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1.
  1. Terrapins are integral to many freshwater ecosystems, yet are imperilled at a global scale. In Sri Lanka, terrapins are understudied; thus, much of their natural history and distribution status remain unknown. Such paucity of studies impedes conservation.
  2. In this study, 79 freshwater habitats located outside the protected area network of south‐western Sri Lanka were surveyed to document current population densities and habitat use of two terrapin species: Indian black terrapin (Melanochelys trijuga thermalis ) and flap‐shelled terrapin (Lissemys ceylonensis ). Local inhabitants were interviewed to assess human threats towards terrapins.
  3. Both species were recorded in low densities: 1–2 individuals ha?1. Indian black terrapin was found in half of the surveyed sites while flap‐shelled terrapin occurred in one‐third of the surveyed sites. Highly urbanized river basins had the lowest densities for both species while rural basins supported higher numbers. Basking was the predominant behaviour of both species and large woody debris and boulders were preferred as basking substrates, together with sparse‐canopy aquatic habitats with intact marshlands.
  4. Overharvesting for meat was a major threat for terrapins. Most local inhabitants were unaware of legislation on terrapin conservation and the ecological importance of terrapins. Human threats such as pollution, modification of aquatic and wetland habitats, and loss of riparian forests were frequently observed in surveyed sites. Terrapin populations outside the protected area are at risk as evidenced by lower population densities and a multitude of human threats.
  5. A landscape‐scale ecosystem‐based conservation approach is recommended for Sri Lanka's terrapins with incorporation of lands with different management regimes (privately owned, municipality managed) into the protected area network. Current environmental legislation should be revised to support buffer zone delineation for aquatic habitats, wetland restoration, and landscape‐scale connectivity.
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2.
The gymnemic acid contents in various organs of Gymnema sylvestre were investigated by High Performance Liquid Chromatography (HPLC) method. The results shows that the content of gymnemic acid in various organs, obviously different, was 54.29, 31.66, 28.82, 27.67, 25.39, 20.56 and 1.31 mg·g−1 DW in shoot tips, flowers, nodes, leaves, internodes, roots and seeds, respectively. The highest gymnemic acid content (54.29 mg·g−1 DW) was found in shoot tip, 1.96 fold higher than that in leaves (27.67 mg·g−1 DW). Maximum quantity of gymnemic acid (35.39 mg·g−1 DW) was observed in the young leaves, which was 1.52 times higher than that in old leaves (23.07 mg·g−1 DW). The content of gymnemic acid in young, middle and old internodes was 26.47, 25.77 and 23.94 mg·g−1 DW, respectively, all lower than that in leaves (27.67 mg·g−1 DW), whereas the content of gymnemic acid in young, middle and old nodes was 27.96, 28.81 and 29.66 mg·g−1 DW, respectively, all higher than that in leaves. The study provides the scientific evidences for the rational development and utilization of Gymnema sylvestre resources, since over exploitation of natural stands has caused depletion of these plants in nature. Foundation project: This work was supported by University Grants Commission, New Delhi (No. 33-88/2007 (SR))  相似文献   
3.
Helicteres isora root extracts were studied for antinociceptive activity on acetic acid-induced writhing test in mice, at a dose of 250 mg/kg. Petroleum ether, chloroform and aqueous ethanol extracts have shown significant activity.  相似文献   
4.
Vanilla extract was prepared by extraction of cured vanilla beans with aqueous ethyl alcohol (60%). The extract was profiled by HPLC, wherein major compounds, viz., vanillic acid, 4-hydroxybenzyl alcohol, 4-hydroxy-3-methoxybenzyl alcohol, 4-hydroxybenzaldehyde and vanillin, could be identified and separated. Extract and pure standard compounds were screened for antioxidant activity using beta-carotene-linoleate and DPPH in vitro model systems. At a concentration of 200 ppm, the extract showed 26% and 43% of antioxidant activity by beta-carotene-linoleate and DPPH methods, respectively, in comparison to corresponding values of 93% and 92% for BHA. Interestingly, 4-hydroxy-3-methoxybenzyl alcohol and 4-hydroxybenzyl alcohol exhibited antioxidant activity of 65% and 45% by beta-carotene-linoleate method and 90% and 50% by DPPH methods, respectively. In contrast, pure vanillin exhibited much lower antioxidant activity. The present study points toward the potential use of vanilla extract components as antioxidants for food preservation and in health supplements as nutraceuticals.  相似文献   
5.
6.
Zinc (Zn) and nickel (Ni) accumulation in the seedlings of two pigeonpea [Cajanus cajan (L.) Millspaugh] cultivars were studied under different concentrations of Zn and Ni supplied. Significant differences in the seedling growth were observed between the two cultivars of pigeonpea as well as between Zn and Ni treatments. The Zn and Ni treatments decreased dry weights and relative growth indices of the roots and shoots. The Zn and Ni accumulation was greater in the roots of cv. LRG30 than cv. ICPL87. The amount of metal ions allocated to the shoots was more in cv. ICPL87 than in cv. LRG30. The conspicuous compartmentation of Zn and Ni in the roots of the seedlings and the differential responses of the two cultivars of pigeonpea to these heavy metals indicated that cv. LRG30 possesses better root compartmentation of Zn and Ni and therefore resulted in relatively better growth than cv. ICPL87.  相似文献   
7.
利用高效液相色谱法(HPLC)测定匙羹藤(Gymmnema sylvestre)不同器官的匙羹藤酸含量.结果表明:不同器官的匙羹藤酸含量明显小同,在顶芽、花、节点、叶、节间、根和种子的匙羹藤酸含量分别为,54.29、31.66、28.82、27.67、25.39、20.56和1.31 mg·g-1 DW.在幼叶中,匙羹藤酸(35.39 mg·-1DW)含量最高,比老叶的匙羹藤酸(23.07 mg·g DW含量高1.52倍.幼年,中年和老年节间的匙羹藤酸含量分别为26.47、25.77和23.94 mg·g-1DW,均低于叶的匙羹藤酸含量,而幼嫩,中部节和老节点的匙羹藤酸含量分别为27.96、28.81和29.66 mg·g-1 DW,均高于叶的匙羹藤酸含量.因为过度开采引起了这些植物在自然界的损耗,本研究为匙羹藤资源的发展和利用提供了科学依据.  相似文献   
8.
9.
The ethanol, ethyl acetate and butanol extracts of Helicteres isora root showed significant oral hypoglycemic activity on glucose loaded rats at a dose of 250 mg/kg. The butanol extract showed maximum antihyperglycemic activity and effect being comparable to that of glibenclamide.  相似文献   
10.
Antihyperglycemic activity of Caralluma attenuata   总被引:1,自引:0,他引:1  
Extracts of Caralluma attenuata are screened for their antihyperglycemic activity. Ethanol, chloroform and butanol extracts were tested on glucose loaded and alloxan-induced diabetic rats. In both tests, the butanol extract, at the oral dose of 250 mg/kg, has shown statistically significant and considerable antihyperglycemic activity.  相似文献   
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