Air-dried leaves of both Glycosmis citrifolia and Glycosmis elongata collected from Bogor Botanical Garden, Indonesia were individually extracted with chloroform to give dark viscous extracts after solvent removal. Column chromatographic separation of the extract of G. citrifolia yielded 5(6)-glutene-3α-ol, two sets conformers, (E)-dambullin and (Z)-dambullin, and (E)-methyldambullin and (Z)-methyldambullin. Similar treatment of the extract of G. elongata gave skimmianine and arborinine. The structures of the compounds were elucidated based on spectroscopic data and comparison with published reports.
In recent years, there are growing trends in using palm oil as raw materials in radiation curable resins production. In this study, the acrylated palm oil resins i.e. the EPOLA (epoxidized palm oil acrylate) and the POBUA (palm oil based urethane acrylate) were synthesized using two different systems, i.e. the 25 liter pilot scale reactor synthesis system and the 2 liter (L) laboratory scale reactor synthesis system through chemical processes known as acrylation and isocyanation. In this
paper, the property of the acrylated resins which were produced by these two systems were evaluated and compared between each other. Their properties were characterized using the Fourier transform infrared (FTIR) spectrophotometer for functional group identification; the gel permeation chromatography (GPC) for molecular weight (Mw) determination, the Brookfield viscometer for viscosity measurements, the acid values (AV) and the oxirane oxygen contents (OOC) analysis. As a result, the production process for both the 2 L and 25 L reactor system were found to be time consuming and the main advantages for the 25 L reactor was its higher productivity as compared with the 2 L reactor system with the same synthesis process parameters i.e. the temperatures and the experimental methods. Besides that, the 25 L reactor synthesis
process was found to be safe, easy to control and served unpolluted process to the environments. The final products, the acrylated palm oil resins were formulated into ultraviolet (UV) curable compounds before subjecting them under UVirradiation. As a result, the UV-curable palm oil resins showed potential uses as pressure sensitive adhesives, printing inks including overprint varnishes (OPV) and coatings.
Previously, researchers had initiated investigation to find an alternative drug that can treat diabetes mellitus without dragging patients into more complicated health problems. After many studies, they found a new and high potential plant-based drug named stevia that is able to reduce diabetic patients’ blood glucose. This study aimed to determine the effect of stevia on blood glucose of healthy subjects. The study was carried out by comparing the glycemic response between sucrose and stevia (500 and 1000 mg) among 32 subjects aged between 18 and 23 years old. Subjects were required to fast 8 to 10 h prior to each test which was done on different days. Finger prick test were done on 0, 30, 60, 90 and 120 min to construct a blood sugar response curve for 2 h period. There is a significant difference between the glycemic response of sucrose and stevia 500 mg. Sucrose significantly increased the post prandial blood glucose while stevia 500 mg reduced blood glucose after 30 min of consumption. Sucrose also produced higher glycemic response at min-30 when compared with stevia 1000 mg. There is no significant difference between the glycemic response of stevia of different dose, 500 and 1000 mg. No dose-dependent effect was observed in this study. In conclusion, stevia does not raise blood glucose significantly when consumed in short period. Stevia is effective to be used by healthy people to maintain blood glucose even when consumed in short length of time.
Artikel ini bertujuan mengkaji keberkesanan program SHIELDS daripada perspektif pelajar dan urusetia yang telah turut terlibat. Program SHIELDS adalah satu bentuk program campbased yang diperkenalkan hasil kerjasama antara Kementerian Pendidikan dan Pihak Agensi Anti Dadah Kebangsaan (AADK). Nama SHEILDS ini adalah akronim yang bermaksud Sayangi Hidup, Elak Derita Selamanya. Sehubungan itu, program ini bertujuan meningkatkan kesedaran dan mengupayakan ketahanan diri murid (lingkungan umur 13 hingga 18 tahun) yang dikenalpasti berisiko dalam penyalahgunaan dadah. Kajian kuantitatif ini melibatkan dua fasa iaitu fasa pertama adalah mengedarkan soal selidik sebelum dan selepas program SHIELDS dijalankan. Manakala, fasa kedua pula adalah sesi follow up selepas 3 bulan terhadap 50 pelajar yang telah terlibat dengan program SHIELDS terlebih dahulu. Hasil kajian menunjukkan secara keseluruhan perspektif pelajar seramai 559 orang yang terlibat dengan program SHIELDS ini adalah baik dengan min=4.48. Kesimpulannya, dapatan ini menunjukkan bahawa program SHIELDS ini sewajarnya diteruskan dengan beberapa penambahbaikan untuk kelangsungan program dan kebaikan semua pihak yang terlibat.
The phenomenon of adolescents involved with drug abuse is a worrying and very serious issue. The influence of drug-related partners would have a bad effect on other teens, especially teenagers who are at risk. Therefore, this study aims to identify the extent of the level of knowledge of the drug, especially in relation to the differences of attitudes in terms of physical effects, hindering behaviors, involvement in drug-related activities and information on how to distribute, attitude towards self and future, and risk factors amongst students who did take drugs as compared to who never took it. This is a cross-sectional study involving 559 teenagers at risk, aged between 13-18 years’ old who are involved in SHIELDS Programme, camp based programme that was introduced by Agensi Anti dadah Kebangsaan (AADK) in collabaration with the Ministy of Education. Findings showed that there is a significant difference between students who have taken drugs and those who have never used it for dimension of hindering behavior, involvement in drug-related activities and information on how to distribute, risk factors of the involvement of immediate family members with drugs and negative consequences of drug intake. Because the involvement with drugs negatively impacts adolescents, thus, the prevention of this deviance behavior must be implemented as best as possible to ensure that the future of these adolescents is upheld, to prevent them from falling into another crime.
Yeasts with GRAS (Generally Regarded as Safe) status are commonly used as hosts for heterologous protein production. Yeasts are suitable expression hosts as they have been extensively characterised genetically. The objective of this project was to isolate yeasts from Malaysian food sources and subsequently to develop these as alternative hosts for heterologous protein production. Yeasts were isolated from Malaysian traditional fermented food namely ‘tapai’, ‘tuak’ and ‘ragi’. A total of 23 isolates were obtained and subjected to molecular identification by amplification and sequencing of the universally conserved ribosomal internal transcribed spacer (ITS), 26S rDNA and 18S rDNA sequences. We identified three species of yeasts, Saccharomyces cerevisiae, Hanseniaspora guilliermondii and Pichia anomala, which have a long tradition of usage in food production and have no adverse effects on humans. To test the feasibility of the yeasts as heterologous expression hosts, we have constructed an integrative vector, p1926Zeo containing the yeast 26S rDNA and Zeocin® resistance cassette. The p1926Zeo vector was linearised and transformed into both P. anomala and H. guilliermondii isolates via electroporation. Both hosts were successfully transformed at a relatively high efficiency. The transformants obtained had a growth profile similar to the respective wild type, indicating that integration of the plasmids into the host chromosome did not affect growth. These transformants were stable as they exhibited resistance to Zeocin even after 20 generations. Thus, both P. anomala and H. guilliermondii isolates exhibited the potential to be further developed as alternative heterologous protein expression hosts.
This article describes the preparation of titanium dioxide (TiO2) hollow fiber membrane using phase inversion and sintering technique. In this study, nano-sized TiO2 powders with different particle sizes were used to prepare ceramic hollow fiber membranes. In a series of preparation steps, a dispersant was dissolved in organic solvent before the addition of ceramic powders. These steps were followed by the addition of polymer binder. The membrane precursor was obtained by extruding the ceramic suspension into a coagulation bath, which enabled the precipitation of the precursor of ceramic hollow fiber membrane. The dried precursor was later sintered at temperatures ranging from 1200 to 1300oC to obtain TiO2 hollow fiber membrane. Scanning electron microscopy (SEM) was used to study the morphology of TiO2 hollow fiber membrane. The SEM images show the membrane can be shaped into asymmetric structure and symmetric structure based on the ceramic suspension compositions. The highest mechanical strength obtained was 223 MPa when the membrane prepared using 20 wt. % ceramic loading of single nano-sized powder and sintered at 1300oC. TiO2 hollow fiber membrane prepared using similar ceramic loading showed high permeation rate of inert gas. High pure water fluxes were obtained when permeability tests was carried out using TiO2 hollow fiber membrane, prepared using mixture of nano-sized particles, even though its cross-section have a sponge-like structure.
Kajian ini bertujuan menterjemahkan soalselidik Skala Konsep Kendiri Multidimensi (SKKM) edisi bahasa Inggeris ke dalam bahasa Malaysia, mendapatkan kesahan kandungan dan nilai kebolehpercayaan. SKKM dibina oleh Bracken (1992) bertujuan mengukur konsep kendiri berdasarkan Model Konsep Kendiri Multidimensi (MKKM). SKKM mempunyai 150 item (74 item positif dan 76 item negatif) yang mengukur enam sub skala konsep kendiri iaitu konsep kendiri sosial, kemampuan, perasaan, keluarga, fizikal dan akademik. Proses penterjemahan SKKM ke dalam bahasa Malaysia menggunakan kaedah back translation yang dicadangkan oleh Brislin, Lonner dan Thondike (1973). Item-item dalam SKKM diubahsuai mengikut nilai dan budaya masyarakat tempatan dan dinilai terjemahannya oleh tiga panel bahasa Melayu dan tiga panel bahasa Inggeris. Bagi analisis kesahan muka seramai lapan pelajar sekolah menengah dan tiga pakar bahasa Melayu terlibat dalam membaiki bahasa, struktur ayat dan kefahaman istilah-istilah dalam SKKM. Seterusnya, SKKM dinilai oleh tujuh panel pakar bagi menilai kesahan kandungannya. Seterusnya analisis kepercayaan dijalankan terhadap 214 pelajar di dua buah sekolah menegah di negeri Selangor, Malaysia. Dapatan kajian mendapati nilai kesahan kandungan oleh panel pakar memperoleh nilai koefisien yang tinggi iaitu = 0.822 dengan nilai minimum dan maksimum juga melebihi .60. Nilai koefisien terendah ialah bagi sub skala konsep kendiri keluarga iaitu .668 dan nilai tertinggi ialah bagi sub skala konsep kendiri sosial iaitu .964. Analisis kebolehpercayaan SKKM juga memuaskan dengan nilai keseluruhan ialah .757. Huraian berdasarkan subskala ialah Sosial α = .7.93, Kemampuan α = .770, Perasaan α = .744, Keluarga α = .680, Fizikal α = .791 dan Akademik α = .762. Bagi analisis nilai kebolehpercayaan berdasarkan item-item mendapati nilai kebolehpercayaan tertinggi ialah soalan nombor 103 subskala keluarga iaitu .902 dan nilai terendah ialah item soalan nombor 49 subskala kemampuan iaitu .762. Justeru kajian ini berjaya menterjemahkan SKKM yang mempunyai nilai kesahan dan kebolehpercayaan yang tinggi dan boleh diaplikasikan dalam kalangan remaja di Malaysia.
This study examined the genetic characteristics of twenty-six microsatellite primers developed from three cyprinid fishes (Cyprinus carpio Linnaeus, Barbus barbus Linnaeus and Barbonymus gonionotus Bleeker) in two indigenous mahseer. The Tor douronensis Valenciennes were randomly collected from two locations in Sarawak (N=52), while Tor tambroides Bleeker were obtained from Peninsular Malaysia (N=56). A total of ten and twelve primers were successfully amplified producing four and five polymorphic loci in T. douronensis and T. tambroides, respectively. The number of alleles per locus ranging from 2 to 5 in T. douronensis and 2 to 7 in T. tambroides. A significant deviation from Hardy-Weinberg equilibrium (HWE) was observed at three loci (Barb37, Barb59 and Barb62) in one or more populations in T. tambroides while two loci (Barb37 and Barb62) were deviated in T. douronensis population of Batang Ai. Population structure analysis showed low level of inter-population genetic differentiation in both mahseer. Overall, the identified microsatellite loci should be useful in analysing T. douronensis and T. tambroides natural populations.
Kitin merupakan polisakarida struktur yang dapat dicurai oleh enzim kitinolisis kepada pelbagai terbitan yang boleh digunakan dalam bidang perubatan, pertanian dan rawatan air. Pengenalpastian dan pencirian gen-gen Trichoderma virens UKM1 mengekod enzim terlibat dalam pencuraian kitin krustasea telah dilakukan melalui penjanaan penanda jujukan terekspres (ESTs) dan analisis pengekspresan gen menggunakan mikroatur DNA. Sebanyak tiga perpustakaan cDNA T. virens UKM1 yang masing-masing diaruh oleh kitin, glukosamina dan kitosan telah dibina. Sejumlah 1536 klon cDNA telah dijujuk dan sebanyak 1033 ESTs berkualiti telah dijana. Seterusnya, perbezaan pengekspresan gen apabila pertumbuhan kulat diaruh dengan kehadiran kitin krustasea dan tanpa kitin pada hari ketiga dan kelima telah ditentukan. Sebanyak 1824 klon cDNA telah dititik ke atas slaid kaca dan dihibrid bersama dengan cDNA terlabel Cy3 atau Cy5 yang disintesis daripada mRNA yang dipencil daripada kulat yang ditumbuhkan dalam medium mengandungi kitin krustasea atau glukosa (kawalan). Sebanyak 91 dan 61 gen, masing-masing bagi hari ketiga dan kelima didapati terekspres melebihi dua gandaan apabila kulat menggunakan kitin krustasea sebagai sumber karbon. Beberapa gen mengekod kitinase seperti ech1 dan cht3 (endokitinase), nag1 (eksokitinase) dan nagB (glukosamina 6-P-deaminase) didapati terekspres dengan tinggi pada kedua-dua hari. Selain daripada itu, gen mengekod protein hidrofobin, protease serina dan beberapa protein hipotetik juga terekspres dengan tinggi dengan kehadiran kitin krustasea. Protein-protein ini dijangka memainkan peranan penting dalam membantu pencuraian kitin krustasea.
Solanum ferox L. is a plant species which belongs to the Solanaceae family and the genus Solanum. The Solanum genus was found to exhibit anticariogenic activity and was traditionally used to treat oral diseases. However, there is no scientific study done specifically for Solanum ferox L. Hence the aim of the study is to determine the anticariogenic properties of flesh and leaf of ethanolic extract of Solanum ferox L. Alkaloids, flavonoids and tannins were detected in the leaf ethanolic extract via preliminary phytochemical screening. The presence of these phytochemicals may contribute to the anticariogenic activity. Treatment with different concentrations of flesh and leaf of ethanolic extract were used against Streptococcus pyogenes and Staphylococcus aureus via the method of agar well diffusion to indicate zones of inhibition. The antibiofilm activity of the flesh and leaf ethanolic extracts was tested. The flesh and leaf ethanolic extracts possess antimicrobial activity dose-dependently and positive antibiofilm activity against respective pathogens. The flesh ethanolic extract has stronger anticariogenic activity compared to leaf ethanolic extract against respective pathogens. Streptococcus pyogenes exhibited higher susceptibility as compared to Staphylococcus aureus. In conclusion, it has been shown that the ethanolic extract of Solanum ferox L. exhibit anticariogenic properties against Streptococus pyogenes and Staphylococcus aureus.
Psychosocial hazards present in workplaces are being actively investigated by researchers from multiple domains. More research and resources are required to investigate the debilitating consequences of these hazards in the developing and underdeveloped countries where this issue remains one of grave concern. This study aims at investigating the psychometric properties of Malaysian version of Copenhagen Psychosocial Questionnaire for reliability and validity purpose. The Malaysian version of COPSOQ is a multidimensional questionnaire; it comprises of 7 major formative constructs and 28 variables with an additional inclusion of two variables which are organizational loyalty and physiological health biomarkers (blood pressure and body mass index) that explicate a reflective construct which has 93 items all catering to assess psychosocial determinants present in workplace environments. Each formative second-order construct is further categorized into different reflective first-order constructs. The focus of this study was only on first-order reflective constructs. Probability sampling was used for data collection from 300 respondents working in industries with a response rate of 100%; structural equation modeling technique was applied for data analysis. All psychometric analysis performed on reflective constructs gave reliable results which demonstrate the validity of Bahasa Melayu (BM-COPSOQ) and its comprehensiveness of including relevant dimensions particularly in context to Asian region. The BM-COPSOQ will fill up the knowledge gap and provide a bridge between researchers, work professionals and practitioners, and many other workplaces for the best understanding of psychosocial work environment.
A normal health status is highly depends on body weight. Many health problems may occur or impose risk for
extremely obese individuals. Etiopathology of obesity includes interaction of several factors inclusive of
genetic and non-genetic factors such as lifestyle changes. This study aimed to launch Malaysian Obesity
DNA Bank and determine the prevalence of obesity along with anthropometric measurements of the subjects.
The cross-sectional study was conducted on total of 340 subjects (obese = 95, overweight = 122 and normal =
123), aged 19-60 years, in Terengganu. The BMI and well appropriate anthropometric measurements (waist
circumference, hip circumference, waist to hip ratio, fat percentage and ASindex) were determined through
standard protocols and formulae. The mean difference of anthropometrics was determined by independent ttest. Data was analysed using SPSS ver.16.0.0. The BMI was determined for all subjects and it was found that
out of 340 subjects, a total of 95 (27.9%) subjects were obese , followed by a total of 122 (35.8%) subjects
were overweight and normal individuals were 123 (36.1%). The mean of the BMI, WHR, Fat% and ASindex,
in Malay obese were 32.83, 0.88, 33.5 and 13.21 respectively, while in normal healthy individuals were 22.1,
0.78, 24.2 and 20.1 respectively. The difference of mean of BMI, WHR, Fat% and ASindex was calculated to
be 10.73, 0.1, 9.3 and 6.89 respectively. To the best of our knowledge, this is the first report in Malaysia,
reporting that this is very first Obesity DNA Bank in South East Asia region and prevalence of obesity in
Terengganu, Malaysia to be 27.9%. In addition, it indicates a significant mean difference for anthropometric
measurements among obese and normal individuals. For Asindex calculations suggest that the prevalence of
genocide obesity is greater 89.9% of android obesity in Malay obese attributes
.
The aim of this study is to compare the effectiveness of cold water immersion (CWI) and progressive muscle relaxation (PMR) on DOMS markers among young athletes. A total of 30 young athletes with mean age of 18.57 ± .504 years old, weight 61.92 ± 7.96 kg and height 170.67 ±7.57 cm volunteered to participate in this study. Participants were required to perform 20 reps x 5 sets drop jump (DJ) to induce muscle damage. They were randomly assigned into three groups: CWI (n = 10), PMR (n = 10) and control group (n = 10). Immediately following damage-inducing exercise protocol, CWI group were required to submerge lower body until iliac crest level in 15°C±1°C of cold water for 16 minutes; whereas control group applied the same position without immersed in cold water for 16 minutes. Perceived muscle soreness, range of motion (ROM) thigh circumference and the 20 meter sprint have been used as DOMS markers in this study. Markers were measured pre-exercise, post-exercise, post-intervention, and after 24 hours, 48 hours, 72 hours and 96 hours. The results of mixed ANOVA revealed a significant interaction (p < 0.05) in 20-meter sprint between groups and measurements at 24 hours and post-interventions, respectively. Conversely, no significant interactions were found in perceived muscle soreness, ROM and thigh circumference (p > 0.05). In conclusion, a single bout of CWI and PMR are not beneficial to elicit positive effects on DOMS markers used in this study.
Centella asiatica is one of the traditional herbs consumed by many communities due to its wide range of applications such as treating Parkinsonism, promoting memory enhancement, and preventing oxidative stress. This study was conducted to investigate the neuroprotective potential of aqueous C. asiatica extract (CAE) against neurodegeneration induced by chronic stress. Administration of CAE at three different dosages (200 mg/kg/day, 400 mg/ kg/day and 800 mg/kg/day) was conducted for a period of 21 days along with exposure to chronic stress using restrainer and forced swimming regimes. The administration of CAE significantly improved the thickness of dentate gyrus and reduced the amount of neuronal cell death at dentate gyrus and CA3 (p
Islam merupakan satu agama yang menitikberatkan kesihatan manusia termasuklah sistem pencernaan manusia. Najis
(tinja) manusia yang dibincangkan dalam kajian ini merupakan hasil buangan manusia yang menjadi salah satu kaedah
untuk melihat sudut kesihatan manusia. Objektif penyelidikan ini ialah untuk mengkaji fizikokimia dan ciri-ciri najis
serta kegunaannya daripada perspektif sains dan sudut pandangan Islam terutamanya mengenai diet yang diamalkan
oleh Rasulullah SAW. Kajian ini dijalankan dengan menggunakan ulasan literatur secara deskriptif. Kajian mendapati
bahawa sistem pencernaan merupakan satu sistem yang rumit. Tinja terdiri daripada 75% air dan 25% bahan pepejal
serta ciri-ciri tinja seperti bentuk, warna dan bau memberi kesan kepada kesihatan manusia. Daripada sudut Islam
warna, bau dan rasa tinja merupakan perkara asas yang dititikberatkan semasa proses pembersihan najis terutamanya
bagi memulakan sesuatu ibadah. Selain itu, diet, senaman, umur dan jantina merupakan faktor-faktor yang membezakan
jenis tinja bagi setiap individu. Malah, kajian ini juga merungkai beberapa alternatif yang kini diguna pakai bagi
mengurus najis-najis manusia dalam menjamin kesihatan dan pemeliharaan alam sekitar. Kajian ini kemudiannya
mengupas diet makanan-makanan sunnah yang terdapat di dalam Al-Quran dan hadis yang terbukti kaya dengan serat
dan sihat untuk manusia terutamanya bagi sistem pencernaan manusia. Oleh itu, najis (tinja) manusia daripada sudut
sains mampu menggambarkan kesihatan seseorang dan amalan diet makanan-makanan sunnah sangat baik dalam
memelihara sistem pencernaan manusia.
In this study, graphene-on-silicon process technology was developed to fabricate a power rectifier Schottky diode for efficiency improvement in high operating temperature. Trench-MOS-Barrier-Schottky (TMBS) diode structure was used to enhance the device performance. The main objective of this research was to study the effect of reduced graphene oxide (RGO) deposited on silicon surface for Schottky barrier formation and heat transfer in Schottky junction. The study showed RGO deposited on silicon as a heat spreader could help to reduce the effect of heat generated in the Schottky junction that leads to a leakage current reduction and efficiency improvement in the device. With comparison to the conventional metal silicide (titanium silicide and cobalt silicide), the leakage reduced by two-orders of magnitude when tested under high operating temperature (>100°C). TMBS rectifier diode that uses graphene-based heat spreader could produce highly reliable product able to withstand high temperature operating condition.
The stability of the limestone cliff at Gunung Kandu, Gopeng, Perak, Malaysia was assessed based on the Slope Mass
Rating (SMR) system on 53 cross sections of the Gunung Kandu hill slopes. The slopes of Gunung Kandu were identified
as class I (very good) to IV (poor). The kinematic analysis showed that 12 out of 53 hill slopes of Gunung Kandu were
identified as having potential wedge, planar and toppling failures. The assessment showed that the stability of the western
flanks can be classified as stable to unstable with the probability of failure from 0.2 to 0.6. The stability of the eastern and
southern flanks range from very stable to partially stable with the probability of failure from 0.0 to 0.4. While the stability
of northern flanks are from very stable to stable with the probability of failure of 0.0 - 0.2. This systematic approach
offers a practical method especially for large area of rock slope stability assessment and the results from probability of
failure values will help engineers to design adequate mitigation measures.
The use of photoplethysmography (PPG) as one of cardiovascular disease (CVD) marker has got more attention due to
its simplicity, noninvasive and portable characteristics. Two new markers had been developed from PPG namely PPG
fitness index (PPGF) and vascular risk prediction index (VPRI). The aim of the present study was to compare PPGF level
between young women with and without CVD risk factors, to investigate the relationship between PPGF with other CVD
markers and to assess the sensitivity of VRPI in classifying young women that have CVD risk factors. A total of 148 young
women aged 20-40 years old with and without CVD risk factors were involved in this study. CVD risk factors comprised of
abdominal obesity, hypertension, dyslipidemia, smoking and family history of premature CVD. Subjects were categorized
into healthy or having CVD risk factor. Measurements taken were anthropometric data, blood pressure, lipid profile,
pulse wave velocity (PWV), augmentation index (AIx), high sensitivity C-Reactive Protein (hs-CRP), PPGF and VRPI. SPSS
version 20 was used for data analysis with p<0.05 as significant value. The mean subjects’ age was 29.97±5.27 years
old. There was no difference in PPGF level between groups (p>0.05). PPGF was independently determined by PWV (β=-
0.31, p<0.001) and height (β=0.16, p=0.04). VRPI had 77.9% sensitivity in identifying subjects with CVD risk factor. In
conclusion, PPGF correlates with PWV and has potential to be an indicator of aortic stiffness while VRPI is sensitive to
classify those with CVD risk factor.
Microbial production of natural products using metabolic engineering and synthetic biology approaches often involves
the assembly of multiple gene fragments including regulatory elements, especially when using eukaryotes as hosts.
Traditional cloning strategy using restriction enzyme digestion and ligation are laborious and inflexible owing to the
high number of sequential cloning steps, limited cutting sites and generation of undesired ‘scar’ sequences. In this study,
a homology-based isothermal DNA assembly method was carried out for one-step simultaneous assembly of multiple DNA
fragments to engineer plant phenylpropanoid biosynthesis in Saccharomyces cerevisiae. Rapid construction of yeast
plasmid harboring dual gene expression cassettes was achieved via isothermal assembly of four DNA fragments designed
with 20 bp overlapping sequences. The rate-limiting enzyme of phenylpropanoid pathway, cinnamate 4-hydroxylase
encoded by C4H gene from Polygonum minus was cloned in tandem with yeast promoter and terminator elements of S.
cerevisiae for efficient construction of phenylpropanoid biosynthetic pathway in recombinant yeast. The assembled pAGCAT (C4H-ADH1t-TEF1p) shuttle plasmid and transformation of S. cerevisiae with the plant C4H gene were confirmed
via PCR analysis. Based on these findings, the yeast shuttle plasmid harboring P. minus phenylpropanoid biosynthesis
gene was efficiently constructed to be the starting platform for the production of plant natural products in geneticallyengineered S. cerevisiae.