Selected physiological and biochemical parameters were monitored at the vegetative and reproductive growth stages in potted Bougainvillea plants treated with five different concentrations of TRIA. Advanced flowering, flower bud number, and blooming rate increased significantly with 0.5 and 1.0 mg/L TRIA treatments. Similarly, photosynthetic rate, pigment content, quantum yield, and stomatal conductance increased significantly with 2.5, 1.0, and 5.0 mg/L TRIA treatments. Higher levels of N, P, and K, as well as increased total soluble solids (TSS) and higher sugar and protein contents, were recorded in treated plants. Furthermore, 46% more flowers, a 1.5-fold increase in bract weight, increased longevity, and 40% less leaf abscission were recorded following 2.5 mg/L TRIA treatment. Phenol and flavonoid contents, sucrose phosphate synthase (SPS), and antioxidant activities were also markedly increased with 2.5 and 1.0 mg/L TRIA treatments. However, ethylene production was significantly lower in the treated plants. Positive correlations were observed between leaf TSS and flowering time and flower number, between leaf sugar content and bract weight, and between net photosynthesis and bract growth and dry matter production. It can be concluded that the foliar spray of TRIA stimulates growth, enhances flowering, and improves the quality of potted Bougainvillea plants.
The chemical production of methyl oleate using chemically synthesized fatty acid alcohols and other toxic chemicals may lead to significant environmental hazards to mankind. Being a highly valuable fatty acid replacement raw material in oleochemical industry, the mass production of methyl oleate via environmentally favorable processes is of concern. In this context, an alternative technique utilizing Candida rugosa lipase (CRL) physically adsorbed on multi-walled carbon nanotubes (MWCNTs) has been suggested. In this study, the acid-functionalized MWCNTs prepared using a mixture of HNO3 and H2SO4 (1:3 v/v) was used as support for immobilizing CRL onto MWCNTs (CRL-MWCNTs) as biocatalysts. Enzymatic esterification was performed and the efficiency of CRL-MWCNTs was evaluated against the free CRL under varying conditions, viz. temperature, molar ratio of acid/alcohol, solvent log P, and enzyme loading. The CRL-MWCNTs resulted in 30-110 % improvement in the production of methyl oleate over the free CRL. The CRL-MWCNTs attained its highest yield (84.17 %) at 50 °C, molar ratio of acid/alcohol of 1:3, 3 mg/mL of enzyme loading, and iso-octane (log P 4.5) as solvent. Consequently, physical adsorption of CRL onto acid-functionalized MWCNTs has improved the activity and stability of CRL and hence provides an environmentally friendly means for the production of methyl oleate.
Lipase-catalyzed production of palm esters was performed via alcoholysis of palm oil and oleyl alcohol in solvent and solvent-free systems using a 2 L stirred tank reactor (STR). Two immobilized lipases were tested and Lipozyme RM IM exhibited superior performance in both reaction systems. Reusability studies of the enzymes in a solvent-free system also demonstrated the high stability of Lipozyme RM IM as shown by its ability to yield more than 70% palm esters with up to 19 cycles of reusing the same enzymes. Modification of the enzyme washing process improved the stability of Lipozyme TL IM in a solvent system as demonstrated by maintaining 65% yield after 5 times of repeated enzyme use. The scale up process for both lipases was conducted in the presence of solvents by using the impeller tip speed approach. Lipozyme RM IM-catalyzed reaction in a 15 L STR produced 85.7% yield and there was a significant drop to 60.7% in the 300 L STR, whereas Lipozyme TL IM had a lower yield (65%) when the reaction volume was increased to 15 L. The low yields could be due to the accumulation of enzymes at the bottom of the vessel. Purification of palm esters via solvent-solvent extraction revealed that more than 90% of oleyl alcohol was extracted after the third extraction cycle at 150 rpm impeller speed with reduced palm esters: ethanol ratio (v/v) from 1:4 to 1:3.
A series of new mesogenic azomethine diols were successfully synthesized by condensation reactions between various chloroalkanols and N,N'-bis(4-hydroxy)-benzylidene-o-toluidine (1). The structures of these compounds were confirmed by CHN, FT-IR, (1)H-NMR, and (13)C-NMR spectrophotometer. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC) and polarizing optical microscope (POM). 4,4'-di(4-Hydroxybutoxy)-N-benzylidine-o-tolidine (2a) does not exhibit liquid crystalline properties. A nematic texture was observed for mesogenic diols 2b, and 2d, whereas the diol 2c exhibits a smectic mesophase. The increase of terminal alkyl chain in these mesogenic diols leads to a decrease in the transition temperature.
Engkabang fat esters were produced via alcoholysis reaction between Engkabang fat and oleyl alcohol, catalyzed by Lipozyme RM IM. The reaction was carried out in a 500 ml Stirred tank reactor using heptane and hexane as solvents. Response surface methodology (RSM) based on a four-factor-five-level Central composite design (CCD) was applied to evaluate the effects of synthesis parameters, namely temperature, substrate molar ratio (oleyl alcohol: Engkabang fat), enzyme amount and impeller speed. The optimum yields of 96.2% and 91.4% were obtained for heptane and hexane at the optimum temperature of 53.9°C, impeller speeds of 309.5 and 309.0 rpm, enzyme amounts of 4.82 and 5.65 g and substrate molar ratios of 2.94 and 3.39:1, respectively. The actual yields obtained compared well with the predicted values of 100.0% and 91.5%, respectively. Meanwhile, the properties of the esters show that they are suitable to be used as ingredient for cosmetic applications.
The kinetics of wax ester synthesis from oleic acid and oleyl alcohol using immobilized lipase from Candida antartica as catalyst was studied with different types of impeller (Rushton turbine and AL-hydrofoil) to create different mixing conditions in 2l stirred tank reactor. The effects of catalyst concentration, reaction temperature, and impeller tip speed on the synthesis were also evaluated. Rushton turbine impeller exhibited highest conversion rate at lower impeller tip speed as compared to AL-hydrofoil impeller. A second-order reversible kinetic model from single progress curve for the prediction of fractional conversion at given reaction time was proposed and the corresponding kinetic parameter values were calculated by non-linear regression method. The results from the simulation using the proposed model showed satisfactory agreement with the experimental data. Activation energy shows a value of 21.77 Kcal/mol. The thermodynamic parameters of the process, enthalpy and entropy, were 21.15 Kcal/mol and 52.07 cal/mol.K, respectively.
Esterification of succinic acid with oleyl alcohol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was investigated in this study. Response surface methodology (RSM) based on a five-level, four-variable central composite design (CCD) was used to model and analyze the reaction. A total of 21 experiments representing different combinations of the four parameters including temperature (35-65°C), time (30-450 min), enzyme amount (20-400 mg), and alcohol:acid molar ratio (1:1-8:1) were generated. A partial cubic equation could accurately model the response surface with a R(2) of 0.9853. The effect and interactions of the variables on the ester synthesis were also studied. Temperature was found to be the most significant parameter that influenced the succinate ester synthesis. At the optimal conditions of 41.1°C, 272.8 min, 20 mg enzyme amount and 7.8:1 alcohol:acid molar ratio, the esterification percentage was 85.0%. The model can present a rapid means for estimating the conversion yield of succinate ester within the selected ranges.
Chromatographic fingerprints of gingers from five different ginger-producing countries (China, India, Malaysia, Thailand and Vietnam) were newly established to discriminate the origin of ginger. The pungent bioactive principles of ginger, gingerols and six other gingerol-related compounds were determined and identified. Their variations in HPLC profiles create the characteristic pattern of each origin by employing similarity analysis, hierarchical cluster analysis (HCA), principal component analysis (PCA) and linear discriminant analysis (LDA). As results, the ginger profiles tended to be grouped and separated on the basis of the geographical closeness of the countries of origin. An effective mathematical model with high predictive ability was obtained and chemical markers for each origin were also identified as the characteristic active compounds to differentiate the ginger origin. The proposed method is useful for quality control of ginger in case of origin labelling and to assess food authenticity issues.
The aim of the present work was to produce low sugar cookies by partial substitution with a
sugar replacer (i.e. maltitol, sorbitol, and isomalt) for sucrose. Four different types of cookies
were prepared. Sucrose was replaced by maltitol, sorbitol, and isomalt at 50% level (based on
relative degree of sweetness of sucrose) to produce CMAL50, CSOR50, and CISO50, respectively. Cookies that contained sucrose represented the control. All the cookies produced were
analysed for chemical properties, physical properties, and sensorial acceptance. The chemical
analysis results indicated that CMAL50, CSOR50, and CISO50 had higher moisture, crude
fibre, and the total carbohydrate content, but with lower ash, crude protein, crude fat, calories,
and total sugar content than the control. CSOR50 showed the lowest total sugar content; thus,
could be denoted as ‘low sugar’ cookies. Cookies containing maltitol and isomalt presented
good physical quality. The hardness value of cookies decreased with 50% substitution of
sorbitol and isomalt for sucrose. CISO50 showed the lowest lightness and yellowness values
than other cookie samples. The sensory evaluation results showed that the cookies incorporated with maltitol and isomalt did not influence the overall acceptability of cookies. In conclusion, the replacement of sucrose with maltitol, sorbitol, and isomalt could reduce sugar and
daily calorie intake. However, sorbitol substitution at 50% level is feasible to produce ‘low
sugar’ cookies, and this cookie could provide benefits to weight and health-conscious
consumers.
The effects of different types of low-sweetness sugar (lactitol, maltodexrin, palatinit, polydextrose,
trehalose) on the physicochemical properties of threadfin bream (Nemipterus spp.) surimi during six months of frozen storage were investigated. The characteristics analyzed were moisture content, pH, water-holding capacity, whiteness, folding test, gel strength, expressible moisture, and texture profile analyses. Generally, the cryoprotective effectiveness decreased as the storage time increased. Polydextrose was able to maintain a water-holding capacity of 77.0%, 98.6% whiteness, a folding test value of 100%, and a gel strength of 53.6% compared with its initial value during six months of frozen storage. Meanwhile, sucrose was able to maintain a water-holding capacity of 80.3%, 98.6% whiteness, a folding test value of 75%, and a gel strength of 56.8%
compared with its initial value. Raw surimi was able to maintain water holding capacity of 62.2%, 98.7% whiteness, a folding test value of 75%, and a gel strength of 36.0% compared with its initial value. It is suggested that, polydextrose as a potential alternative cryoprotectant to replace other low-sweetness sugars.
Spillage of water polluting substances via industrial disaster may cause pollution to our environment. Thus, reversed-flow gas chromatography (RF-GC) technique, which applies flow perturbation gas chromatography, was used to investigate the evaporation and estimate the diffusion coefficients of liquid pollutants. Selected alcohols (99.9% purity) and its mixtures were used as samples. The evaporating liquids (stationary phase) were carried out by carrier gas-nitrogen, 99.9% purity (mobile phase) to the detector. The findings of this work showed the physicochemical measurements may vary depending on the composition of water and alcohol mixtures, temperature of the mixtures, as well as the types of alcohol used. This study implies that there is a variation in the results based on the concentration, types and temperature of the liquids that may contribute in the references for future research in the area of environmental pollution analysis.
Blood alcohol levels from 155 UKM forensic postmortem cases of various causes of death from August 1988 to mid-September 1989 were studied. 59 cases (38%) were related to fatal road traffic accidents. 13 of these 59 cases (22%) showed blood alcohol levels of more than 50 mg/dl. 11 of these 13 cases (84.6%) revealed blood alcohol levels of more than 100 mg/dl after correction. Further analysis showed 53.8% were Indian, 76.9% aged between 20 and 40 years, 84.6% of the accidents occurred between 8.00 p.m. and 4.00 a.m. and all the alcohol related fatal road traffic accident victims studied in this series were males. This study provides helpful information.
Human sweet taste receptor (hSTR) recognizes a wide array of sweeteners, resulting in sweet taste perception. Maltitol and lactitol have been extensively used in place of sucrose due to their capability to prevent dental caries. Herein, several molecular modeling approaches were applied to investigate the structural and energetic properties of these two polyols/hSTR complexes. Triplicate 500 ns molecular dynamics (MD) simulations and molecular mechanics/generalized Born surface area (MM/GBSA)-based free energy calculations revealed that the TAS1R2 monomer is the preferential binding site for maltitol and lactitol rather than the TAS1R3 region. Several polar residues (D142, S144, Y215, D278, E302, R383, and especially N143) were involved in polyols binding through electrostatic attractions and H-bond formations. The molecular complexation process not only induced the stable form of ligands but also stimulated the conformational adaptation of the TAS1R2 monomer to become a close-packed structure through an induced-fit mechanism. Notably, the binding affinity of the maltitol/TAS1R2 complex (ΔGbind of -17.93 ± 1.49 kcal/mol) was significantly higher than that of the lactitol/TAS1R2 system (-8.53 ± 1.78 kcal/mol), in line with the experimental relative sweetness. These findings provide an in-depth understanding of the differences in the sweetness response between maltitol and lactitol, which could be helpful to design novel polyol derivatives with higher sweet taste perception.
Rice bran is bioactive-rich and has proven health benefits for humans. Moreover, its source, the brown rice has antioxidant, hypolipidemic and other functional properties that are increasingly making it a nutritional staple especially in Asian countries. This study investigated the antiplatelet aggregation mechanisms of crude hexane/methanolic rice bran extract, in which policosanol was the targeted bioactive. Platelets play a vital role in pathogenesis of atherosclerosis and cardiovascular diseases, and their increased activities could potentially cause arterial thrombus formation or severe bleeding disorders. Thus, in this study, platelet aggregation and adhesion of platelets to major components of basal lamina were examined in vitro. In addition, cellular protein secretion was quantified as a measurement of platelet activation.
A series of new pyrazoline derivatives (1b-4c) bearing N-acyl arms and nine to twelve carbon long alkoxy side chains was synthesized and characterized on the basis of spectroscopic data and microanalysis. The nature of self-assembly to understand the interplay of alkoxy chain crystallization and various supramolecular interactions was investigated using single crystal X-ray diffraction studies. Interesting self-assembled supramolecular structures of 1b and 4c were observed in the crystal lattice owing to various CH⋯O, H⋯H, CH⋯π, lonepair⋯π and π⋯π interactions. Further, all the synthesized compounds (1b-4c) were screened for their in vitro antifungal and anti-inflammatory activities. Compounds 2b, 3b, 2c and 3c showed significant to moderate antifungal activity against Microsporum canis whereas most of the other compounds were found inactive against all the five tested fungal strains. Good anti-inflammatory activity was observed for compounds 1b with IC50 value 331 μM compared to 273 μM for Indomethacine, a standard reference drug. The bio-activity data demonstrates the relationship between lipophilicity, solubility and bioavailability.
The phase behaviour of a system composed of amino acid-based surfactant (sodium N-lauroylsarcosinate hydrate), 1-decanol and deionised water was investigated for vesicle formation. Changing the molar ratio of the amphiphiles, two important aggregate structures were observed in the aqueous corner of the phase diagram. Two different sizes of microemulsions were found at two amphiphile-water boundaries. A stable single vesicle lobe was found for 1∶2 molar ratios in 92 wt% water with vesicles approximately 100 nm in size and with high zeta potential value. Structural variation arises due to the reduction of electrostatic repulsions among the ionic headgroups of the surfactants and the hydration forces due to adsorbed water onto monolayer's. The balance of these two forces determines the aggregate structures. Analysis was followed by the molecular geometrical structure. These findings may have implications for the development of drug delivery systems for cancer treatments, as well as cosmetic and food formulations.
Medicinal plants containing active natural compounds have been used as an alternative treatment for cancer patients in many parts of the world especially in Asia (Itharat et al. 2004). In this report, we describe the cytotoxic and apoptotic properties of 1'S-1'-acetoxyeugenol acetate (AEA), an analogue of 1'S-1'-acetoxychavicol acetate (ACA), isolated from the Malaysian ethno-medicinal plant Alpinia conchigera Griff (Zingiberaceae) on human breast cancer cells. Data from MTT cell viability assays indicated that AEA induced both time- and dose-dependent cytotoxicity with an IC(50) value of 14.0 μM within 36 h of treatment on MCF-7 cells, but not in HMEC normal control cells. Both annexin V-FITC/PI flow cytometric analysis and DNA fragmentation assays confirmed that AEA induced cell death via apoptosis. AEA was also found to induce cell cycle arrest in MCF-7 cells at the G(0)/G(1) phase with no adverse cell cycle arrest effects on HMEC normal control cells. It was concluded that AEA isolated from the Malaysian tropical ginger represents a potential chemotherapeutic agent against human breast cancer cells with higher cytotoxicity potency than its analogue, ACA.