The accurate determination of reducing ends of malto-oligosaccharides is essential for calculating the enzyme activities of starch debranching enzymes. The suitability of the 3,5-Dinitrosalicylic acid (DNS) method, the Dygert method, and the Bicinchoninic acid (BCA) method for accurate determination of reducing ends from malto-oligosaccharides of different chain lengths is compared. The results showed that BCA assay was much more accurate than the other assays. The results for the BCA assay showed that different malto-oligosaccharides gave observed (measured) values that were significantly similar to the expected (predetermined) values. In contrast, the DNS and Dygert assays underestimated the amount of reducing sugar present for glucose. Furthermore, both DNS and Dygert methods showed increasing degree of overestimation of the amount of reducing sugar present with the increasing length of the malto-oligosaccharide sugar chains. The BCA assay can suitably quantify reducing sugars even in mixtures of oligosaccharides with different chain lengths. Thus, enzyme activities can be measured without bias towards higher values for enzymes that preferentially cleave the longer chain lengths.
Latest progress in the liquid crystal (LC) field related to azo molecules incorporated into natural product- based moieties for the improvement of LC texture and mesomeric phases has received great interest among researchers. A LC containing natural product-based moieties i.e. menthol, kojic acid, cholesterol and chalcone with stable azo and azobenzene scaffolds with specific optical tunability, has been widely used in photo-active materials such as Liquid Crystal Display (LCD), LC films, smart windows and other devices. This review discusses the influence of azobenzene, a renowned photo-responsive and stable LC scaffold, in mesogenic phases due to photo-isomerization and optical switching. The incorporation of mesomeric phases of natural product moieties to azo molecules has improved the properties of LC, i.e, from the nematic phase to the smectic phase with proper magnetic field alignment. Natural product-based LC can be useful in numerous applications, especially practical electronic or optic devices such as optical image storage, display devices, solar cells, optical switching.
Chemical modification of medicines from natural product-based molecules has become of interest in recent years. In this study, a series of halogenated azo derivatives 1a-d were synthesised via coupling reaction, followed by Steglich esterification with aspirin (a natural product derivative) to form azo derivatives 2a-d. While, halogenated azo-aspirin 3a-d were synthesised via direct coupling reaction of aspirin and diazonium salt. Bacteriostatic activity was demonstrated against E. coli and S. aureus via turbidimetric kinetic method. Compound 3a-d showed excellent antibacterial activities against E. coli (MIC 75-94 ppm) and S. aureus (MIC 64-89 ppm) compared to ampicillin (MIC 93 and 124 ppm respectively), followed by 1a-d and 2a-d. The presence of reactive groups of -OH, N=N, C=O and halogens significantly contribute excellent interaction towards E. coli and S. aureus. Molecular dockings analysis of 3a against MIaC protein showed binding free energy of -7.2 kcal/mol (E. coli) and -6.6 kcal/mol (S. aureus).
Agro-waste from the bark of Metroxylon sagu (sago) was studied as a low cost and effective oil sorbent in dry and aqueous environments. Sorption study was conducted using untreated sago bark (SB) and esterified sago bark (ESB) in used engine oil. Characterization study showed that esterification has successfully improved the hydrophobicity, buoyancy, surface roughness and oil sorption capacity of ESB. Sorption study revealed that water uptake of SB is higher (30 min static: 2.46 g/g, dynamic: 2.67 g/g) compared with ESB (30 min static: 0.18 g/g, dynamic: 0.14 g/g). ESB, however, showed higher oil sorption capacity in aqueous environment (30 min static: 2.30 g/g, dynamic: 2.14) compared with SB (30 min static: 0 g/g, dynamic: 0 g/g). ESB has shown great poTENTial as effective oil sorbent in aqueous environment due to its high oil sorption capacity, low water uptake and high buoyancy.
A series of (E)-1-(4-alkyloxyphenyl)-3-(hydroxyphenyl)-prop-2-en-1-one have been successfully synthesised via Claisen-Schmidt condensation. The synthesised chalcone derivatives consisted of hydroxyl groups at either ortho, meta or para position and differed in the length of the alkyl groups, C (n) H(2) (n) (+1,) where n = 6, 10, 12 and 14. The structures of all compounds were defined by elemental analysis, IR, (1)H- and (13)C-NMR. The antimicrobial studies were carried out against wild-type Escherichia coli American Type Culture Collection 8739 to evaluate the effect of the hydroxyl and the alkyl groups of the synthesised chalcones. All the synthesised compounds have shown significant antimicrobial activities. The optimum inhibition was dependent on the position of the hydroxyl group as well as the length of the alkyl chains.
Paraquat poisoning is commonly associated with suicide or homicide in Malaysia. In a case involving advanced body decomposition, pathological analysis regarding the cause of death may become difficult or almost impossible. Insects serve as common alternative matrix for poison detection in forensic analysis. Paraquat detection via secondary bioaccumulation in fly larvae tissue has never been reported. In this study, tissues from blowfly larvae collected from a rabbit carcass with paraquat poisoning were analyzed for secondary bioaccumulation. Larvae samples were collected and analyzed using liquid-liquid extraction. The detection was performed via reduction of quaternary ammonium presence in paraquat and analyzed using gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring mode (SIM mode). GC-MS showed the elution of reduced paraquat was at retention time 12.8 min. Blowfly larvae tissue has proven useful as a secondary detector in paraquat-related deaths.
Porous Carbon Nanoparticles (PCNs) with well-developed microporosity were obtained from bio-waste oil palm leaves (OPL) using single step pyrolysis in nitrogen atmosphere at 500-600 °C in tube-furnace without any catalysis support. The key approach was using silica (SiO2) bodies of OPL as a template in the synthesis of microporous carbon nanoparticles with very small particle sizes of 35-85 nm and pore sizes between 1.9-2 nm.
Biodiesel from palm oil mill sludge (POMS) was prepared in the presence of novel silica-based heterogeneous catalysts derived from Imperata cylindrica sp. Imperatacid and Imperatabase are two types of heterogeneous catalysts derived from Imperata cylindrica sp and characterized using scanning electron microscopy, Energy Dispersive X-ray, Brunauer-Emmett-Teller surface area and pore size measurement. Imperatacid has particle size of 43.1-83.9 µm while Imperatabase in the range of 89-193 µm. Imperatacid was conveniently applied in esterification step to afford > 90 wt% oil in 1:3 (oil/methanol) and 10 wt% catalyst, followed by transesterification with 1 wt% Imperatabase and 1:1 (oil/methanol) for 1 h at 65°C to afford 80% biodiesel with higher percentage of methyl palmitate (48.97%) and methyl oleate (34.14%) compare to conventional homogeneous catalyst. Reusability of the catalyst up to three times afforded biodiesel ranging from 78-80% w/w. The biodiesel was demonstrated onto alternative diesel engine (Megatech(®)-Mark III) and showed proportional increased of torque (ɽ) to biodiesel loading.
The asymmetric unit of the title compound, C22H18N4O2S2, contains two mol-ecules. In one of them, the dihedral angles between the central benzene ring and the phenyl rings are 16.97 (8) and 20.97 (8)°, while the phenyl rings make a dihedral angle of 37.87 (8)°. In the other mol-ecule, the corresponding values are 34.92 (7), 53.90 (7) and 60.68 (8)°, respectively. In each mol-ecule, two intra-molecular N-H⋯O hydrogen bonds generate S(6) rings and a short C-H⋯S contact also occurs. In the crystal, N-H⋯S, N-H⋯O, C-H⋯O and C-H⋯S inter-actions link the mol-ecules into a three-dimensional network.
In the title compound, C(29)H(40)O(3), the enone moiety adopts an s-cis conformation. The dihedral angle between the benzene rings is 4.33 (5)° The least-squares mean line through the tetra-decyl side chain forms a dihedral angle of 83.99 (7)° with the normal to the attached benzene ring. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds involving the keto and the hy-droxy O atoms form ribbons along [-41-1]. The crystal structure also features C-H⋯π inter-actions.
In the title compound, C(21)H(24)O(3), the enone moiety adopts an s-cis conformation and the dihedral angle between the benzene rings is 12.89 (6)°. The hex-yloxy tail adopts an extended conformation. In the crystal, inversion dimers are linked by pairs of O-H⋯O hydrogen bonds and pairs of C-H⋯O inter-actions, forming two R(2) (2)(7) and one R(2) (2)(10) loops. The dimers are then arranged into sheets lying parallel to (201) and weak C-H⋯π inter-actions consolidate the packing.
In the title compound, C(25)H(32)O(3), the enone group adopts an s-cis conformation. The alk-oxy chain is in an all-trans conformation. The dihedral angle between the benzene rings is 7.86 (5)°. In the crystal, mol-ecules are connected by pairs of O-H⋯O hydrogen bonds, forming inversion dimers and giving R(2) (2)(10) rings. Within these dimers, weak C-H⋯O hydrogen bonds form two R(2) (2)(7) rings. In the crystal, the approximately planar mol-ecules [largest deviation for an atom being 0.4737 (12) Å for the terminal C atom of the alk-oxy chain] are arranged in sheets parallel to (20-1). Weak C-H⋯π inter-actions are also observed.
Metroxylon sagu Rottb. or locally known as sago palm is a tropical starch crop grown for starch production in commercial plantations in Malaysia, especially in Sarawak, East Malaysia. This plant species accumulate the highest amount of edible starch compared to other starch-producing crops. However, the non-trunking phenomenon has been observed to be one of the major issues restricting the yield of sago palm starch. In this study, proteomics approach was utilised to discover differences between trunking and non-trunking proteomes in sago palm leaf tissues. Total protein from 16 years old trunking and non-trunking sago palm leaves from deep peat area were extracted with PEG fractionation extraction method and subjected to two-dimensional gel electrophoresis (2D PAGE). Differential protein spots were subjected to MALDI-ToF/ToF MS/MS. Proteomic analysis has identified 34 differentially expressed proteins between trunking and non-trunking sago samples. From these protein spots, all 19 proteins representing different enzymes and proteins have significantly increased in abundance in non-trunking sago plant when subjected to mass spectrometry. The identified proteins mostly function in metabolic pathways including photosynthesis, tricarboxylic acid cycle, glycolysis, carbon utilization and oxidative stress. The current study indicated that the several proteins identified through differentially expressed proteome contributed to physical differences in trunking and non-trunking sago palm.
Sago bark (SB) and empty fruit bunch (EFB) are available abundantly as agricultural waste in Sarawak. This study was conducted to investigate the physicochemical characteristics of SB and EFB as composting materials and used as a plant growth medium. The SB and EFB composts were prepared in a separate container by mixing chicken manure as compost accelerator and wood chips as a bulking agent in dry weight equivalent ratio (1:1:1). The maturity and stability of compost in 60-day composting periods were evaluated via physicochemical characterization of the composts in terms of pH, elemental content, total ash content, moisture content and nutrient analyses. The effect of the compost usage as growth medium was assessed towards water spinach and green mustard via seed germination and pot study. After 2 months, the colour of both composts was dark brown with an earthy smell. The acidic pH of the initial composting stage has changed into alkaline pH after 60 days of composting. Total NPK present in the SB and EFB composts were 0.96% and 1.21%, respectively. The germination index (GI) for the studied vegetables was above 100%, while the pot study showed that vegetables in compost media has higher growth compared to the control, after 14 days. SB and EFB are renewable waste which can be used as an excellent compost and able to improve the quality of the soil.
Chemical modification of active scaffolds from natural products has gained interest in pharmaceutical industries. Nevertheless, the metabolites extraction is time-consuming while the lead is frequently mismatched with the receptor. Here, the diazo coupling approach was introduced to generate a series of vanillin derivatives featuring halogenated azo dyes (1a-h). The vanillin derivatives showed effective inhibition of S. aureus (7-9 mm) and E. coli (7-8 mm) compared to the parent vanillin, while 1b had the highest inhibition zone (9 mm) against S. aureus comparable to the reference ampicillin. The presence of N = N, C = O, -OH, -OCH3 and halogens established strategic binding interactions with the receptor. The potential vanillin-azo as an antimicrobial drug was supported by in silico docking with penicillin-binding proteins and DFT (using Gaussian 09) with binding affinity -7.5 kcal/mol and energy gap (Egap) 3.77 eV, respectively. This study represents a significant advancement in drug discovery for effective antibiotics with excellent properties.
This research provides a comprehensive analysis of groundwater pollution in the Lower Anayari Catchment (LAC) through δ2H and δ18O isotopic analysis, along with positive matrix factorization (PMF) and PCS-MLR receptor models. Forty groundwater samples were collected from hand-dug wells and equipped boreholes across the LAC. Flame photometry for Na+ and K+, complexometric titration for Ca2+, ion chromatography for Cl-, F-, NO3-, SO42-, and PO43-, and atomic absorption spectrometry for Mg2+, Fe, Pb, Cd, As, and Ni were analytical techniques/instruments employed. In regard to cations, Na+ has the highest average concentration of 63.0 mg/L, while Mg2+ has the lowest at 2.58 mg/L. Concerning the anions and nutrients, Cl- has the highest mean concentration of 18.7 mg/L, and Fl- has the lowest at 0.50 mg/L. Metalloids were detected in trace amount with Fe displaying the highest mean concentration of 0.077 mg/L whereas Cd and As recorded lowest (0.001 mg/L). The average values for groundwater δ18O and δ2H were - 3.64‰ and - 20.7‰, respectively; the average values for rainwater isotopic composition were - 3.41‰ for δ18O and - 17.4‰ for δ2H. It is believed that natural geological features, particularly biotite granitoid and volcanic flow/subvolcanic rocks from the Birimian Supergroup, significantly influence groundwater mineralisation. Additionally, the impact of anthropogenic activities on water quality, with urban development and agricultural practices, may be attributed to increasing levels of certain contaminants such as Fe, Ni, NO3-, and PO43-. This research contributes to the broader field of hydrological study and provides practical implications for managing and conserving water resources in similar contexts. The innovative combination of isotopic and statistical analyses sets a new standard for future studies in groundwater quality assessment, emphasising the need for comprehensive approaches that consider both geological characteristics and human impacts for sustainable water resource management.
In searching for drugs from natural product scaffolds has gained interest among researchers. In this study, a series of twelve halogenated thiourea (ATX 1-12)via chemical modification of aspirin (a natural product derivative) and evaluated for cytotoxic activity against nasopharyngeal carcinoma (NPC) cell lines, HK-1 via MTS-based colorimetric assay. The cytotoxicity studies demonstrated that halogens at meta position of ATX showed promising activity against HK-1 cells (IC50 value ≤15 µM) in comparison to cisplatin, a positive cytotoxic drug (IC50 value =8.9 ± 1.9 µM). ATX 11, bearing iodine at meta position, showed robust cytotoxicity against HK-1 cells with an IC50 value of 4.7 ± 0.7 µM. Molecular docking interactions between ATX 11 and cyclooxygenase-2 demonstrated a robust binding affinity value of -8.1 kcal/mol as compared to aspirin's binding affinity value of -6.4 kcal/mol. The findings represent a promising lead molecule from natural product with excellent cytotoxic activity against NPC cell lines.