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1.
The enzymatic hydrolysis of cycasin with cycad-emulsin, prepared from the seeds of Cycas revoluta, is described. As the complete degradation products we obtained about one mole each of formaldehyde, nitrogen gas, and methanol per mole of cycasin, in addition to glucose, the sugar component. These products are the same as those found in the acid hydrolysis of cycasin which has been reported previously. Therefore, it is concluded that the aglycone of cycasin can not be liberated intact as a single component, but decomposes into those smaller molecules as above even by means of the enzymatic hydrolysis.  相似文献   

2.
Yagi F 《Phytochemistry》2004,65(24):3243-3247
Azoxyglycoside contents in leaves of 32 cycad species belonging to 10 cycad genera and the seeds of 4 Encephalartos species were analyzed by HPLC with a YMC-PA03 amide column. Azoxyglycosides were detected in mature leaves of 14 cycad species including 2 Bowenia, 2 Lepidozamia, 1 Microcycas, and 1 Stangeria species, but not in mature leaves of 18 other cycad species; 2 of 3 Ceratozamia, 1 of 3 Cycas, 3 of 3 Dioon, 10 of 11 Encephalartos, 1 of 3 Macrozamia and 1 of 3 Zamia species analyzed. The ratios of beta-glycosidase activity toward cycasin and macrozamin in extracts from the leaves of 9 species belonging to 9 genera were measured. The hydrolysis of cycasin was higher in the leaf extracts of Cycas revoluta, Bowenia spectabilis, Stangeria eriopus and Ceratozamia mexicana, whereas in Lepidozamia hopei, the hydrolysis levels of cycasin and macrozamin were similar. On the other hand, activity toward macrozamin was higher in Dioon edule, Encephalartos villosus, Macrozamia miquelii and Zamia fischeri. The hydrolytic activities in most species were estimated to be sufficient for the release of methylazoxymethanol in leaves analogous to the cyanogenesis of cyanogenic plants. Therefore, hydrolysis of azoxyglycosides by endogenous glycosidase in leaves seems to occur by accidental injury of leaves. However, in M. miquelii leaf extract, hydrolytic activity toward macrozamin was high and the activity toward cycasin was very low, though only cycasin was found in the leaves of this species.  相似文献   

3.
During times of pre-European Australia, indigenous people utilized methods of food procurement that resulted in toxic phytochemicals from plants entering their waterholes. This paper focuses on three of these plants, namely the leaves of Acacia colei and Duboisia hopwoodii, which were used by hunters to poison water holes to stun fish or a drinking animal, and the seeds of Castanospermum australe, which were eaten following the leaching of toxins into a running stream. If consumed by humans, the main toxins from these plants—saponins/sesquiterpenes, nicotine/nornicotine, and australine/castanospermine—are fatal. However, it is undetermined whether populations of Cyanobacteria also can be affected. During this study, the previously mentioned plants were administered to populations of the species Anabaena circinalis, Microcystis aeruginosa, and Nodularia spumigena, while mimicking the traditional applications of these plants as closely as possible. Results varied with treatments and species; however, cell chlorosis manifested in nearly all treatments, concomitantly with thylakoid membrane disorganization. Cell dormancy typically manifested, along with destruction of populations at higher treatments. The results indicated that populations of Cyanobacteria could have been destroyed or inhibited by indigenous people during traditional applications of these plants. Findings presented herein indicate a more sophisticated and complex traditional Australian resource management scheme than is currently understood, contributing to the growing awareness of the plight of earlier indigenous Australians. The reintroduction of traditional water management techniques may have potential as a suitable small-scale water resource management strategy.  相似文献   

4.
《Mutation Research Letters》1995,346(3):145-149
Cycasin, methylazoxymethanol-β-glucoside, is a naturally occurring carcinogenic compound. The genotoxicity of cycasin was assayed in the Drosophila wing spot test. Cycasin induced small single and large single spots on feeding at 10 μmol/g medium. The presence of these spots indicates that cycasin is genotoxic in Drosophila melanogaster. Microorganisms which showed β-glucosidase activity for cleaving cycasin to toxic aglycon were isolated from gut flora of the Drosophila larvae. Consequently, the Drosophila wing spot test would be useful for mutagenicity screening of other naturally occurring glucosides.  相似文献   

5.
Carbohydrate food sources have emerged as a critical factor limiting occupation of rainforests by hunter—gatherer peoples globally. In the wet tropics bioregion of northeastern Australia, Kuku–Yalanji aboriginal people occupied the rainforests through a hunter–gatherer subsistence economy prior to European occupation. Collaborative environmental research between a researcher at the James Cook University and Kuku–Yalanji people has established that their fire management protected carbohydrate resources in the fire-sensitive rainforests and their margins, and ensured ongoing access to the critical dry season carbohydrate resource, Cycas media, growing in patches of fire-prone open forest on each clan estate. Carbohydrate resources in the wet season were obtained predominantly from seeds of rainforest tree nuts, a high proportion of which are wet tropics endemic species. Several of the genera utilized by aboriginal people in the wet tropics bioregion also occur in the rainforests of eastern Cape York Peninsula, where they were not utilized as foods. It is hypothesized that use of rainforest seeds for carbohydrate is a cultural adaptation that occurred in the wet tropics bioregion, stimulated by the unique availability of the substantial number of large-seeded rainforest trees that are wet tropics endemics. The implications of these data for concepts about the impact of aboriginal fires on Australian rainforests are considered. Aboriginal fires imposed a fine patterning on the vegetation at the local scale, with little effect on the vegetation at the regional scale, which is determined by environmental factors.  相似文献   

6.
Summary Aboriginal people perceive land and water as equal components of country, and hold distinct perspectives on water relating to identity and attachment to place, environmental knowledge, resource security, and the exercise of custodial responsibilities to manage interrelated parts of customary estates. This paper documents Aboriginal perspectives from certain areas in northern Australia, defined as the region of tropical savannas stretching from Townsville to Broome, and offers a number of suggestions for improving current knowledge of Aboriginal values and Aboriginal participation rates in water and catchment management. The paper highlights the cultural significance of rivers and water in selected northern regions, and provides a preliminary outline of research and management priorities as determined by key north Australian Aboriginal land management organizations. Priorities include developing the capacity for collaborative aquatic resource management, conservation of traditional ecological knowledge, riparian resource inventories and threat assessment, as well as improved Aboriginal participation in catchment management and water policy. Although there is a strong north Australian focus to this paper, the issues raised are relevant to water and natural resource management policy throughout Australia.  相似文献   

7.
The traditional, current and potential uses ofMyoporum species are documented. Historically, this genus was valued by the Australian Aboriginal people for cultural purposes and as a food plant of minor importance. Medicinal remedies were also acquired from this shrub.Myoporum species were utilised by Aboriginal people in both coastal and Central Australia and throughout the Pacific region. These hardy shrubs are characterised by their drought, fire, frost and grazing tolerances. They have horticultural potential and are good sources of selected phytochemicals.  相似文献   

8.
NJ Sadgrove 《EcoHealth》2012,9(3):315-327
Interest in preserving the cultural knowledge of Aboriginal Australians continues to rise. Various studies have erupted which aim to redefine knowledge that was once lost or obscured in writing and hitherto ignored. Recognising and acknowledging the traditional Aboriginal knowledge of the Australian environment helps to strengthen Aboriginal identity and gives credibility to the rising paradigm of ecotechnology in historic pre-European Australia. This review aims to establish knowledge of a traditional awareness of factors leading towards eutrophication in water resource management. Journals from pioneering explorers were examined for evidence of cyanobacterial blooms and examples of Aboriginal water resource management practices that aimed at avoiding health threats from poor water quality. Some cultural practices, focused on water resource management, are discussed with brief mentioned of the Waugal. It is concluded that in some cases the incorporation of scientific laws into mythology is a form of conceptual modelling compatible with science if examined carefully.  相似文献   

9.
Quantitative paper chromatography of cycasin is described, where the cycasin and sugars separated on the paper are eluted out and determined, according to the colorimetric micro analysis of sugars by Plumel. The contents of cycasin and free sugars contained in both premature and matured cycad seeds determined by this method are presented.  相似文献   

10.
α-Amino-β-methylaminopropionic acid, previously isolated from seeds of Cycas circinalis, has now been identified either free or bound in all th  相似文献   

11.
Fire has been a critical component of Aboriginal culture and natural resource management in Australia for millennia. Aboriginal fire management in Northern Australia is widespread and, in some more remote areas, has continued relatively undisrupted despite widespread changes in tenure and land use. For the Wik people of Western Cape York, there has been a continued connection to their culture and traditional lands. Recently, Wik traditional owners have formed a ranger program which has secured funding to manage contemporary land management issues. This includes the landscape‐scale management of fire for biodiversity conservation and greenhouse gas abatement. Because the work is being conducted by Aboriginal people, with consent from traditional owners and on their traditional lands, there is an assumption that the activities are compatible with historical traditional land management and cultural practices. In this study, we use participatory action research to compare contemporary fire management with the current understanding of traditional Aboriginal fire management to assess objectively the compatibility of these two paradigms. We do this by combining the experience and understanding of traditional owners with anthropological and ecological perspectives. We find that contemporary fire management is applied across traditional cultural boundaries using methods such as aerial incendiaries. Financial incentives and contractual obligations associated with fire management are externally driven or include modern considerations such as the protection of infrastructure. In contrast, traditional fire management was the prerogative of traditional owners and was applied at fine scales for specific outcomes. Fire management was governed by rules that determined how people moved across the landscape and how resources were partitioned and shared. Supporting the implementation of Aboriginal burning alongside current fire management practices could lead to significant community engagement in such activities and is likely to have much better biodiversity and social outcomes.  相似文献   

12.
13.
F. M. Strong 《CMAJ》1966,94(12):568-573
Toxic components of natural foodstuffs are discussed, with special reference to lathyrogens, pressor amines, azoxyglycosides, and labile sulfur compounds. The osteolathyrogen, γ-glutamyl-β-aminopropionitrile, in sweet pea (Lathyrus odoratus) seeds induces skeletal deformities and aortic rupture, probably by interfering with normal maturation of collagen fibres. Neurolathyrism in man may be caused by β-N-oxalyl-L-α,β-diaminopropionic acid, a neurotoxin recently identified in Lathyrus sativus seeds. Histamine, tyramine, noradrenaline, serotonin and other pressor amines occur in fruits and fermented foods such as bananas, pineapples, cheese and wine. Consumption of such foods by patients taking monoamine oxidase-inhibiting drugs (e.g. tranylcypromine) may produce serious hypertensive crises. Cycad nuts, widely used as human food in tropical and subtropical areas, contain a potent carcinogen, methyl azoxymethanol, which is more or less removed prior to use by leaching in water. Consumption of plants of the onion, cabbage and cress families introduces into the body such toxic chemicals as benzyl cyanide, goitrin and thiocyanates. The lachrymatory substance in onions is propenyl sulfenic acid.  相似文献   

14.
Indigenous fire knowledge offers significant benefits for ecosystem management and human livelihoods, but is threatened worldwide because of disruption of customary practices. In Australia, the historical prevalence and characteristics of Aboriginal burning are intensely debated, including arguments that Aboriginal burning was frequent across the continent. Frequent burning is supported by contemporary Aboriginal knowledge and practice in some regions, but in southern Australia evidence is typically limited to historical and ecological records. Towards characterizing Aboriginal fire regimes in southern Australia, we collaborated with Ngadju people from the globally significant Great Western Woodlands in south‐western Australia to document their fire knowledge. We used workshops, site visits, interviews and occupation mapping to aid knowledge sharing. Consistent with the established significance of Aboriginal fire in Australia, planned fires were important in Ngadju daily life and land management. However, Ngadju use of fire was characterized by its selectivity rather than its ubiquity. Specifically, Ngadju described only highly targeted planned burning across extensive eucalypt woodlands and sandplain shrublands. By contrast, frequent planned burning was described for resource‐rich landscape elements of more restricted extent (granite outcrop vegetation, grasslands and coastal scrub). Overall, Ngadju fires are likely to have resulted in subtle but purposeful direct effects on the vegetation and biota. However the extent to which they collectively constrained large, intense wildfires remains unclear. Ngadju demonstrated a predictive knowledge of the ecological consequences of burning, including attention to fine‐scale needs of target organisms, and application of diverse fire regimes. These are consistent with the recently proposed concept that Aboriginal burning was guided by ‘templates’ targeting different resources, although diverse regimes predominantly reflect edaphically driven vegetation patterns rather than template‐driven use of fire to create resource diversity. We conclude that Ngadju fire knowledge fills an important gap in understanding Aboriginal fire regimes in southern Australia, highlighting a novel balance between frequent and constrained use of fire.  相似文献   

15.

Background

Little is known about the use of bush medicine and traditional healing among Aboriginal Australians for their treatment of cancer and the meanings attached to it. A qualitative study that explored Aboriginal Australians' perspectives and experiences of cancer and cancer services in Western Australia provided an opportunity to analyse the contemporary meanings attached and use of bush medicine by Aboriginal people with cancer in Western Australia

Methods

Data collection occurred in Perth, both rural and remote areas and included individual in-depth interviews, observations and field notes. Of the thirty-seven interviews with Aboriginal cancer patients, family members of people who died from cancer and some Aboriginal health care providers, 11 participants whose responses included substantial mention on the issue of bush medicine and traditional healing were selected for the analysis for this paper.

Results

The study findings have shown that as part of their healing some Aboriginal Australians use traditional medicine for treating their cancer. Such healing processes and medicines were preferred by some because it helped reconnect them with their heritage, land, culture and the spirits of their ancestors, bringing peace of mind during their illness. Spiritual beliefs and holistic health approaches and practices play an important role in the treatment choices for some patients.

Conclusions

Service providers need to acknowledge and understand the existence of Aboriginal knowledge (epistemology) and accept that traditional healing can be an important addition to an Aboriginal person's healing complementing Western medical treatment regimes. Allowing and supporting traditional approaches to treatment reflects a commitment by modern medical services to adopting an Aboriginal-friendly approach that is not only culturally appropriate but assists with the cultural security of the service.  相似文献   

16.
Methyl methanesulphonate (MMS), applied on barley seeds, inhibits the seed respiration and thein vitro activity of cytochrome-oxidase and catalase, whereas doubles the activity of total dehydrogenases and has no influence on the activity of peroxidase. Storage of MMS-treated seeds for 10 days at 30% seed water content, thus under conditions favouring the recovery from the MMS-induced toxic and genetic effects, resulted in an enhancement of the cytochrome oxidase and catalase activity, which reached or exceeded the activity of the control. The activity of peroxidase, although increasing during storage, did not attain the value of the control and the activity of total dehydrogenases remained two times higher as compared to the control.  相似文献   

17.
18.
Cycasin, the toxic glycoside of cycad plants, interfered with seed germination and seedling growth of Gramineae, Crucifereae and Leguminosae. The shoots and roots of seedlings showed wilting, chlorosis and necrosis. Rice plants were most sensitive and soybean plants rather tolerant.

Respiration and α-amylase activity were markedly low in the rice seedlings treated with cycasin. Both cycasin and its aglycone, methylazoxymethanol, did not inhibit the activity of α-amylase, but did suppress the formation of α-amylase in rice endosperms. Exogenous gibberellin considerably reversed the inhibition of germination and growth, and the suppression of α-amylase formation caused by these toxins.  相似文献   

19.
Richard E Petit 《ZooKeys》2012,(255):103-109
The monotreme genus Zaglossus, the largest egg-laying mammal, comprises several endangered taxa today known only from New Guinea. Zaglossus is considered to be extinct in Australia, where its apparent occurrence (in addition to the large echidna genus Megalibgwilia) is recorded by Pleistocene fossil remains, as well as from convincing representations in Aboriginal rock art from Arnhem Land (Northern Territory). Here we report on the existence and history of a well documented but previously overlooked museum specimen (skin and skull) of the Western Long-Beaked Echidna (Zaglossus bruijnii) collected by John T. Tunney at Mount Anderson in the West Kimberley region of northern Western Australia in 1901, now deposited in the Natural History Museum, London. Possible accounts from living memory of Zaglossus are provided by Aboriginal inhabitants from Kununurra in the East Kimberley. We conclude that, like Tachyglossus, Zaglossus is part of the modern fauna of the Kimberley region of Western Australia, where it apparently survived as a rare element into the twentieth century, and may still survive.  相似文献   

20.
Excised embryonic axes and whole seeds of Phaseolus lunatus L. were previously shown to be injured if exposed to low (5°-15°) temperature during the initial stages of imbibition. Present data show that this chilling injury during imbibition of liquid water can be prevented if axes are first allowed to absorb water vapor. The increase of initial water content to 20% increases growth even of unchilled axes, and reduces leaching of 264 mμ absorbing compounds. Protection resulting from increased water content is at first independent of the temperature at which water vapor was absorbed. However, longer exposure of high moisture axes to low temperature results in typical chilling injury. The response to initial seed moisture is repeatedly reversible with changes in water content. Because the same response occurs in intact seeds, it may be possible both to protect them against low temperature injury and to increase vigor by increasing seed water-content prior to planting.  相似文献   

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