Phytochemical and Biological Activity Studies of Cosmos Caudatus and Curcuma Mangga and the Online Characterization of Bioactive Fractions from Melicope ptelefolia

Twelve species of Malay traditional vegetables were screened for antioxidant and nitric oxide (NO) inhibitory activities. Ferric thiocyanate (FTC), thiobarbituric acid (TBA) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) methods were used for the antioxidant activity measurements, and the Griess assay on elicited murine peritoneal macrophages was used to assess NO inhibitory activity of the extracts. Melicope ptelefolia, Cosmos caudatus, and Curcuma mangga were selected for further study, based on the results of their biological activity evaluations. Characterization of the NO inhibitory fractions of the Melicope ptelefolia using on-line high performance liquid chromatography (HPLC)-diode array detector (DAD)-mass spectrometry (MS), identified seven main constituents. The compounds were identified as kokusaginine (1), either kokusagine (2a) or 5- methoxymaculine (2b), 3-prenyl-2,4, 6-trihydroxyacetophenone (3), 3 (4), 3-geranylgeranyl- 2,4,6-trihydroxyaceto-phenone (5), 3-[4-O-(3,7-dimethyl-2, 6-octadienyl)phenyl]-2-propenoic acid (6),and 3- farnesylgeranyl-2,4,6-trihydroxyacetophenone (7). Phytochemical investigation of the methanolic extract of Cosmos caudatus led to the isolation of four known compounds namely, quercetin 3-O-β- arabinofuranoside (17), quercetin 3-O-α-rhamnoside (18), quercetin 3-O-β-glucoside (19), and quercetin (20). All four compounds isolated from C. caudatus showed strong antioxidant activity. The activity was in the order of 20 > 17 > 18 > 19 > α-tocopherol (standard)

Reliability issues and improvement of preliminaries cost related items for civil engineering conventional contracts

Civil engineering is a professional discipline that deals with built environment which involves physical construction of man-made structures such as roads, rails, bridges, drains, water supply, geotechnical systems, and services. It also deals with soft skills such as maintenance, research and investigation, conservation, and planning. In Malaysia, it is a prerogative that civil engineers administer civil engineering contracts. The preliminaries are an integral part of the bill of quantities and difficult to price due to their nature. However, the contractor is expected to price all items fully. The engineer prepares the preliminaries but the risk and liabilities are ultimately transferred to the contractor notwithstanding the reliability of the bill itself. As such, the reliability of preliminaries is of the utmost concern. The research focused on the improvement of the reliability of the preliminaries. The aim is to improve the effectiveness of present preliminaries in Civil Engineering conventional contracts. The objectives are, (1) To investigate the existing cost of item consideration and strategic approaches, (2) To improve the criteria of cost-related item components and expand their potential strategies. This paper considered previous research findings and highlighted the issues and problems related to the fallacy of the subject. Based on the preliminary survey (N=18), it was obvious that the issues concerning the reliability of preliminaries do exist. The research proceeded with a mass survey (N=270) of stratified data sampling involving Malaysian civil engineering contractors belonging to G7 CE21 class, as well as civil engineering consultants and developers. The survey used Likert scales, which ranged from 1 for “Strongly Disagree” to 5 for “Strongly Agree”. The analysis predominantly used SPSS statistics. The results conspicuously exposed the issues and the weaknesses of present practices. The improvement in the criteria of the present practices’ is expected to increase the reliability of preliminaries. As a way forward, the improved criteria provide better clarity, accuracy, and transparency to engineers and contractors as well as other construction players in general. Reliable preliminary items improve price accuracy for the betterment of the construction industry

Effects of Myristica fragrans Houtt. (nutmeg) extract on chemical characteristic of raw beef during frozen storage

The objective of this study was to investigate the effect of nutmeg (Myristica fragrans Houtt.) extract at different concentrations on chemical characteristics of raw beef under frozen storage. Nutmeg extracts at concentrations of 0.25%, 0.65%, 1.25%, 2.50% and 5.00% (g/ml) were used to treat raw beef (2.5 × 2.5 × 1.0 cm; 4 ± 0.5 g) with dilution method. Treated samples were then individually packed in overwrapped trays and stored for 3 weeks at -18 ± 1°C. The effects of the extract on the chemical characteristics such as lipid oxidation, colour, pH, moisture, fat, and protein content of raw beef were evaluated at 0, 4, 7, 10, 14 and 21 days of storage. Lipid oxidation was evaluated based on thiobarbituric acid-reactive substance (TBARS) content. Colour of beef was observed by spectrophotometer in colorimetic parameters CIELabs. Values of pH were measured using pH meter. Moisture, fat and protein content were determined using method by Analysis Association of Official Analytical Chemists (AOAC). The result showed that extract at concentration of 1.25% inhibited TBARS value meaning that extract of 1.25% or more was able to maintain the oxidative stability of beef at -18°C. A 1.25% of extract was also able to maintain the redness (a*) of treated beef compared to untreated during frozen storage. The pH values of all samples beef decreased starting from 10th day of storage. Untreated samples (0.00%) showed the lowest pH values compared to other treated samples at the end day of storage. There was no significant different in term of protein content in all treated or untreated samples. However, fat and moisture content were significantly affected by the concentration of nutmeg extract. Treated beef was able to retain its moisture with only loss of moisture ranging from 0.2% - 2.00% while untreated samples had 5.00% loss of moisture. The fat content of untreated samples (0.00%) showed a reduction of 0.2% of fat content at the end of storage compared to all treated sample with only loss of 0.1% - 0.05%. Overall, nutmeg extract can be used to maintain the chemical characteristics of raw beef during storage for 3 weeks

Integration of screencast video through qr code: an effective learning material for m-learning

This study aimed to evaluate the effectiveness of online screencast video integration through the Quick Response code (QR code) as mobile learning (m-learning). In the flipped classroom, the QR code is distributed to the students to access the screencast video as a means of disseminating lecture notes through their mobile devices. A total of 19 in-service teachers from Technical Colleges, Teacher Training Institute participated in the study. Through this QR code, students can access the learning materials before they come to class. Next, in the classroom, the lecturer will engage students in collaborative learning activities. Thus, in this paper, the researchers discuss about usability testing using a five-point Likert scale, through a questionnaire consisting of the following four constructs: learnability, efficiency, attitude and flexibility. Results from this study showed that the highest mean is efficiency. Thus, we can conclude that through the integration of video screencast by scanning the QR code, can be a potential tool to support the use of m-learning, and also support the blended learning

Effects of curcumin analogue, 2, 6-bis (2, 5-dimethoxybenzylidene) cyclohexanone (BDMC33) on the activities of drug-metabolizing enzymes in cultured Caco-2 cell model

Poor systemic delivery of curcumin outside the gut due to its rapid metabolism has severely limited its application to many chronic diseases. Previously, our research group synthesized curcumin analogues 2, 6-bis (2, 5-dimethoxybenzylidene) cyclohexanone (BDMC33) that has potent anti-inflammatory activities. Therefore, the aim of this study is to evaluate the effects of curcumin analog (BDMC33) on the activities of drug metabolizing enzymes in Caco-2 cells, which was compared with that of curcumin and 3-(2-Fluoro-benzylidene)-5-(2-fluorocyclohexylmethylene)-piperidin-4-one (EF-24). BDMC-33 was synthesized through the appropriate reaction of the aromatic aldehyde with cyclohexanone, under base catalyzed aldol condensation, at the ratio of ketone: aldehyde (1:2). Activity of drug metabolizing enzymes such as NADPH-cytochrome p450 reductase (CPR), UDP-glucuronosyltransferase (UGT), glutathione-S-transferase (GST) and Sulfotransferase (SULT) in Caco-2 cells were evaluated upon exposure to 50µM of BDMC33, curcumin, and EF-24, separately, for 4 hours. The BDMC33, EF-24, and curcumin treatments did not affect the activities of UGT, GST, SULT, and CPR in respect to their controls (29.45, 27.18, 23.64 and 2.08µmol/mg), respectively, at all periods of incubation. Hence, BDMC33 was able to maintain the activities of both phases I and II drug metabolizing enzymes, and therefore it could be a potential lead, anti-inflammatory agents

Effect of different drying treatments and solvent ratios on phytochemical constituents of Ipomoea aquatica and correlation with α-Glucosidase inhibitory activity

Ipomoea aquatica is an aquatic plant that is widely consumed in Southeast Asia as a vegetable. In this study, the influence of various ethanol ratios (0, 20, 50, 80, and 100%) as an extraction solvent and different drying methods including air drying, sun drying, and oven drying on phytochemical constituents of I. aquatica was investigated using a proton nuclear magnetic resonance-based metabolomics approach. The effect on α-glucosidase inhibitory activity and total phenolic content was also examined. Clear discrimination was observed between different ethanol ratios and different drying processes by principal component analysis. The highest α-glucosidase inhibitory activity was observed for absolute ethanol extract from the oven drying method with IC50 value of 204.0 ± 59.0 µg/mL and total phenolic content value of 22.0 ± 0.7 µg gallic acid equivalent/mg extract. Correlation between the α-glucosidase inhibitory activity and the metabolite were analyzed using a partial least square analysis. The metabolites that are responsible for the activity were quercetin derivatives, chlorogenic acid derivatives, sucrose, and fructose. This study highlights the basis for future investigations of I. aquatica as a source of food that has the potential for nutraceutical enhancement and as ingredient in medicinal preparation

Chemical characterization and antioxidant activity of three medicinal Apiaceae species

Centella asiatica (‘Pegaga’ = Malaysia) is well known plant that has been used as one of the ingredients in pharmaceutical and cosmetic industries. Using liquid chromatography with diode array and electrospray ionization/mass spectrometry (LC–DAD–ESI/MS) analysis, chemical profiling of three different Pegaga extracts (C. asiatica, H. bonariensis and H. sibthorpioides) revealed variations in their metabolite profile. Our findings showed that triterpenes of C. asiatica were characterized by the ursane-type triterpenes (madecassoside, asiaticoside, madecassic acid, and asiatic acid), while the two Hydrocotyle species consisted of oleanane-type triterpenes (barrigenol derivatives). Other variations are due to the difference in phenolic and flavonoid constituents. The three Pegaga extracts were also evaluated for their total phenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, and xanthine oxidase inhibition (XOI) activities. The results showed that C. asiatica has the most potent antioxidant activity (TPC = 72.09 mg/100 g DW; DPPH = 72.99 μg/ml; XOI = 87.68 μg/ml) as compared to H. bonariensis (TPC = 28.55 mg/100 g DW; DPPH = 22.43 μg/ml; XOI = 32.23 μg/ml) and H. sibthorpioides (TPC = 56.23 mg/100 g DW; DPPH = 37.86 μg/ml; XOI = 14.73. μg/ml)

In vitro antibacterial activities and composition of Carica papaya cv. Sekaki/Hong Kong peel extracts

Ten solvents were used to extract phytochemicals from the peel of Carica papaya cv. Sekaki/Hong Kong to determine their antibacterial activities. Moderate to clear inhibition on Corynebacterium diphtheriae, Streptococcus pneumoniae, Bacillus subtilis and Clostridium perfringens were obtained from the disk diffusion test out of fourteen pathogens tested. Petroleum ether extract, the most potent extract, showed moderate inhibition towards C. diphtheria and S. pneumoniae at MIC of 5.63 mg/mL and 1.40 mg/mL. Polar solvents gave higher yield, total phenolic and total flavonoid contents than nonpolar solvents. Extract yields were 10.9 to 84.1 mg/g in polar solvents and 3.9 to 20.3 mg/g in non-polar solvents. Twenty eight compounds were identified in petroleum extracts through GC/MS analysis. Among the compounds identified were fatty acids, esters, alkane, tocopherols and sterols. 9,12,15-octadecatrienoic acid was the most abundant compound

Antibacterial and sporicidal activity of Eugenia polyantha Wight against Bacillus cereus and Bacillus subtilis

The spore-forming bacteria, Bacillus spp., have often been associated with the contamination of rice and other starchy products. In this study, the extract of Indonesian bay leaf (Eugenia polyantha) was assessed for its antibacterial and sporicidal activities against vegetative cells and spores of Bacillus cereus ATCC33019 as well as Bacillus subtilis ATCC6633. The Minimum Inhibitory Concentration of E. polyantha extract against vegetative cells of B. cereus and B. subtilis were 0.31 and 0.63 mg/mL, respectively, while both their Minimum Bactericidal Concentration were 2.50 mg/mL. Time kill curves demonstrated that the bactericidal endpoint for B. cereus and B. subtilis was reached at concentration of 2.50 and 5.00 mg/mL, respectively (8× MIC) after 4 h of incubation. E. polyantha extract inactivated more than 3-log (99.99%) of B. cereus and B. subtilis spores at a concentration of 10.00 mg/mL (1.0%) after 1 h of incubation and the spores was completely killed at 25.00 mg/mL (2.5%). The sporicidal activity of E. polyantha extract was not affected by different temperatures treatment and alteration of pH. In conclusion, the potential anti-Bacillus activities of E. polyantha extract might support its use as a natural food preservative

Comparison of Partial Least Squares and Artificial Neural Network for the prediction of antioxidant activity in extract of pegaga (centella) varieties from 1H Nuclear Magnetic Resonance spectroscopy.

Multivariate data analysis of 1H Nuclear Magnetic Resonance spectra was applied for the prediction of antioxidant activity in five different Pegaga (C. asiatica (var 1), C. asiatica (var 2), C. asiatica (var 3) H. bonariensis and H. sibthorpioides) varieties. Linear (Partial Least Square regression) and non linear (Artificial Neural Network) models have been developed and their performances were compared. The performances of the models were tested according to external validation of prediction set. The result showed that the Partial Least Square model provided better generalization than Artificial Neural Network. Despite those, both models are considered reasonably acceptable. Regression coefficient and VIP values of the PLS model revealed that 3,5-O-dicaffeoyl-4-O-malonilquinic acid (irbic acid), 3,5-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid, 5-O-caffeoylquinic acid (chlorogenic acid), quercetin and kaempferol derivatives are the components responsible for the antioxidant activity. In addition, the spectroscopic pattern of the Pegaga varieties, as shown by the PLS score plots was consistent with the corresponding antioxidant activity. Prediction of the antioxidant activity from 1H NMR spectra using this approach is useful in assessing the quality of medicinal herb extracts