Three compounds were isolated and characterized from the roots of Goniothalamus woodii. Based on their spectroscopic data, the compounds were identified as goniothalamin, 5-acetoxygoniothalamin and goniotriol.
Tiga sebatian telah dipisahkan dan dicamkan daripada akar Goniothalamus woodii. Berdasarkan dari data spektroskopi, sebatian telah dikenalpasti sebagai goniotalamin, 5-asetoksigoniotalamin dan goniotriol.
A new species from the Goniothalamus genus, G. tomentosus, was investigated. Two alkaloids, aristololactam BII 1 and ouregidione 2 together with a stigmasterol isolated from the stem bark and roots were identified using spectroscopic techniques.
Spesies baru daripada genus Gonitothalamus, G. tomemtosus telah dikaji. Dua sebatian alkaloid aristololaktam BII 1 dan ouregidion 2 serta stigmasterol yang dipencilkan daripada kulit batang dan akar telah ditentukan dengan menggunakan teknik spektroskopi.
Minyak pati Goniothalamus ridleyi daripada sampel segar dan kering bahagian kulit batang, kayu, buah, akar dan
daun telah diekstrak menggunakan hidro penyulingan. Minyak pati tersebut telah dianalisis menggunakan kromatografi
gas (KG) kapilari dan kromatografi gas-spektrometer jisim (KG-SJ). Komposisi sebatian kimia dalam minyak pati telah
dikenal pasti secara perbandingan data spektrum jisim sampel dengan spektrum jisim yang ada dalam rujukan Wiley,
perbandingan pengiraan indeks penahanan dengan nilai kepustakaan dan ko-kromatografi bagi sesetengah sebatian
dengan sebatian autentik pada turus kapilari DB-5. Sebanyak 50 sebatian telah dikenal pasti dan mewakili 89.5% minyak
pati kulit batang segar G. ridleyi. Minyak pati daripada kulit batang segar kaya dengan sebatian linalool (15.2%) dan
sitronellal (10.9%). Sejumlah 47 sebatian telah dikenal pasti dan mewakili 90.1% jumlah minyak pati kayu segar yang
menunjukkan kehadiran sebatian utama β-eudesmol (27.1%) dan γ-eudesmol (20.8%). Sementara itu, minyak pati
daripada bahagian buah menunjukkan kehadiran 49 sebatian serta mewakili 89.8% jumlah minyak pati. Sebatian utama
dalam minyak pati buah adalah β-kubebena (20.7%) dan elemol (20.2%). Sebatian utama dalam sampel segar adalah
sama dengan sebatian utama dalam sampel kering, kecuali bahagian sampel kering didapati kaya dengan sebatiansebatian
seperti β-karyofilena, limonena, β-selinena, viridifloral, α-kopaena dan cyperena.
Phytochemical studies were conducted on the stem bark, stem, root and fruit of Goniothalamus ridleyi (Annonaceae)
collected at Post Brooke, Gua Musang, Kelantan, Malaysia. Extraction using organic solvent followed by extensive
purification using standard procedure afforded an epoxystyryllactone, 5-acetoxyisogoniothalamin oxide (1) from the
stem bark and fruit; a styryllactone, 5-acetoxygoniothalamin (2) and a styrylpyrone, dehydrogoniothalamin (3) from
the stem and root; a styryllactone, 5-hydroxygoniothalamin (4) from the root and styrylpyrone as well as goniothalamin
(5) from the fruit. These compounds were characterized using spectroscopic techniques.
This study was conducted to investigate pesticide residues in paddy crops derived from two different types of cultivation, namely the cultural plot managed by the Malaysian Agriculture Research and Development Institute (MARDI) and the second from the farmers’ rice fields which did not follow schedules suggested by MARDI. Sample collection was carried out at post harvest. To determine the concentration of organochlorine pesticides, a gas chromatograph equipped with an electron capture detector (GC-ECD) was used. The range of pesticide residues in the leaf samples was from N/D to 579.60 ppb, in stem samples from N/D to 368.93 ppb and in the rice grain from N/D to 22.37 ppb. Some of the rice samples had levels that exceeded the standard MRL (as stipulated by WHO).
A qualitative analysis of the individual compounds in Litsea fulva (locally known as ‘Medang’) essential oils was performed by comprehensive two-dimensional gas chromatography (GC × GC) coupled with time-of-flight mass spectrometer (TOF/MS) for the identification of the resolved peaks. Litsea fulva essential oil was found to contain 98 identifiable peaks with 32 compounds were identified with good matches. These compounds identified included 30 hydrocarbons, 22 alcohols, five acids, 16 ketones, five aldehydes, 12 esters, six ethers and two other compounds. The L. fulva leaf oil contained alcohols and ethers, with 34.09% and 24.38%, respectively. The major components of these oils were cis-Z-α-bisabolene epoxide (9.51%), trans-Z-α-bisabolene epoxide (8.36%), C13H20O2 (7.39%), longipinocarvone (5.68%), τ-Cadinol (4.24%), C15H24O (4.98%) and α-cadinol (3.95%). The study also showed that the comprehensive two-dimensional gas chromatography (GC × GC) is a better and more powerful separation tool in GC and an identification tool for analyzing complex volatile oils compared with the one-dimensional GC.
The chemical compositions of the leaf and bark oils of Xylopia caudata were examined by co-chromatography with authentic samples on a polar capillary column (PEG 20M) and a non polar capillary column (SE-30), GC/MS and further comparison with Kovats Retention Index. The essential oils were mainly made up of monoterpenoids. The major components in both oils were β-pinene, α-pinene, limonene and a-terpineol which collectively represented 90% and 69% of the leaf and bark oils respectively.
Kandungan kimia minyak pati daun dan kulit kayu Xylopia caudata telah dikaji secara ko-kromatografi dengan sampel tulen di atas turus rerambut polar (PEG 20M) dan turus rerambut kurang polar (SE-30), KG/SJ dan perbandingan dengan Indeks Penahanan Kovats. Sebahagian besar minyak pati tersebut terdiri daripada sebatian monoterpenoid. Komponen utama yang terdapat dalam kedua-dua minyak pati tersebut adalah β-pinena, α-pinena, limonena dan a-terpineol yang mewakili 90% dan 69% daripada minyak pati daun dan kulit kayu masing-masing.
Marine fungus Fusarium proliferatum derived from marine sponge collected along Pulau Tinggi, Malaysia was cultivated on Potato Dextrose Broth and incubated for 7 days at 30oC. The liquid cultures were then extracted using ethyl acetate. The crude extract was investigated for its anti-microbial activity and was passed through Sephadex column and the fractions were collected. Reverse phase HPLC was used to monitor the component of crude extract. HPLC guided purification of crude extract resulted in the isolation of linoleic acid, 4-hydroxy phenethyl alcohol, 2,5-furandimethanol and adenosine. Their structures were elucidated by spectroscopic methods.
The objective of this study was to develop a method for the determination of diuron (3-(3,4-dichlorophenyl)-1,1-dimethyl urea) residue in crude palm oil (CPO) and crude palm kernel oil (CPKO) matrices. The method involves the extraction of the herbicide from the oil matrix using low temperature precipitation and solid phase extraction techniques, detected by high performance liquid chromatography-ultra violet (HPLC-UV). The HPLC separation was carried out on an Ascentis
TMRP-Amide column and elution with acetonitrile (solvent A) and water-methanol (2:1, v/v) (solvent B) as a suitable solvent system, at ratio of 4:6 (v/v). The optimum volume of acetonitrile for the extraction of diuron was 30 mL and 4 mL was obtained as the optimum volume of the solvent for elution analyte through the SPE cartridge. A linear correlation was obtained for the concentration of diuron from 0.05–1.0 µg mL-1 with a correlation coefficient of 0.99. The recovery of diuron from CPO was 83.2–101.4% with a relative standard deviation of 1.4–9.9% and 79.4–87.9% with relative standard deviation of 0.9–5.6% for CPKO. The method detection limit and limit of quantification obtained were 0.018 µg g-1 and 0.058 µg g-1, respectively. The method was used to determine diuron residues in palm oil from different refineries situated at different locations throughout Malaysia.
Artificial neural network (ANN) was used in this study to determine water turbidity by using back propagation algorithm. Three wavelengths which represent reflectance intensity for eight standard samples were used as training input. The finding from the study shows that the trained network with number of epochs of 250,000 and learning rate of 0.001 gave the lowest sum of squared error (SSE) of 0.04. ANN was able to predict the turbidity of water based on the pattern recognition of the reflectance spectrum. The architecture of optimized ANN used in this study was 3:25:1. The average prediction error was 0.02.
[Jaringan neural tiruan (ANN) dengan lagoritma perambatan balik (BP) telah digunakan dalam kajian ini untuk menentukan kekeruhan air. Tiga panjang gelombang yang mewakili serapan bagi lapan sampel telah dipilih sebagai imput latihan. Hasil kajian menunjukkan bagi jaringan terlatih dengan bilangan ulangan latihan 250,000 dan kadar pembelajaran 0.001 telah memberikan nilai SSE yang terendah iaitu 0.04. Dalam kajian ini jaringan ANN didapati boleh menentu dan meramalkan nilai kekeruhan sample air berdasarkan corak serapan pantulan. Arkitektur yang sesuai bagi kajian ini adalah 3:25:1. Purata ralat ramalan adalah 0.02].
The lichen collection from Bukit Larut, Taiping, Malaysia in 1999 included Bulbothrix isidiza, Chrysothrix xanthina, Cladonia adspersa, C. verticillata, Coccocarpia palmicola, Heterodermia flabellata, H. japonica, H. obscurata, Hypotrachyna imbricatula, Leptogium azureum, Parmelinella wallichiana, Parmotrema tinctorum, P. clavuliferum, P. reticulatum, Pertusaria sp., Physma byrsaeum, Usnea baileyi and Usnea rubrotincta. Secondary metabolites could not be detected in three lichens, Coccocarpia palmicola, Leptogium azureum and Physma byrsaeum by HPLC and TLC analysis. The other 15 lichen species showed the presence of ten classes of compounds, depsides (10 compounds), depsidones (16), quinones (5), xanthones (2), naphthopyrones (1), pulvinic acid derivatives (1), diphenylethers (1), dibenzofurans (1), aliphatic acids (4) and terpenoids (3).
The phytochemical investigation on the fruit peel of Goniothalamus scortechinii (Selayar Raja Ubat) obtained from Gunung Stong, Kelantan has resulted in the isolation of five compounds namely pinocembrine, altholactone, goniofufurone, goniotriol and goniopypyrone. Their structures were determined by extensive ultra violet (UV), infrared (IR), nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrum (GCMS) analysis.
An investigation of the effect of discharge of domestic sewage to rivers at Kajang (Jeluh and Langat River) and coastal waters at Negeri Sembilan (Port Dickson and Blue Lagoon) was carried out. The parameters studied focused on the characteristics of sewage such as organic content (biochemiÂcal oxygen demand, BOD and nutrients (dissolved phosphate, (PO4) and nitrate (NO)). The discharge of domestic sewage from oxidation ponds near Kajang has resulted in high levels of BOD and PO4 in river water, i.e. 1.9-5.1 and 0.15-2.03 mg/L respectively. The increase in BOD is correlated (r =0.77) with the decrease in the level of dissolved oxygen (DO) in the river water. In general. the effects of domestic sewage discharge on water quality is more obvious in the Jeluh and Langat rivers at Kajang when compared to the effect on marine water.