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The Rutaceae family has been used in traditional medicine practices to treat various ailments such as snake bites, fever, cough and diarrhoea. Clausena excavata, Micromelum minutum and Melicope latifolia are plants of the Rutaceae family grown locally in Malaysia. To date, there are limited studies on the activity of their extracts and compounds on antimicrobial activity against oral pathogenic bacteria, antioxidant capacity especially cellular antioxidant activity as well as cytotoxicity properties. Therefore, this study aimed to investigate the phytochemical constituents, antimicrobial, antioxidant and cytotoxicity properties of C. excavata, M. minutum and M. latifolia. A total of 24 compounds including one new conjugated sesquiterpene were isolated from C. excavata, M. minutum and M. latifolia using different chromatographic techniques. Structural elucidation was achieved by means of spectroscopic and spectrometric analysis. Phytochemical investigation on stem bark of C. excavata yielded four coumarins (dentatin (166), nordentatin (54), clausenidin (64) and xanthoxyletin (66)), three alkaloids (heptazoline (51), clausine H (167) and heptaphylline (67)), together with clausenarin (168). Atranorin (170), a polyketide and lichexanthone (171), a xanthone were also first isolated from the Clausena species. Flavonoids namely araneosol (173), 5-hydroxyauranetin (172) and 5,7-dihydroxy-3,8,4’-trimethoxyflavone (174) together with stigmasterol (169) were isolated from the leaves of M. minutum. Meanwhile, M. latifolia leaves afforded one new conjugated sesquiterpene, trivially named as amelicarin (176) together with nine known compounds consist of sterol derivatives (β-sitosterol (175), β-sitostenone (178), stigmast-4-ene-6β-ol-3-one (179), stigmast-4-ene-3,6-dione (177)), four flavonoid glycosides (quercetin 3-O robinobioside (181), kaempferol 3-O-rutinoside (182), kaempferol 3-O-glucoside (183), kaempferol 3-O-arabinoside (184)) and one flavonoid (taxifolin (180)). These

Gigantochloa scortechinii Gamble (Buluh Semantan) is one of the most common bamboo species, and abundant with scattered distribution in Peninsular Malaysia. A study was initiated to determine the structure and variation of most ignored part which is rhizome from three different study sites and four consecutive rhizome ages. The study focused on the variation of physiological, anatomical, chemical, and phytochemical attributes in relation to site and rhizome age. This study was conducted at three different locations of Peninsular Malaysia, namely Amanjaya Forest Reserve (Perak), Kenaboi Forest Reserve (Negeri Sembilan), and Ayer Hitam Forest Reserve (Selangor). The sites were selected due to abundant of G. scortechinii bamboo species distribution at those areas, and also represented different climatic condition such as elevation, precipitation, and temperature. The destructive sampling of four consecutive rhizomes of the bamboo species G. scortechinii was conducted using selective random sampling method from healthy clumps. The four consecutive rhizomes were represented as four different rhizome ages: a) new sprout, b) young, c) premature, and d) mature rhizome. The results showed that hydraulics conductivity (K) varied significantly (p<0.01) among study sites, rhizome ages and their interaction (study site x rhizome ages). Significant correlation was found between K with rhizome morphology; such as number of active buds (r = 0.455, p<0.01), number of damaged buds (r = -0.435, p<0.01) and rhizome branches (r = -0.673, p<0.01). Rhizome morphology such as distance between young and old rhizome, rhizome length, number of internode, rhizome diameter (upper, middle, lower, and mean), rhizome lumen diameter (middle, lower, and mean), rhizome wall thickness upper, middle, lower, and mean), and number of buds (total, active and damaged) varied significantly and correlated with study site. However, rhizome lumen diameter at upper portion and rhizome branches were found insign

The oil palm (Elaeis guineensis) is an important crop due to its diverse uses. In Malaysia, the productivity of this crop is hampered with various stresses ranging from biotic to abiotic stresses. Recent studies suggest the importance of signalling molecules in plants in coping against stresses, which includes thiamine (vitamin B1). Thiamine (vitamin B1) is an essential microelement that is synthesised de novo by plants and microorganisms. The active form of thiamine, which is known as thiamine pyrophosphate (TPP), plays a prominent role in metabolic activities particularly as an enzymatic cofactor. Recently, thiamine biosynthesis pathways in oil palm have been characterised but the search of novel regulatory element known as riboswitch is yet to be done. Previous studies showed that thiamine biosynthesis pathway is regulated by RNA element known as riboswitch. Riboswitch binds a small molecule, resulting in a change in production of the proteins encoded by the mRNA. TPP binds specifically to TPP riboswitch to regulate thiamine biosynthesis through a variety of mechanisms and they have been found in archaea, bacteria and eukaryotes. This study was carried out to hunt for TPP riboswitch in oil palm’s thiamine biosynthesis gene. Riboswitch detection software like RiboSW, RibEx, Riboswitch Scanner and Denison Riboswitch Detector were utilised in order to locate putative TPP riboswitch in oil palm ThiC gene sequence that encodes for the first enzyme in the pyrimidine branch of the pathway. The analysis revealed a 192 bp putative TPP riboswitch located at the 3’ untranslated region (UTR) of the mRNA. Further comparative gene analysis showed that the 92-nucleotide aptamer region, where the metabolite binds is conserved inter-species. The secondary structure analysis was also carried out using Mfold Web server and it showed a stem- loop structure manifested with stems (P1-P5) with minimum free energy of -12.26 kcal/mol. Besides that, the interaction of riboswitch and its l

Plants from the genus Calophyllum are known for their rich content of secondary metabolites, especially phenolic compounds such as coumarins, xanthones and flavonoids. Many of these compounds are identified to be the main contributors of the medicinal properties of the plants. Even today, human are still heavily relying on the natural resources to develop new drugs and medicines. The threats of existing and emerging diseases are to be managed by discovering new lead compounds. Natural product research is one of the various approaches to this. This research project aimed to isolate antibacterial compounds which can lead to the discovery of new antibacterial drug candidates for future drug discovery research. Phytochemical studies have been carried out on the stem bark of two selected plant species, Calophyllum andersonii and Calophyllum wallichianum. A total of five xanthones and one terpene were isolated from the hexane and chloroform extracts of Calophyllum andersonii. The terpene is friedelin (79) while the xanthones are macluraxanthone (74), pyranajacareubin (75), calaxanthone I (76), caloxanthone C (77), and euxanthone (78). All of the compounds were isolated for the first time from the plant. Meanwhile, two coumarins and two terpenes were afforded from the hexane and chloroform extracts of Calophyllum wallichianum. The terpenes are friedelin (79) and stigmasterol (82) while the coumarins are wallimarin T (80) and calanolide E (81). Wallimarin T (80) is a new coumarin. The structures of the isolated compounds were identified using spectroscopic methods such as MS, IR and NMR. The plant extracts and two isolated compounds were examined for their antibacterial activities. The samples were tested against four bacterial strains, namely Bacillus cereus, B. megaterium, B. pumilus and B. subtilis. The tests conducted include disc diffusion test, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assay. In the disc diffusion test, wallim

Garcinia is a plant genus from the family Clusiaceae. The genus Garcinia is known to be a rich source of phenolic compounds like xanthones, benzophenones and flavonoids. These compounds were reported to have good biological activities and they have potential to be drug candidates. Garcinia plants are available in our country especially in Sarawak, and many have still yet to be studied. Literature search indicated no previous reports on chemical compounds from Garcinia rostrata. Large scale extractions of the stem bark of G.rostrata and G.nervosa were conducted using conventional solvent extraction method at room temperature for three days. The isolation and purification of the extracts obtained were carried out by a combination of various chromatographic techniques such as vacuum column chromatography, gravity column chromatography and Thin-layer Chromatography (TLC). The structural elucidations of the pure compounds isolated were assisted by numerous spectroscopic methods including Nuclear Magnetic Resonance (NMR), Gas Chromatography-Mass Spectrometry (GC-MS), Infrared Spectroscopy (IR), Ultra Violet Spectroscopy (UV) and also by comparison with literature data. The crude extracts obtained were tested for their anti-bacterial activities. Phytochemical studies on G.rostrata afford six known xanthones: ananixanthone (42), 6-deoxyjacareubin (43), 6-deoxyisojacareubin (44), 8-deoxygartanin (45), 1,7-dihydroxyxanthone (21) and 1,3,7-trihydoxyxanthone (46) along with two common triterpenoids stigmasterol (24) and β-sitosterol (23). Detail chemical studies on Garcinia nervosa led to isolation of one new xanthone, garnerxanthone (47), three known xanthones: 6-deoxyisojacareubin (44), 1,5-dihydroxyxanthone (20) and 12b-hydroxy-des-D-garcigerrin A (32) as well as two common triterpenoids stigmasterol (24) and β-sitosterol (23). The ethyl acetate extracts of both plants and the acetone extract of G.nervosa showed very significant activities against Bacillus subtilis, Bacillus

The genus Calophyllum is consisted of 180-200 species of evergreen trees which are widely distributed in Asia and Africa. This genus is popularly known for their bioactive compounds such as terpenoids, xanthones and coumarins. The need of new drugs are on the rise due to the discovery of various new diseases. Besides, the development of drug resistant diseases also makes drug discovery research significant. Hence, natural products research is important as they provide new templates in the field of drug discovery. Detailed studies were carried out chemically and biologically on the stem bark of two selected plants species, Calophyllum inophyllum and Calophyllum teysmannii. A total of two terpenoid compounds and five xanthones were isolated from the n-hexane and chloroform crude extracts of Calophyllum inophyllum respectively. The terpenoids are friedelin (82) and stigmasterol (83) whereas the xanthones are caloxanthone A (23), caloxanthone B (24),caloxanthone C (43), pyranojacareubin (6) and macluraxanthone (5). On the other hand, a total of two xanthones were isolated from the n-hexane and methanol crude extracts of Calophyllum teysmannii correspondingly namely ananixanthone (29) and β-mangostin (84). The structures of the acquired compounds were elucidated by analyzing the spectroscopic data such as 1D NMR, 2D NMR, IR, and MS. Structural modifications on the parent compound ananixanthone (29) afforded four other new synthesized xanthone derivatives namely ananixanthone monoacetate (85), ananixanthone diacetate (86), 5-methoxyananixanthone (87), and 5-O-benzylananixanthone (88). Their structures were concluded through comparison with the parent compound’s NMR spectra. The crude extracts of both the plants were subjected to toxicity test against LPS stimulated RAW264.7 cells. The results indicated that only chloroform crude extract of Calophyllum inophyllum exhibited a promising result with an IC50 value of 14.81±0.0417 μg/mL. However, the rest of the crude extracts

Phytochemical constituents isolated from the Calophyllaceae andClusiaceae family of plants have gained impressive attention recently due to their amazing potencies in biological activities such as anti-inflammatory, cytotoxicity and anti-bacterial. Coumarins and xanthones discovered from this family have exhibited potent biological activities and some of these compounds have been proposed as lead compounds for drug discovery processes. Nitric oxide plays a vital role in the key molecular signaling constituent involved in inflammatory processes and mass production of NO is one of the main factors that contribute towards chronic degenerative diseases such as cancer and arthritis. It is necessary to find an alternative sources from natural products such as plants as its offer greater hope in the identification of bioactive compounds, less adverse effects and their development into drugs for the treatment of inflammatory diseases. Phytochemical studies such as extraction, isolation and structure elucidation of the isolated compounds with the aid FTIR, GCMS, HRESIMS and NMR were performed on the stem bark of two selected species from the family of Calophyllaceae which are Mesua hexapetala and Mesua beccariana as well on the stem bark of species from the Clusiaceae family which is Garcinia mangostana afforded twenty secondary metabolites, three of which were identified as new compounds. Phytochemical investigation on the stem bark of Mesua hexapetala yielded one new coumarin derivative, hexapetarin (143) together with 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (144), trapezifolixanthone (96), cudraxanthone G ( 19), stigmasterol (7), β-sitosterol (65) and γ-sitosterol (145). These findings are considered novel as no previous reports nor research have been conducted on Mesua hexapetala. Meanwhile, from the stem bark of Mesua beccariana, a new xanthone derivative, beccarixanthone T (146) and a new coumarin derivative, beccamarin T (147) were successfully isolated t

Detailed phytochemical studies on G. mangostana, G. nitida and G. benthamiana have led to the isolation of fourteen compounds, which included four new compounds and ten other compounds. Various chromatographic methods were used in the process of purification of these phytochemical compounds. The structures of these compounds were elucidated by interpreting spectroscopic data obtained from GC-MS, UV, IR, 1D and 2D NMR. The stem bark extracts of G. mangostana furnished ten secondary metabolites, which included three new compounds and seven known compounds. The hexane extract afforded stigmasterol (109) and β-mangostin (100), while the chloroform extract gave cowagarcinone B (101). Isolation work on the ethyl acetate extract yielded two new xanthones, mangaxanthone A (96) and B (97), along with α-mangostin (99), dulcisxanthone F (102), mangostanin (104) and mangostenol (103). The methanol extract gave one new benzophenone, mangaphenone (98). Chromatographic purification of various stem bark extracts of G. nitida resulted in three known compounds from the hexane and chloroform extracts which are stigmasterol (109), osajaxanthone (106) and rubraxanthone (105). The hexane extract of G. benthamianafurnished one known benzophenone, congestiflorone (108) along with one common sterol, stigmasterol (109) and a new benzophenone, benthamianone (107). In silico study was carried out and all the compounds were predicted to effectively induce apoptosis of both cell lines through fatty acid synthase (4PIV). This suggested that all the secondary metabolites would be potential candidates for inhibition of MDA-MB-231 and MCF-7 cells. All the extracts and compounds were subjected to preliminary in vitro screening towards MCF-7, MDA-MB-231 and Vero cell lines. Among all the extracts of these G.species, the ethyl acetate and methanol extracts of G. benthamiana exhibited potent inhibitory effect against MCF-7 and both showed weak cytotoxicities toward Vero cell line. Mangaphenone (98) demo

Harvesting time is a critical factor affecting yield, phytochemical content, physiological and morphological traits of Clinacanthus nutans (Burm. F.) or ‘belalai gajah’ while the quantity and quality of phytochemicals and antimicrobials vary in different parts of the plant. This study investigated the effects of C. nutans vegetative stage and plant parts on bioactive compounds and phytonutrient retentions, the effects of precooling treatment and storage duration on the quality and phytochemicals of C. nutans, the potential use of the vegetative stage and plant part of C. nutans in phytomedicinal preparations using multivariate analysis, and the effect of precooling methods and storage duration on C. nutans with bioactivity correlation. Three-months old C. nutans plants were harvested at young and mature stages, top of the plants for young leaves and stems, bottom parts for mature leaves and stems. The cleaned samples were stored at 0, 2, 4, 6 and 8 days, and evaluated for moisture and chlorophyll contents, colour, microbial contamination, bioactive compounds, and antioxidant activities. Chlorophyll content of young parts especially of leaves was found to be the highest compared to other parts. For colour, young plant parts were brighter compared to the mature plant parts. TPC, TFC, DPPH scavenging activity and FRAP of young leaves were higher as compared to other parts. Bioactive compounds (vitexin, isovitexin, orientin, isoorientin and shaftoside) of young leaves were significantly higher compared to all vegetative stages. Although C. nutans extracts showed no differences in disc diffusion test against Escherichia coli, Bacillus pumilus and Bacillus cereus, the MIC and MBC were stronger in young parts compared to others. Moisture and chlorophyll contents were affected by interaction between precooling (10 ºC for 10 minutes) and storage duration (0, 2, 4, 6 and 8 days), with a quadratic decrease in throughout storage. Total phenolic content and ferric reducing antio

Carbohydrates are the first point of contact in the allergic response pathway, and are thought to heavily regulate the interaction between IgE and mast cells. Several of the groups currently identified to have a role in this process contain N-linked glycans. In this study, various methods for separating N-linked glycans from their peptide backbone were developed to determine which technique released the greatest amount of glycans with the least amount of noise in the resultant mass spectrum. While various mass spectra were obtained, this project focused less on detailing the specifics of the obtained data, but instead sought to determine which method(s) brought about accurate mass spectra (based on previously obtained data) with a high signal-to-noise ratio. Mass spectral data indicates that without proper "pre-separation" techniques, large amounts of high-mass plant material would interfere with analyzing the smaller-mass glycans. Size Exclusion Chromatography (SEC), filtration at the micrometer level, salting out, chemical separations, and mechanical separation via glass beads (all of which can be classified as a "plant material separation") were performed to break down larger pollen protein fragments to smaller units. This was followed by moving on to the "proven method," which worked to separate glycans from their peptide backbone. The "plant material separation" methods are those methods which were tested in order to determine the best way to move forward into the "proven method" of release through permethylation of the glycans. Results indicate that mechanical separation with glass beads followed by the proven method yielded results with a significantly higher amount of released glycans, and less noise in a mass spectrum.

The extravagant and showy inflorescence of torch ginger (Etlingera elatior) with bright colour is suitable to be used as a cut flower. The major weakness of this inflorescence is bract browning that shortens its vase life and reduces marketability. The causes of the bract browning disorder and the timing of its occurrence have not been investigated in detail. Understanding the characteristics of torch ginger and the mechanisms that regulate bract browning is needed for the production of high quality inflorescence. The objective of this work was to assess the potential of torch ginger inflorescence as a cut flower. In study one, the growth and development cycle of torch ginger plant was determined. Results showed that the growth and development cycle of torch ginger plants was divided into vegetative and reproductive phases. The entire inflorescence development period took about 60 days from the inflorescence shoot emergence until blooming stage. In study two, the mechanisms of bract opening and peduncle strength of inflorescence was elucidated. The experiment was conducted in a nested design. Data were analysed using general linear model. The means comparison was performed using Tukey's test. Results showed that fresh weight and respiration rate of inflorescence increased gradually from tight bud to bloom stage. The significant higher respiration rate of inflorescence at bloom stage was coincided with a drastic decrease in soluble sugar content in involucral. This result indicates that soluble sugars depletion is the cause of bract browning. As the inflorescence developed, the cellulose content in involucral and floral bracts decreased significantly. In involucral, the cellulase activity showed a significant increase from tight bud to 6-tip opens stage and decreased thereafter. A significant increase in pectin methylesterase activity was recorded from 6-tip opens to torch shows stage in involucral. In peduncle, the ethanol insoluble residue and cellulose content inc

A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Science, Cross-species hybridization approaches have been used for genetic analysis of species that do not have complete genome arrays available. The study used the cross-species DNA-DNA hybridization approach to characterize Ximenia americana biological processes. Preliminary micro-array studies done in the Department of Chemistry and Biochemistry at the University of Namibia has created X. americana DNA-DNA hybridization to a well-known Arabidopsis thaliana genechip (ATH1). A. thaliana probe-pairs that hybridised to the X. americana genomic DNA on the basis of the perfect-match (PM) probe signal were selected and analysed using a cel file parser script to generate a new high density probe mask files. These files effectively represent the first ever X. americana DNA-DNA hybridisation data. This study conducted gene ontology analysis of X. americana/A. thaliana hybridisation data. Such gene ontology analysis demonstrated that abiotic stress response genes are over-represented in relative comparison to model species A. thaliana under natural conditions. This observation was independently confirmed with PCR amplification of the following orthologous genes using X. americana genomic DNA: AT4G15910.1, SAD2, HXK1, ACC and ERF/AP2. Given the lack of genomic sequence information in X. americana background, primers for genomic amplification was design using A. thaliana genomic sequence information. Primers where designed to yield 100 bp genomic PCR product. Each of the selected genes was successfully amplified hence giving evidence of homology within primer binding sites. Nonetheless, the genomic amplification of these key abiotic factors in X. americana confirms the type of responses that supports the adaptation of X. americana under natural conditions that are stress related (heat and drought stress). Although transcript levels of this important abiotic response factors could not be measured in absolute or relative terms, the study demonstrated inherent presence of such genes at t

Medicinal plants are part of indigenous people‟s cultural heritage, thus since ancient times treatment of various diseases using medicinal plants has been part of human culture. The value of medicinal plants to mankind has been very well proven. It is estimated that 70% to 80% of people worldwide rely mainly on traditional health care systems, especially on herbal medicines (Stanley and Luz, 2003). In many societies the medicinal properties of plants were discovered mostly through trial and error, but use was also influenced by the belief systems of the people involved and often became entangled with religious and mythical practices (Mathias et al., 1996). Besides that, medicinal plants are proving to be rich resources of constituents that can be used in drug development and synthesis. Medicinal plants have been a source of a wide variety of biologically active compounds for many centuries and have been used extensively as crude material or as pure compounds for treating various disease conditions. Between 1% and 10% of plants out of an estimated 250 000 to 500 000 species of plants on earth are used by humans (Boris, 1996). 2 Plants used for medicinal purposes contribute significantly to the development of major medical drugs that are used today. Most common medicines have compounds extracted from plants as their primary active ingredients and many have provided blueprints for synthetic or partially synthesized drugs (Simpson and Ogorzaly, 2001). There has been a major resurgence of interest in traditionally used medicinal plants, with a number of international and local initiatives actively exploring the botanical resources of southern Africa with the intention to screen indigenous plants for pharmacologically active compounds (Gurib-Fakim et al., 2010; Rybicki et al., 2012). South Africa is considered a “hot spot” for biodiversity and more than 22 000 plant species occur within its boundaries. This represents 10% of the world‟s species, although the land surface

A general growing awareness of healthy lifestyle increased the interest of the food industry in the market of high fiber products. Rice bran, an agro-byproduct obtained from outer rice layers, could offer a new variety of baked goods with high fiber content. However, bran supplementation usually can cause severe problems to the quality of final products. Thus, supplementation with bran requires changes in processing techniques for the production of baked goods with good consumer quality. One of the techniques being employed is fermentation and this study was carried out to optimize the fermentation conditions of rice bran sourdough. This was then followed by evaluation of the rice bran sourdough functionality. Rice bran used in this study contained 10.9% moisture, 16.1% fat, 12.7% protein, 8.8% ash, 22.4% insoluble dietary fiber, 1.3% soluble dietary fiber and 27.8% carbohydrate. The use of lactic acid bacteria (LAB) and yeast starter cultures in the fermentation process resulted in slight differences among the fermentative end product characteristics of the sourdough. These characteristics were highly influenced by the LAB strains used. Lactobacillus plantarum was better than Lactobacillus brevis and Lactobacillus sanfranciscencis at producing the desired pH, total titratable acidity (TTA), organic acids, fermentation quotient and soluble sugars required in sourdough preparation. A response surface methodology (RSM) and central composite design (CCD) were employed to obtain the optimum fermentation conditions for obtaining acidic properties and antioxidant phenolic compounds in rice bran sourdough incorporated with Lactobacillus plantarum. The acidity values found showed that the fermentation temperature and time at 33°C and 12.5 hours, respectively, were able to produce optimum pH (pH 3.5 to 4.5) and total titratable acidity (16 to 22 ml of 0.1M NaOH). Total phenolic compounds increased in parallel with increasing fermentation temperature and time. Rice bran sourd

Els residus industrials generen un problema mediambiental i econòmic, per tant, el seu reaprofitament pot generar, a més a més de beneficis per a l’alimentació, també beneficis econòmics. La llavor de l’alvocat es un residu que es produeix a partir de la fabricació de certes salses com per exemple, “guacamole”, cada vegada amb més importància a la cuina europea. L’aprofitament d’aquests residu com a conservant natural d’aliments, pot considerar-se com a una de les seves sortides, donat que la capacitat antioxidant d’aquesta llavor podria ser capaç d’allargar la vida útil d’aliments susceptibles d’oxidar-se. L’objectiu d’aquest assaig es quantificar la capacitat antioxidant mitjançant diverses tècniques, com l’assaig de capacitat antirradicalària, els polifenols totals, i el test sobre una matriu càrnia . S’han extret els agents antioxidants, majoritàriament polifenols, a través d’extraccions amb metanol, i diferents temps d’extracció, aplicant el mètode de superfície de resposta. La millor condició està al voltant de 80ºC, 55% de metanol i agitació durant 20 minuts. Les mostres estudiades han presentat una capacitat antioxidant sobre una matriu càrnia, alentint l’oxidació i augmentant el temps de vida útil fins a 6 dies més. Tots els experiments demostren que l’extracte obtingut del residu de la llavor d’alvocat es un bon sustitut d’antixodants sintètics.

The Meliaceae family, comprising of about 1400 species, is an important source of limonoids and tetranortriterpenoids. Aglaia is one of the genus within the family which has been the focus of phytochemical investigations due to its interesting biological activities. Certain species of Aglaia have traditionally been used for their medicinal and healing properties, such as for the treatment of fever, diarrhoea, inflammation and wounds. Although there has been many previous investigations on the genus, thus far, the species A. macrophylla has not been put through any phytochemical investigation. This species is a common species in Peninsular Malaysia. This work describes the phytochemical investigation on the methanolic bark extract of Aglaia macrophylla, leading to the isolation and identification of three new apotirucallane triterpenoids in addition to a known seco-limonoid. All compounds were identified by a combination of spectroscopic methods including UV, IR, 1D and 2D NMR and ESI-MS as well as comparison with literature data. The air-ground barks of Aglaia macrophylla were cold extracted by macerating in MeOH for several hours and repetitive cycles. The concentrated methanolic extract was partitioned into hexane, ethyl acetate and aqueous fractions. The hexane and ethyl acetate fractions were subjected to various chromatographic procedures which included vacuum liquid chromatography (VLC), column chromatography (CC) and finally, repetitive semi-preparative High Performance Liquid Chromatography (HPLC). The bark extract yielded four triterpenoids, one of which is a known seco-protolimonoid with a hemiacetal C-17 side chain, identified as methyl-1,7-diacetoxy-23,24,25-trihydroxy-20,21,24-epoxy-3,4-seco-apotirucall-4(28),14(15)-diene-3-oate (56). The compound is a constituent of another Meliaceae species, Trichilia elegans. The other three compounds (57, 58 and 59) are new, all possessing the same 3-oxoapotirucallane skeleton and carrying highly oxygenated C-17 sid

Phytochemical studies carried out on Mesua beccariana, Mesua ferrea and Mesua congestiflora (Clusiaceae) resulted in the isolation of eight new compounds together with twelve known compounds. Different kinds of chromatographic techniques were utilized for the purification of these isolated compounds. The characterizations of these compounds were achieved through a variety of spectroscopic techniques such as 1D and 2D NMR, UV, IR and GC-MS. The stem bark of Mesua beccariana furnished four new compounds which are two xanthones, mesuarianone (236) and mesuasinone (237), a coumarin, beccamarin (238) and a cyclodione, mesuadione (239), along with several known compounds including two anthraquinones, 4-methoxy-1,3,5-trihydroxyanthraquinone (240) and 2,5-dihydroxy-1,3,4-trimethoxy anthraquinone (241) as well as a xanthone 6-deoxyjacareubin (116). Meanwhile, seven xanthones were isolated from the root bark of Mesua ferrea three of which are new: mesuaferrin A (242), mesuaferrin B (245) and mesuaferrin C (243). Four known compounds were identified as caloxanthone C (244), macluraxanthone (87), 1,5-dihydroxyxanthone (70) and tovopyrifolin C (246). Meanwhile, chemical investigations on Mesua congestiflora afforded a new benzophenone, congestiflorone (247) together with a known xanthone α-mangostin (106). Several triterpenoids and sterols were obtained from the three Mesua species including friedelin (183), betulinic acid (248), stigmasterol (187) and β-sitosterol (188). Structural modifications were carried out on several major compounds which were mesuarianone (236), beccamarin (238), caloxanthone C (244) and congestiflorone (247). The acetylation of mesuarianone (236) afforded both the mono and diacetate derivatives which were identified as mesuarianone acetate A (249) and mesuarianone dwiacetate B (250). However, the acetylation reactions of other major compounds only successfully yielded beccamarin acetate (251), caloxanthone C dwiacetate (252) and congestiflorone acetate

Dysoxylum grande was chosen to be studied due to the lack of reported scientific investigations on the plant and interesting phytochemical findings on another plant of the same genus, Dysoxylum acutangulum. Two biological activities; antiacetylcholinesterase and ichthyotoxicity were used as the bioassay in guiding the fractionation step. As a result, nine compounds were isolated from the ichthyotoxic EtOAc leaves fraction. Among them, eight were identified as new compounds named as 20S,24R-epoxy-7 ,25-dihydroxy-3,4-secodammar-4(28)-en-3-oic acid (CP1), grandol A (CP2), grandol B (CP3), grandol C (CP4), grandol D (CP5), grandol E (CP8), grandol F (CP9) and grandol G (CP10) and the known compound was identified as -sitosteryl- -D-glucopyranoside (CP11). All new compounds were identified based on thorough analysis of spectroscopic data including 1D and 2D NMR. The structure for the known compound was established by spectral data analyses and by comparison with reported investigations. In ichthyotoxic assay carried out on Zebra fish (Danio rerio), EtOAc fraction (leaves) was found to possess significant ichthyotoxicity compared to other fractions. However, the isolated pure compounds did not provide any IC50 values for the ichtyotoxicity test due to their limited amounts. All compounds were tested for anti-acetylcholinesterase activity using Thin Layer Chromatography (TLC)-bioautography with fast blue B salt. Only grandol A (CP2) and grandol B (CP3) showed positive results. However, the obtained IC50 for both of these compounds, grandol A (CP2) and B (CP3), using Ellman’s method was not significant (>200 μg/mL).

Els residus industrials generen un problema mediambiental i econòmic, per tant, el seu reaprofitament pot generar, a més a més de beneficis per a l’alimentació, també beneficis econòmics. La llavor de l’alvocat es un residu que es produeix a partir de la fabricació de certes salses com per exemple, “guacamole”, cada vegada amb més importància a la cuina europea. L’aprofitament d’aquests residu com a conservant natural d’aliments, pot considerar-se com a una de les seves sortides, donat que la capacitat antioxidant d’aquesta llavor podria ser capaç d’allargar la vida útil d’aliments susceptibles d’oxidar-se. L’objectiu d’aquest assaig es quantificar la capacitat antioxidant mitjançant diverses tècniques, com l’assaig de capacitat antirradicalària, els polifenols totals, i el test sobre una matriu càrnia . S’han extret els agents antioxidants, majoritàriament polifenols, a través d’extraccions amb metanol, i diferents temps d’extracció, aplicant el mètode de superfície de resposta. La millor condició està al voltant de 80ºC, 55% de metanol i agitació durant 20 minuts. Les mostres estudiades han presentat una capacitat antioxidant sobre una matriu càrnia, alentint l’oxidació i augmentant el temps de vida útil fins a 6 dies més. Tots els experiments demostren que l’extracte obtingut del residu de la llavor d’alvocat es un bon sustitut d’antixodants sintètics.

Capillary electrophoresis (CE) has been used increasingly more over the last decade in the area of food analysis. Numerous food products and food components have been analysed using this technique because of its high efficiency and short separation times. However, the inherent lack of detection sensitivity in CE combined with the complex matrices present in many food samples, especially those of plant origins, is one of the contributing factors to the limited development on CE in this particular area of food analysis. In this project, the potential of CE as a tool in the analysis of vegetables belonging to the family Brassica oleracea was investigated. Capillary zone electrophoresis (CZE), the most frequently used CE mode in food analysis, has been employed to quantitatively determine the phenolic acids present in vegetables of B. oleracea. A simple and rapid CZE method for the baseline resolution of four hydroxycinnamic acids was developed. Peak efficiencies and separation time were optimised by adjustment of the borate buffer concentration (15 mM sodium tetraborate pH 9.13) with the optimum method having a separation time of 7 min with detection limits ranging from 1.1 to 2.3 mg/kg of vegetables. The developed CZE method was applied to resolve the key flavonoids in broccoli extracts, however, detection sensitivity was poor for these compounds. To overcome this limitation an online pre-concentration method, large volume sample stacking (LVSS), was used to enable quantitative determination of flavonols in broccoli. This LVSS-CZE method allowed for the separation of two flavonols, kaempferol and quercetin, within 8 min with average enhancement factors of approximately 20 when compared to the original CZE method, giving detection limits of 0.6 and 0.9 mg/kg of broccoli. Resolution of the two flavonols was optimised by varying the borate buffer concentration and pH (the optimum values are 10 mM sodium tetraborate pH 8.40) and by using a longer capillary (85 cm). Differ

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1980, In the New England rocky intertidal community, space is dominated by two perennial plant types, brown fucoid algae (Ascophyllum nodosum and several species of Fucus) in the mid zones and the red alga Chondrus crispus in the low zones. These algae are not grazed by the predominant herbivorous snail, Littorina littorea. Here I report the first direct evidence that these algae produce chemicals which inhibit feeding by the snails. Polyphenols in Fucus vesiculosus and Ascophyllum nodosum were shown to be effective chemical defenses against the snails. Feeding experiments demonstrated that the presence in the diet of as little as 1% polyphenol (dry weight), extracted from these two algal species, caused a significant reduction in feeding by L. littorea; 10% polyphenol (dry wt.) in food media inhibited snail feeding nearly 100%. The phenol and polyphenol contents in different tissues of these two algal species and in other New England rocky intertidal algal species were monitored monthly for one year. F. vesiculosus and A. nodosum showed highest polyphenol contents (1-17% dry wt.); these levels were sufficiently high in all tissues during all months to inhibit snail feeding. The mechanism of action of plant polyphenols against herbivores is through their binding to plant proteins and other nitrogenous compounds, rendering them indigestible. Polyphenol contents were therefore examined in relation to plant nitrogen contents (using polyphenol/nitrogen ratios) to estimate the unavailability of plant nitrogen to herbivores due to polyphenol binding. Annual brown algal species such as Petalonia fascia and Scytosiphon lomentaria had significantly lower levels of phenols and polyphenols than the perennial F. vesiculosus and A. nodosum. These two species are highly preferred as food by L. littorea. C. crispus and the green alga Codium fragile also had low phenol and polyphenol levels, yet they are of low food preference to the snails. Methylene chloride extracts from C. crispus an, Financial support for my research was provided by the National Science Foundation (Grant OCE 78-111573) and the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in Biological Oceanography.

""Echinacea" and "Spilanthes" are popular over-the-counter herbal supplements derived from raw tissue or tissue extracts from plants such as Echinacea purpurea and Spilanthes acmella, respectively. Several chemical constituents have been identified as possible candidates for these plants' supposed medicinal activities, and include the "alkylamides," of which dienyl and diynyl analogs are prominent members. Isolation of these compounds from the plants is often difficult and results in poor yields. The goal of our research was to develop an encompassing synthesis scheme for dienyl and diynyl alkylamides (Figure 1) addressing consistent functional groups, using a Wittig reaction, a Horner-Wadsworth-Emmons reaction and a Sonogashira reaction. The total syntheses for these compounds are not novel, but have been known to be rather lengthy procedures. We are pleased to offer a novel synthesis that can synthesize a derivative of Spilanthol which involves only three reactions and well developed method for the diynyl structures using the Sonogashira coupling reaction."--Abstract from author supplied metadata.

The objectives of the study are to isolate, and identifl the phenolic compounds present in the palm oil mill effluent (POME) and evaluate their antioxidative activity. Combinations of column and partition chromatography were used in the isolation of the phenolic compounds. Antioxidative activities of the POME hctions were evaluated for fke radical scavenging activity, lipid thiocyanate, &carotene-linoleate and reducing assays. Identification of the phenolic compounds in POME filtrate was carried out using high performance liquid chromatography (HPLC), followed by confirmation of the compounds using gas chromatography mass spectrometry (GCIMS) and liquid chromatography mass spectrometry (LCIMS). The study revealed the presence of cinnamic acid derivatives, which were measured at 320 nm. These included chlorogenic, p-cournaric, caffeic, ferulic acids and rutin hydrate. Benzoic acid derivatives, which were identified as protocatechuic, gentisic, p-hydroxybenzoic and vanillic acids were also present when measured at 260 nrn. Hydrolysis of the sample did not affect the chromatographic pattern obtained indicating the stability of the phenolic compounds in the POME filtrate. Flavan-3-01 groups (catechins) were identified from ytterbium precipitation method. Four fractions have been isolated from POME filtrate based on flash chromatography coupled with uv/vis detection. The antioxidative activity of each h t i o n was then evaluated. All the POME fractions demonstrated excellent antioxidative activity in all the assays used. This is especially true for both Fractions 3 and 4. Fraction 1 exhibited highest antioxidative activity based on reducing assay followed by Fraction 3 indicating the excellent metal chelating ability of the phenolics in these hctions. The POME fractions were found to contain different levels of total phenolics, which did not necessarily correspond to the strength of antioxidative activity, measured for each hction. Fraction 3 showed strong free radical

Chan Hiu-ki., Thesis (M.Phil.)--Chinese University of Hong Kong, 2000., Includes bibliographical references (leaves 97-112)., s in English and Chinese., Thesis Committee --- p.i, 摘要 --- p.ii, p.iii, Acknowledgements --- p.v, Abbreviations --- p.vi, Table of Contents --- p.vii, List of figures --- p.xi, List of tables --- p.xiii, Chapter Chapter 1 --- Literature Review --- p.1, Chapter 1.1 --- Nitrogen assimilation in plants --- p.1, Chapter 1.2 --- Importance of asparagine in plants --- p.5, Chapter 1.3 --- Enzymatic reaction of asparagine synthetase (AS) --- p.8, Chapter 1.4 --- Asparagine synthetase of non-plant organisms --- p.10, Chapter 1.5 --- Biochemistry background of plant asparagine synthetases --- p.12, Chapter 1.6 --- Molecular studies of asparagine synthetase genes in plants --- p.15, Chapter 1.7 --- Arabidopsis thaliana as a model plant --- p.24, Chapter 1.8 --- ASN studies in Arabidopsis thaliana --- p.24, Chapter 1.9 --- Hypothesis --- p.27, Chapter Chapter 2 --- Materials and Methods --- p.29, Chapter 2.1 --- Chemicals --- p.29, Chapter 2.2 --- Plant materials and growth conditions --- p.29, Chapter 2.2.1 --- Surface sterilization of Arabidopsis seeds --- p.29, Chapter 2.2.2 --- "Growth conditions of Arabidopsis seeds for total RNA extraction, enzyme assay, chlorophyll content measurement and dry weight measurement" --- p.30, Chapter 2.3 --- Agrobacterium mediated transformation via vacuum infiltration method --- p.30, Chapter 2.3.1 --- Principles --- p.30, Chapter 2.3.2 --- Plant materials and bacterial strains of Agrobacterium mediated transformation --- p.31, Chapter 2.3.2.1 --- Plant materials --- p.31, Chapter 2.3.2.2 --- Gene constructs --- p.31, Chapter 2.3.2.2 --- Bacterial strains --- p.32, Chapter 2.3.3 --- Agrobacterium mediated transformation via vacuum infilitration --- p.32, Chapter 2.4 --- Screening of transformants --- p.33, Chapter 2.5 --- DNA and RNA manipulation --- p.34, Chapter 2.5.1 --- DNA extraction and quantitation --- p.34, Chapter 2.5.2 --- PCR amplification and detection of transgenes --- p.36, Chapter 2.5.2.1 --- PCR amplification and detection of transgenes --- p.36, Chapter 2.5.2.2 --- Primer sequence --- p.37, Chapter 2.6 --- RNA analysis of transormants --- p.38, Chapter 2.6.1 --- General introduction --- p.38, Chapter 2.6.2 --- RNA extraction --- p.39, Chapter 2.6.3 --- Making single-strand DIG PCR probes --- p.40, Chapter 2.6.4 --- Quantitation of single-strand DIG-labeled probes --- p.42, Chapter 2.7 --- Northern blot analysis --- p.42, Chapter 2.7.1 --- Detection --- p.43, Chapter 2.7.2 --- Film development --- p.43, Chapter 2.8 --- "Amino acid, protein, dry weight and total nitrogen analysis" --- p.43, Chapter 2.8.1 --- Extraction of free amino acids --- p.43, Chapter 2.8.2 --- Protein assay --- p.44, Chapter 2.8.3 --- Determination of nitrogen and carbon content in seeds --- p.45, Chapter 2.8.4 --- Dry weight measurement --- p.45, Chapter 2.8.5 --- Seed storage protein analyses --- p.45, Chapter 2.8.6 --- Detection of chlorophyll content --- p.46, Chapter 2.9 --- Asparagine synthetase activity analysis --- p.46, Chapter 2.9.1 --- Crude extracts preparation --- p.46, Chapter 2.9.2 --- AS enzyme assay --- p.47, Chapter 2.9.3 --- Asparagine content measurement --- p.47, Chapter 2.10 --- In situ hybridization --- p.48, Chapter 2.10.1 --- Making cRNA probe --- p.48, Chapter 2.10.2 --- In situ hybridization --- p.48, Chapter Chapter 3 --- Results --- p.50, Chapter 3.1 --- Construction of ASN1 overexpressing lines --- p.50, Chapter 3.2 --- Changes in nitrogen status during vegetative growth of ASN1 overexpressing lines --- p.53, Chapter 3.3 --- Changes in nitrogen status during seed development of ASN1 overexpressing lines --- p.55, Chapter Chapter 4 --- Discussion --- p.76, Chapter Chapter 5 --- Conclusion --- p.85, Chapter Chapter 6 --- Perspective --- p.86, Appendix --- p.87, References --- p.97, http://library.cuhk.edu.hk/record=b5890346, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

English: Berchemia zeyheri is known for its unique red heartwood, a property that was probably responsible for the first phytochemical investigation into the flavonoid content of this tree. The heartwood contains a unique series of biflavonoids with one of more benzofuranoid moieties. These are usually found in diastereomeric mixtures, the biogenetic origin and stereochemistry of which have hitherto been unknown. This investigation thus represents a renewed effort to solve some of the intricate problems associated with these compounds. The high concentration of maesopsin in the heartwood made extensive enrichment and fractionation by the use of Craig countercurrent distribution techniques and Sephadex LH- 20 gelchromatography necessary. The two diastereomers of 4',5, 7-tri-O-methylnaringenin-(3a~ 7)-2,4,4',6-tetra-Omethylmaesopsin were, for the first time, successfully isolated and separated. Reduction of these diastereomers with Na(CN)BH3 gave two enantiomeric pure fragments. The conformations of the heterocyclic rings of these fragments were established by molecular mechanics (MMX and GMMX) and semi-empirical methods (AMI). These results allowed the absolute configuration of the fragments to be deduced from CD-curves of the compounds by application of Snatzke's rule for a,~-unsaturated five-membered cyclic rings. A n.O.e. correlation observed for one of the diastereomers only, correlates the stereocenter of the maesopsin moiety, of known absolute configuration, with a specific configuration of the naringenin unit, thus defining the absolute configuration of the dimer. These results also allowed the determination of the absolute stereochemistry of two regioisomers of the above dimers, 4',5, 7-tri-O-methylnaringenin-(3a~5)-2,4,4',6-tetra-Omethylmaesopsin and its epimer. The 13CNMR spectra of these related dimers were also studied and fully elucidated by means of HMQC and HMBC experiments. The structure and stereochemistry of two novel isoflavanone-benzofuranone bifl, Afrikaans: Berchemia zeyheri is bekend vir 'n unieke rooi kernhout, 'n eienskap wat aanvanklik verantwoordelik was vir die eerste fitochemiese ondersoek op hierdie houtsoort. Die kernhout bevat o.a. 'n unieke reeks biflavonoïede met een of meer bensofuranoïedeenhede wat kenmerkend as diastereomeriese mengsels aangetref word. Die oorsprong van die diastereomeriese aard van hierdie mengsels, asook die stereochemie van die verbindings, kon tot op hede egter nog nie bepaal word nie. Na aanleiding hiervan is 'n herondersoek na die flavonoïedinhoud van Berchemia zeyheri aangepak. Die hoë konsentrasie maesopsin in die kernhout het uitgebreide verryking en fraksionering deur benutting van o.a. Craig teenstroomverdelingstegnieke en Sephadex LH-20 jelchromatografie genoodsaak. Die twee diastereomere van 41,5,7-tri-O-metielnaringenin-(3a~7)-2,4,4',6-tetra-Ometielmaesopsin is vir die eerste keer suksesvol geïsoleer en geskei. Reduksie van hierdie diastereomere met Na(CN)BH3 gee aanleiding tot twee suiwer enantiomeriese brokstukke. Die konformasie van die heterosikliese ring van hierdie brokstukke is m.b.v. molekulêre meganika (MMX en GMMX) en semi-empiriese metodes (AMI) bepaal. Na aanleiding van hierdie resultate kon die absolute konfigurasie van die fragmente m.b.v. van Snatzke se reël vir a,p-onversadigde vyfledige sikliese ketone vir die eerste keer uit die SD-kurwes bepaal word. 'n N.O.e. korrelasie wat slegs byeen diastereomeer waargeneem is, korreleer die stereosentrum van die maesopsineenheid met 'n bepaalde konfigurasie van die naringenineenheid en gee toegang tot die absolute konfigurasie van die dimere. Hierdie resultate laat ook die bepaling van die absolute stereochemie van 4',5,7-tri-Ometielnaringenin-( 3a~5)-2,4,4',6-tetra-O-metielmaesopsin en sy epimeer, twee regioisomere van die bogenoemde dimere, toe. Die 13CKMR spektra van hierdie dimere is ook bestudeer m.b.v. HMQC en HMBC eksperimente. Die stuktuur en stereochemie van twee unieke isoflavanoon-bensofuranoon

Since the introduction of thirty Australian brushtail possums into New Zealand in 1858 to start a fur trade industry the possum population has grown considerably. New Zealand is now 'home' to approximately 70 million possums which wreak devastation on our native forests and wildlife. Current effective strategies for the control of possums in uninhabited areas include the use of 1080, brodifacoum, cholecalciferol, cyanide, and trapping or shooting. However these strategies are relatively non-specific in their mode of action and as such cause non-target species, including native wildlife, to die. The use of non-specific toxins and traps is also inappropriate for situations where people, livestock, or pets are present. There is therefore a demand for alternative strategies of possum control that affect only the target species. Methods presently being researched include the development of contraceptive vaccines, possum repellents and possum specific bait stations. This research investigates the feasibility of developing a cyanogenic bait that is activated by a co-factor within the possum diet. The fast acting hydrogen cyanide poison is present in some plants species in an inactive glycoside form. Upon tissue injury the inactive cyanogenic glycoside is exposed to and hydrolysed by catabolic enzymes within the plant thereby releasing the toxin, hydrogen cyanide, at potentially lethal levels for possums. Some plant varieties within cyanogenic species however, have evolved to be acyanogenic due to the absence of either the cyanogenic substrate, the enzyme, or both. The occurrence of these acyanogenic plants which contain either the substrate or the appropriate enzymes are the target of this research. It is these plants that may provide the necessary co-factor for a cyanogenic possum bait to become lethal. Preliminary analyses involved measuring and maximising the cyanide release from plant species known to be highly cyanogenic. Clover leaves (Trifolium repens), cherries (Pr