers of embryogenic cells in B. rotunda, while secondary metabolite analysis indicated that biosynthesis pathways of these important metabolites may not be active in callus and embryogenic tissue.
  20. Effect of solvent pre-treatment on the physicochemical, thermal profiles and morphological behavior of Mangifera pajang seed fat
    Norazlina MR, Tan YS, Hasmadi M, Jahurul MHA
    Heliyon, 2021 Sep;7(9):e08073.
    PMID: 34622074 DOI: 10.1016/j.heliyon.2021.e08073
    In this work, the effect of solvent pre-treatment (hexane, petroleum ether and ethanol) on the physicochemical, thermal and morphology behavior of Mangifera pajang seed fat (MPSF) were investigated. Fat extraction was performed using Soxhlet method, and results showed that the yield, physicochemical, and crystalline structures of the MPSF were significantly (p < 0.05) influenced by the extraction solvents. Hexane gave the highest fat yield (7.67 %) with low unsaturation value (52.13 g iodine/g) compared with petroleum ether and ethanol. Hexane MPSF also had low oxidation rate (peroxide value of 1.1 mEq/g). Both non-stabilized and stabilized hexane MPSF showed a single melting endothermic peak at high temperature with onset, maximum peak and offset temperature of 16.23 ˚C-18.21 °C, 28.22 ˚C-31.25 °C and 34.85 ˚C-39.58 °C, respectively. Hexane MPSF crystallized rapidly at high temperature with single maximum peak starting at 16.51 ˚C-16.68 °C and ending at 0.23 ˚C-1.13 °C. In comparison with ethanol extract, hexane MPSF demonstrated a compact crystalline structure with a large densely packed center. Therefore, MPSF obtained from hexane presented better overall quality than those obtained from other extraction solvents. MPSF exhibited similar melting and morphological behavior to mango kernel fat and commercial cocoa butter. These results suggested that hexane was the best solvent for the extraction of MPSF. This fat also has the potential to be applied as a cocoa butter alternative fat or functional fat.
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