Differing mechanisms of simple nitrile formation on glucosinolate degradation in Lepidium sativum and Nasturtium officinale seeds.

Glucosinolates are sulphur-containing glycosides found in brassicaceous plants that can be hydrolysed enzymatically by plant myrosinase or non-enzymatically to form primarily isothiocyanates and/or simple nitriles. From a human health perspective, isothiocyanates are quite important because they are major inducers of carcinogen-detoxifying enzymes. Two of the most potent inducers are benzyl isothiocyanate (BITC) present in garden cress (Lepidium sativum), and phenylethyl isothiocyanate (PEITC) present in watercress (Nasturtium officinale). Previous studies on these salad crops have indicated that significant amounts of simple nitriles are produced at the expense of the isothiocyanates. These studies also suggested that nitrile formation may occur by different pathways: (1) under the control of specifier protein in garden cress and (2) by an unspecified, non-enzymatic path in watercress. In an effort to understand more about the mechanisms involved in simple nitrile formation in these species, we analysed their seeds for specifier protein and myrosinase activities, endogenous iron content and glucosinolate degradation products after addition of different iron species, specific chelators and various heat treatments. We confirmed that simple nitrile formation was predominantly under specifier protein control (thiocyanate-forming protein) in garden cress seeds. Limited thermal degradation of the major glucosinolate, glucotropaeolin (benzyl glucosinolate), occurred when seed material was heated to >120 degrees C. In the watercress seeds, however, we show for the first time that gluconasturtiin (phenylethyl glucosinolate) undergoes a non-enzymatic, iron-dependent degradation to a simple nitrile. On heating the seeds to 120 degrees C or greater, thermal degradation of this heat-labile glucosinolate increased simple nitrile levels many fold.

Synthesis, Binding and Bioactivity of [gamma]-Methylene [gamma]-Lactam Ecdysone Receptor Ligands: Advantages of QSAR Models for Flexible Receptors

Nuclear hormone receptors, such as the ecdysone receptor, often display a large amount of induced fit to ligands. The size and shape of the binding pocket in the EcR subunit changes markedly on ligand binding, making modelling methods such as docking extremely challenging. It is, however, possible to generate excellent 3D QSAR models for a given type of ligand, suggesting that the receptor adopts a relatively restricted number of binding site configurations or [`]attractors'. We describe the synthesis, in vitro binding and selected in vivo toxicity data for [gamma]-methylene [gamma]-lactams, a new class of high-affinity ligands for ecdysone receptors from Bovicola ovis (Phthiraptera) and Lucilia cuprina (Diptera). The results of a 3D QSAR study of the binding of methylene lactams to recombinant ecdysone receptor protein suggest that this class of ligands is indeed recognized by a single conformation of the EcR binding pocket.

Pre-cropping with canola decreased Pratylenchus thornei populations, arbuscular mycorrhizal fungi, and yield of wheat.

Root-lesion nematode (Pratylenchus thornei) significantly reduces wheat yields in the northern Australian grain region. Canola is thought to have a 'biofumigation' potential to control nematodes; therefore, a field experiment was designed to compare canola with other winter crops or clean-fallow for reducing P. thornei population densities and improving growth of P. thornei-intolerant wheat (cv. Batavia) in the following year. Immediately after harvest of the first-year crops, populations of P. thornei were lowest following various canola cultivars or clean-fallow (1957-5200 P. thornei/kg dry soil) and were highest following susceptible wheat cultivars (31 033-41 294/kg dry soil). Unexpectedly, at planting of the second-year wheat crop, nematode populations were at more uniform lower levels (<5000/kg dry soil), irrespective of the previous season's treatment, and remained that way during the growing season, which was quite dry. Growth and grain yield of the second-year wheat crop were poorest on plots previously planted with canola or left fallow due to poor colonisation with arbuscular mycorrhizal (AM) fungi, with the exception of canola cv. Karoo, which had high AM fungal colonisation and low wheat yields. There were significant regressions between growth and yield parameters of the second-year wheat and levels of AMF following the pre-crop treatments. Thus, canola appears to be a good crop for reducing P. thornei populations, but AM fungal-dependence of subsequent crops should be considered, particularly in the northern Australian grain region.

Develop added value uses of high anti-bacterial honey

Honey is valued for its medicinal properties. There interest from industry to develop a rapid method to detect the bioactivity of honey and also to develop value added products from high antibacterial honey.

Synthesis and biological evaluation of novel 1-(4-methoxyphenethyl)-1H-benzimidazole-5-carboxylic acid derivatives and their precursors as antileukemic agents

We report here the synthesis and preliminary evaluation of novel 1-(4-methoxyphenethyl)-1H-benzimidazole-5-carboxylic acid derivatives 6(a–k) and their precursors 5(a–k) as potential chemotherapeutic agents. In each case, the structures of the compounds were determined by FTIR, 1H NMR and mass spectroscopy. Among the synthesized molecules, methyl 1-(4-methoxyphenethyl)-2-(4-fluoro-3-nitrophenyl)-1H-benzimidazole-5-carboxylate (5a) induced maximum cell death in leukemic cells with an IC50 value of 3 μM. Using FACS analysis we show that the compound 5a induces S/G2 cell cycle arrest, which was further supported by the observed down regulation of CDK2, Cyclin B1 and PCNA. The observed downregulation of proapoptotic proteins, upregulation of antiapoptotic proteins, cleavage of PARP and elevated levels of DNA strand breaks indicated the activation of apoptosis by 5a. These results suggest that 5a could be a potent anti-leukemic agent.

ACIAR Productivity and profitability enhancing tropical pulses in Indonesia and Australia

The project aims at improving the productivity and profitability of mung beans, soy beans and peanuts.

Reproductive variation in naturally occurring populations of the weed Parthenium hysterophorus (Asteraceae) in Australia

Parthenium weed, an annual herb native to tropical America, causes severe economic, human, and animal health and environmental impacts in Australia and in many countries in Asia, Africa, and the Pacific. There is little known about variation in reproductive output in naturally occurring populations of this weed. This information is vital to develop plant population models, devise management strategies to reduce seed output, and formulate parthenium weed pollen-induced human health (e.g., dermatitis and hay fever) risk assessment. Here, the variations in the number of capitula produced by the parthenium weed at two sites in Queensland, Australia, over a 4-yr period are reported. Under field conditions, parthenium weed produced up to 39,192 capitula per plant (> 156,768 seeds per plant), with majority of the plants (approximate to 75%) producing between 11 and 1,000 capitula, and less than 0.3% of the plants producing more than 10,000 capitula (> 40,000 seeds per plant). The number of capitula per plant in the field (297 +/- 22) was much lower than those reported from glasshouse and laboratory studies. Plant biomass contributed to 50 to 80% of the variation in capitulum production between plants within plots at each site, and weed density accounted for 62 to 73% of the variation in capitulum production between plots within each site. As plant size is directly correlated with reproductive output, plant size distributions in parthenium weed can be used to estimate effective population size. Information on variation in reproductive output will be used to implement management strategies to reduce parthenium weed seed output, resulting in reduced soil seed bank and weed seed spread.

Biological control of Mikania micrantha in Papua New Guinea and Fiji using the rust fungus Puccinia spegazzinii

Mikania micrantha Kunth (Asteraceae), commonly known as ‘mile-a-minute’, is a neotropical plant species now found in 17 Pacific island countries and territories, invading small cropping areas and plantations, thereby reducing productivity and food security. In 2006, a biocontrol project on M. micrantha commenced in Fiji and Papua New Guinea (PNG). The distribution of M. micrantha as well as baseline data such as plant growth rates and socio-economic impacts were determined before the importation of any biocontrol agents. Mikania micrantha was recorded in all 15 lowland provinces in PNG and on all major islands in Fiji. Plants grow about 3.2cm/day in PNG and about 1.9cm/day in Fiji. A socio-economic survey, involving over 370 respondents in over 220 villages from 15 provinces in PNG, found that 78% of respondents considered M. micrantha a serious weed and about 44% had M. micrantha, which they needed to weed at least fortnightly, in over a third of their land. Over 80% of respondents used slashing and/or handpulling as the preferred method of weed control. About 40% of respondents considered that M. micrantha reduced crop yield by more than 30%. In Fiji, 52 respondents from four islands participated in the survey. Over 60% of respondents in Fiji considered M. micrantha a serious weed and 23% had about 30% of their farm lands infested with the weed. Only 15% of respondents needed to weed at least fortnightly, with 56% using slashing and/or hand-pulling as the preferred means of control. Over 65% of respondents estimated that they lost at least 30% of potential crop yield to M. micrantha. Nearly 90% of respondents used M. micrantha as a medicinal plant to treat cuts and wounds. The life history of the rust Puccinia spegazzinii de Toni (Pucciniales: Pucciniaceae), originating from Ecuador, and imported into PNG and Fiji in 2008, was studied. P. spegazzinii is a microcyclic and autoecious rust and has a life cycle of 18-22 days. An efficient culturing and field release method was developed. Since 2008, the rust has been released at over 450 sites in 15 provinces in PNG, establishing at nearly 70 sites in four provinces. From some sites, the rust has spread over 7 km in 12 months. In Fiji, the rust has been released at over 80 sites, on four of the main islands, namely Viti Levu, Vanua Levu, Taveuni and Ovalau, and has established at 20 sites on Viti Levu and Vanua Levu. Plant growth studies and field monitoring in PNG showed that P. spegazzinii can significantly reduce the growth and density of M. micrantha and offers great potential for the control of this weed.

Novel Biginelli dihydropyrimidines with potential anticancer activity: A parallel synthesis and CoMSIA study

Novel Biginelli dihydropyrimidines of biological interest were prepared using p-toluene sulphonic acid as an efficient catalyst. All the thirty-two synthesised dihydropyrimidines were evaluated for their in vitro antioxidant activity using DPPH method. Only, compounds 28 and 29 exhibited reasonably good antioxidant activity. Furthermore, the synthesised Biginelli compounds were subjected for their in vitro anticancer activity against MCF-7 human breast cancer cells. The title compounds were tested at the concentration of 10 μg. Compounds exhibited activity ranging from weak to moderate and, from moderate to high in terms of percentage cytotoxicity. Among them, compounds 10 and 11 exhibited significant anticancer activity. In order to elucidate the three-dimensional structure–activity relationships (3D QSAR) towards their anticancer activity, we subjected them for comparative molecular similarity indices analysis (CoMSIA). Illustration regarding their synthesis, analysis, antioxidant activity, anticancer activity and 3D QSAR study is described.

The effect of lycopene on the PI3K/Akt signalling pathway in prostate cancer

Prostate cancer is common in men with very high mortality which is one of leading causes of cancer-related deaths in men. The main treatment approaches for metastasized prostate cancer are androgen deprivation and chemotherapeutic agents. Although there are initial responses to castration, the resistance to the treatment will eventually occur, leading to castration-resistant prostate cancer. The common chemotherapeutic agents for the treatment of prostate cancer are docetaxel and taxane but outcomes of using these drugs have not been satisfactory. Therefore, it is necessary to find better treatment approaches for prostate cancer and to search for compounds that are effective in prostate cancer prevention. Lycopene extracted from tomato and other fruits or plants such as Gac, watermelon, pink grapefruit, pink guava, red carrot and papaya has been shown to be effective on prostate cancer prevention and treatment. The advantage of the application of lycopene for its anti-prostate cancer activity is that lycopene can reach much higher concentration in prostate tissue than other tissues. In this review, the effect of lycopene on PI3K/Akt pathway is summarised, which could be one of major mechanisms for anti-cancer activity of lycopene.

Phytochemicals of papaya and its traditional health and culinary uses – A review

This paper reviews the current research on phytochemical composition and non-Western traditional culinary food preparation and health uses of papaya. Only ripe papaya fruit flesh is normally eaten in Western countries. The orange or red flesh is an excellent source of pro-vitamin A and ascorbic acid. In South-East Asia, both ripe and green fruit are used and additionally leaves are popularly consumed either raw in salad or cooked as a green vegetable. The leaves contain alkaloids as well as quercetin and kaempferol as the main phenolic compounds. In contrast to Western use papaya has a reputation as a medicinal plant in tropical countries where it is grown. Different plant parts such as fruit, leaf, seed, root, bark and flowers have been used as health treatments. These have included use as topical dressings for treating ulcers and dermatitis, gastrointestinal uses such as antihelminthic and antibacterial activity treatments and traditional uses for fertility control. The differences in use for food and health illustrate potential applications and nutritional benefits of the plant which require further research. With better verification the health applications of papaya could be more widely adopted into Western culture.

Evaluation of packaging films to extend storage life of indigenous Australian vegetables and herbs

A study undertaken in Hervey Bay, Queensland, investigated the potential of creating an indigenous agribusiness opportunity based on the cultivation of indigenous Australian vegetables and herbs. Included were warrigal greens (WG) (Tetragonia tetragonioides), a green leafy vegetable and the herb sea celery (SC) (Apium prostratum); both traditional foods of the indigenous population and highly desirable to chefs wishing to add a unique, indigenous flavour to modern dishes. Packaging is important for shelf life extension and minimisation of postharvest losses in horticultural products. The ability of two packaging films to extend WG and SC shelf life was investigated. These were Antimisted Biaxial Oriented Polypropylene packaging film (BOPP) without perforations and Antifog BOPP Film with microperforations. Weight loss, packaging headspace composition, colour changes, sensory differences and microbial loads of packed WG and SC leaves were monitored to determine the impact of film oxygen transmission rate (OTR) and film water vapour transmission (WVT) on stored product quality. WG and SC were harvested, sanitised, packed and stored at 4°C for 16 days. Results indicated that the OTR and WVT rates of the package film significantly (PKLEINERDAN0.05) influenced the package headspace and weight loss, but did not affect product colour, total bacteria, yeast and mould populations during storage. There was no significant difference (PGROTERDAN0.05) in aroma, appearance, texture and flavour for WG and SC during storage. It was therefore concluded that a shelf life of 16 days at 4°C, where acceptable sensory properties were retained, was achievable for WG and SC in both packaging films.