Penyaringan metabolisme hati dan kajian mekanisme agen anti-malaria artemisinin dan dihidroartemisinin

This project is a collaboration between the author and another lecturer from the Pharmaceutical Chemistry discipline, PPS Farmasi, Assoc Prof Dr Chen Kit Lam, to develop more information on the anti-malaria agent, artemisinin and its synthetic deriavtives, dihydroartemisnin. The plant Artemisia annua has been successfully cultured in the test-tube by Dr Chris Teoh group from USM and information on the chemistry and pharmacology of these substance are being actively investigate by many workers, locally and internationally

Development, validation, and application of HPLC method for quantification of antihyperuricemic compounds from Lippia nodiflora in rat plasma

AbstractAn HPLC method for simultaneous determination of arenarioside (1 ), verbascoside (2), 6-hydroxyluteolin (3), 6-hydroxyluteolin-7-O-glycoside (4), and nodifloretin (5) from Lippia nodiflora in rat plasma was developed and validated. The optimal chromatographic separation was achieved with a gradient mobile phase comprising 0.1% aqueous acetic acid and acetonitrile. The limit of detection was 78.1 ng/mL for 3 and 39.1 ng/mL for the other compounds (signal-to-noise ratio=3), whereas the limit of quantification was 312.5 ng/mL for 3 and 156.3 ng/mL for the other compounds (signal-to-noise ratio=12). The recovery values of compounds 1–5 ranged from 89.37–100.92%. Their accuracy values were between 96.48 and 105.81%, while their corresponding precision values were in the range of 0.75–9.06% for both intraday and inter-day analysis. The method was then applied in the first pharmacokinetic study of 1–5. Following intravenous administration, 1–5 were eliminated slowly from the body with a mean clearance value of 0.11, 0.13, 0.30, 0.09, and 0.23 L/kg h, respectively. Meanwhile, their peak plasma concentration upon oral administration was 8.97, 1.07, 1.06, 0.65, and 0.38 µg/mL, respectively. Compound 3 (5.97%) exhibited the highest absolute oral bioavailability value, followed by 1 (5.22%), 4 (3.13%), 2 (2.10%), and 5 (0.93%)

A Flexible Fuzzy Regression Method for Addressing Nonlinear Uncertainty on Aesthetic Quality Assessments

Development of new products or services requires knowledge and understanding of aesthetic qualities that correlate to perceptual pleasure. As it is not practical to develop a survey to assess aesthetic quality for all objective features of a new product or service, it is necessary to develop a model to predict aesthetic qualities. In this paper, a fuzzy regression method is proposed to predict aesthetic quality from a given set of objective features and to account for uncertainty in human assessment. The proposed method overcomes the shortcoming of statistical regression, which can predict only quality magnitudes but cannot predict quality uncertainty. The proposed method also attempts to improve traditional fuzzy regressions, which simulate a single characteristic with which the estimated uncertainty can only increase with the increasing magnitudes of objective features. The proposed fuzzy regression method uses genetic programming to develop nonlinear structures of the models, and model coefficients are determined by optimizing the fuzzy criteria. Hence, the developed model can be used to fit the nonlinearities of sample magnitudes and uncertainties. The effectiveness and the performance of the proposed method are evaluated by the case study of perceptual images, which are involved with different sampling natures and with different amounts of samples. This case study attempts to address different characteristics of human assessments. The outcomes demonstrate that more robust models can be developed by the proposed fuzzy regression method compared with the recently developed fuzzy regression methods, when the model characteristics and fuzzy criteria are taken into account

A stepwise based fuzzy regression procedure for developing customer preference models in new product development

Fuzzy regression methods have commonly been used to develop consumer preferences models which correlate the engineering characteristics with consumer preferences regarding a new product; the consumer preference models provide a platform whereby product developers can decide the engineering characteristics in order to satisfy consumer preferences prior to developing the products. Recent research shows that these fuzzy regression methods are commonly used to model customer preferences. However, these approaches have a common limitation in that they do not investigate the appropriate polynomial structure which includes significant regressors with only significant engineering characteristics; also, they cannot generate interaction or high-order regressors in the models. The inclusion of insignificant regressors is not an effective approach when developing the models. Exclusion of significant regressors may affect the generalization capability of the consumer preference models. In this paper, a novel fuzzy modelling method is proposed, namely fuzzy stepwise regression (F-SR), in order to develop a customer preference model which is structured with an appropriate polynomial which includes only significant regressors.Based on the appropriate polynomial structure, the fuzzy coefficients are determined using the fuzzy least square regression. The developed fuzzy regression model attempts to obtain a better generalization capability using a smaller number of regressors. The effectiveness of the F-SR is evaluated based on two design problems, namely a tea maker design and a solder paste dispenser design. Results show that better generalization capabilities can be obtained compared with the fuzzy regression methods commonly-used for new product development. Also, smaller-scale consumer preference models with fewer engineering characteristics can be obtained. Hence, a simpler and more effective product development platform can be provided

Quality of life of caregivers with relatives suffering from mental illness in Hong Kong: roles of caregiver characteristics, caregiving burdens, and satisfaction with psychiatric services

<p>Abstract</p> <p>Background</p> <p>The study attempted to explore the quality of life (QoL) of Chinese caregivers with mentally ill relatives. It also aimed to examine the differential roles of caregiving burdens, caregiver characteristics, and satisfaction with psychiatric services in caregivers' QoL.</p> <p>Methods</p> <p>276 caregivers with relatives attending community psychiatric facilities in Hong Kong were invited to fill out a questionnaire. One sample t-tests were conducted to compare the results of this study with that of other Chinese populations in Hong Kong, Taiwan, and mainland China. A hierarchical regression analysis was performed to examine the relative influence of different factors on caregivers' QoL.</p> <p>Results</p> <p>Our sample of caregivers had significantly lower QoL scores than other Chinese populations. Results also suggest that Chinese caregivers who had chronic illness, younger in age, a lower education level, experienced more difficulties in handling negative symptoms, and were more dissatisfied with mental health services had poorer quality of life. Indeed, caregiver characteristics displayed a much stronger association with caregivers' QoL than did caregiving burdens and satisfaction with psychiatric services.</p> <p>Conclusions</p> <p>This study supports the strong association of caregiver characteristics and the QoL of caregivers and establishes the nature of the relationship between satisfaction with mental health services and caregiver QoL. Implications for future research and practice are discussed.</p

(E)-6-Bromo-3-{2-[2-(2-meth­oxy­benzyl­idene)hydrazin­yl]-1,3-thia­zol-4-yl}-2H-chromen-2-one

In the title compound, C20H14BrN3O3S, the mol­ecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thia­zole ring are approximately planar [maximum deviations = 0.029 (3) and 0.007 (3) Å, respectively]. The chromene ring system is inclined at angles of 7.37 (12) and 13.90 (13)° with respect to the thia­zole and benzene rings, respectively, while the thia­zole ring makes a dihedral angle of 12.58 (15)° with the benzene ring. In the crystal, mol­ecules are connected by N—H⋯O hydrogen bonds, forming C(8) supra­molecular chains along the c axis

(E)-6-Bromo-3-{2-[2-(2-chloro­benzyl­idene)hydrazin­yl]thia­zol-5-yl}-2H-chromen-2-one dimethyl sulfoxide monosolvate

In the title compound C19H11N3O2SClBr·C2H6OS, the mol­ecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thia­zole ring are approximately planar, with maximum deviations of 0.027 (2) and 0.003 (1) Å, respectively. The central thia­zole ring makes dihedral angles of 21.82 (9) and 5.88 (7)° with the chloro-substituted phenyl ring and the chromene ring, respectively. In the crystal, mol­ecules are connected via N—H⋯O, N—H⋯S and C—H⋯O hydrogen bonds, forming supra­molecular chains along the c axis. An intra­molecular C—H⋯O hydrogen bond occurs. π–π inter­actions are observed between the thia­zole and phenyl rings [centroid–centroid distance = 3.6293 (10) Å]. A short Br⋯Cl contact of 3.37 (6) Å also occurs

(E)-3-(2-{2-[1-(3-Hy­droxy­phen­yl)ethyl­idene]hydrazin­yl}-1,3-thia­zol-4-yl)-2H-chromen-2-one

In the title compound, C20H15N3O3S, the thia­zole ring is approximately planar, with a maximum deviation of 0.003 (1) Å, and makes dihedral angles of 7.44 (6) and 1.88 (6)° with the hy­droxy-substituted phenyl ring and the pyran ring, respectively. The hydroxyl group is disordered over two sets of sites, with an occupancy ratio of 0.567 (3):0.433 (3). In the crystal, the major disorder component mol­ecules are connected via bifurcated (three-centre) O—H⋯O and C—H⋯O hydrogen bonds, generating R 1 2(6) motifs and resulting in supra­molecular chains along the a axis. In the minor occupancy component, however, mol­ecules are connected via C—H⋯O hydrogen bonds, forming supra­molecular chains along the b axis. Furthermore, the crystal structure is stabilized by π–π inter­actions between the thia­zole rings [centroid–centroid distance = 3.5476 (7) Å]

Multi-targeting aurones with monoamine oxidase and amyloid-beta inhibitory activities: structure-activity relationship and translating multi-potency to neuroprotection

Previously, a series of aurones bearing amine and carbamate functionalities was synthesized and evaluated for their cholinesterase inhibitory activity and drug-like attributes. In the present study, these aurones were evaluated for their multi-targeting properties in two Alzheimer’s disease (AD)-related activities namely, monoamine oxidase (MAO) and amyloid-beta (Aβ) inhibition. Evaluation of the aurones for MAO inhibitory activity disclosed several potent selective inhibitors of MAO-B, particularly those with 6-methoxyl group attached at ring A. Of the different amine moieties attached as side chains, pyrrolidine-bearing aurones were prominent as represented by 2-2, the most potent inhibitor. Evaluation on the Aβ aggregation inhibition identified 4-3 as the best inhibitor with a percentage inhibition comparable to that of a known Aβ inhibitor curcumin. Examination on the neuroprotective ability of the more drug-like aurone 4-3 in two Caenorhabditis elegans neurodegeneration models showed 4-3 to protect the nematodes against both Aβ- and 6-hydroxydopamine-induced toxicities. These new activities further support 4-3 as a promising lead to develop the aurones as potential multipotent agents for neurodegenerative diseases