Exploring the Chemical and Biological Potential of Jamun (Syzygium cumini (L.) Skeels) Leaves: A Comprehensive Review

Leaves of jamun collected as agro by-produce during the cultivation of jamun is traditionally used as ayurvedic medicine to treat diabetes, gall bladder stones and other ailments. Most of the beneficial effects of jamun leaves are associated with phytochemicals found in jamun leaves such as gallic acid, tannins, mallic acid, flavonoids, essential oils, jambolin, ellagic acid, jambosine, antimellin and betulinic acid. Jamun possess curative activities like anticancer, antidiabetic, antifertility, anti-inflammatory, antidiarrheal, antimicrobial, antinociceptive, antioxidant, antiradiation, chemotherapeutic, and gastroprotective. The main goal of this review article is to provide information on the nutritional content, phytochemical composition and health promoting properties of jamun leaves. The review of literature based on the phytochemical composition and health promoting benefits of the jamun leaves, suggests that leaves can be used as potential constituent in the formulation of pharmacological drugs. From the review literature it is found that clinical, in-vivo, in-vitro studies are still required to check the health promoting effects of jamun leaves extracts on humans.     

苦荞叶片超氧化物歧化酶的纯化及性质研究

从荞麦生化遗传以及器官衰老机理的研究目的出发,以苦荞叶片为材料,制备出活力较高的铜锌趋氧化物歧化酶。对其理化性质分析表明：该酶在２５９ｎｍ处有一特征吸收峰,分子量约为３１ｋＤ,含有３０８个氨基酸残基,同工酶电泳结果显示三条活性带。     

水稻叶片磷酸烯醇式丙酮酸磷酸酯酶活性及其部分特性

从水稻（Ｏｒｙｚａ ｓａｔｉｖａ）叶片分离出对磷酸烯醇式丙酮酸（ＰＥＰ）较专一的ＰＥＰ磷酸酯酶,其Ｋｍ （ＰＥＰ）为０．４２ ｍ ｍ ｏｌ／Ｌ,作用ｐＨ范围较窄,最适ｐＨ ８．７。它在ｐＨ ６．２—９．５ 范围内及４０℃以下较稳定。Ｐｉ对酶活性影响不大,仅在大于５ ｍ ｍ ｏｌ／Ｌ时表现出轻微的抑制作用。Ｍｇ２＋ 对酶活性具激活作用,在Ｍｇ２＋ 存在条件下,ＣａＣｌ２、ＣｏＣｌ２、ＣｕＳＯ４、ＦｅＳＯ４ 和ＺｎＳＯ４ 均表现抑制作用     

Physiological effects of long-term exposure to low and moderate concentrations of atmospheric NH3 on poplar leaves

Abstract. Poplar shoots ( Populus euramericana L.) obtained from cuttings were exposed for 6 or 8 weeks to NH₃ concentrations of 50 and 100 μgm⁻³ or filtered air in fumigation chambers. After this exposure the rates of NH₃ uptake, transpiration, CO₂ assimilation and respiration of leaves were measured using a leaf chamber. During the long-term exposure also modulated chlorophyll fluorescence measurements were carried out to obtain information about the photosynthetic performance of individual leaves. Both fluorescence and leaf chamber measurements showed a higher photosynthetic activity of leaves exposed to 100 μg NH₃ m⁻³. These leaves showed also a larger leaf conductance and a larger uptake rate of NH₃ than leaves exposed to 50 μg m⁻³ NH₃ or filtered air. The long-term NH₃ exposure did not induce an internal resistance against NH₃ transport in the leaf, nor did it affect the leaf cuticle. So, not only at a short time exposure, but also at a long-term exposure NH₃ uptake into leaves can be calculated from data on the boundary layer and stomatal resistance for H₂O and ambient NH₃-concentration. Furthermore, the NH₃ exposure had no effect on the relation between CO₂-assimilation and stomatal conductance, indicating that NH₃ in concentrations up to 100 μg m⁻³ has no direct effect on stomatal behaviour; for example, by affecting the guard or contiguous cells of the stomata.     

水稻叶片的蔗糖合成酶

糖型叶水稻、小麦、苜蓿叶片中SS的活力≥SPS。中间型叶高粱、菠菜叶片和淀粉型叶烟草、大豆叶片中SS的活力相似文献   

Benzyladenine-induced increase in DNA content in the nucleus of bean leaf cells

Primary leaves of bean plants (Phaseolus vulgaris L.) were treated with benzyladenine (BA) from 7 days after sowing. Nuclei were isolated and the DNA content per nucleus was determined. BA increased the amount of DNA per nucleus of untreated controls by about 50% without nuclear division.     

Nitrate and ammonium accumulation in bermudagrass in relation to nitrogen fertilization and season

Seasonal changes in nitrate and ammonium concentrations were studied inCynodon dactylon (L.) Pers. plants grown for one year in the field in a Mediterranean area. Plants cultivated in a sandy loam soil were fertilized with nitrate-N or ammonium-N at two application rates (250 and 1000 kg N ha⁻¹ year⁻¹) and compared to controls with no added N. Plots were harvested every three weeks from May to November. Shoots were separated into leaves and stems and analyses carried out in both fractions. Nitrogen applications generally led to elevated nitrate concentrations both in leaves and stems at all sampling dates but had little influence on the ammonium concentrations of the tissues. Higher nitrate and ammonium concentrations were found in stems than in leaves, although no levels higher than 0.22% NO ₃ ⁻ −N and 0.10% NH ₄ ⁺ −N were detected in either fraction. Nitrate tended to accumulate mostly in autumn and spring whereas low accumulations were found in summer. Ammonium showed both in leaves and stems a progressive but limited accumulation throughout the period with a peak in October, followed by a strong decrease in November.     

对光呼吸在C3植物中的一种功能的探讨

小麦不离体叶片在无 CO_2气流中,预照3小时2000μmol·m~(-2)·s~(-1)强光后,叶片光合作用受光照抑制的百分率随气流中氧浓度的不同而不同。气流氧浓度在0—10%范围内,随氧浓度升高,光抑制程度减小。在10—50%氧浓度下,叶片光合强度几乎没有不可逆下降。高于50%氧浓度,叶片所受光抑制程度反而随氧浓度提高而加重。预照光强度增加,时间延长,叶片的光抑制程度也增加。在高于2%氧的无 CO_2气流中,叶片在强光下的 CO_2猝发并非都能长时间存在。在8—11%氧浓度下,叶片的 CO_2猝发仅可持续15—30分钟。氧也可使破碎叶绿体免受强光伤害。叶片无论在高氧还是低氧条件下,强光总是只影响叶绿体 PSⅡ活性。     

Cysteine, γ-glutamyl-cysteine and glutathione contents of spinach leaves as affected by darkness and application of excess sulfur. II. Glutathione accumulation in detached leaves exposed to H2S in the absence of light is stimulated by the supply of glycine to the petiole

When illuminated leaf discs and detached leaves of spinach ( Spinacia oleracea L. cv. Estivato) were exposed to 0.4 and 0.25 μl 1^-1 H₂S, respectively, pool sizes of cysteine and glutathione increased. In the dark, apart from these compounds, the level of γ-glutamyl-cysteine also increased. Incubation of leaf discs with 1.0 m M buthionine sulfoximine (BSO) resulted in the accumulation of cysteine only, both in the light and in darkness. When glycine was supplied to the petioles of detached leaves exposed to H₂S in the dark, the accumulation of glutathione was stimulated, while γ-glutamyl-cysteine accumulation was prevented completely. Glycolate and glyoxylate, precursors of glycine in the glycolate pathway, had nearly the same effect as glycine. Although other amino acids were apparently taken up equally well as glycine when supplied to the petiole, they were much less effective, or not effective at all, in restoring glutathione synthesis in the dark. These results provide evidence, that H₂S-induced glutathione accumulation in spinach leaves in the dark is limited by the availability of glycine, giving rise to the accumulation of the metabolic precursor γ-glutamyl-cysteine.     

Resorption efficiency of leaf nutrients in woody plants on Mt. Dongling of Beijing,North China

Aims To explore resorption efficiency of nitrogen (NRE) and phosphorus (PRE) of woody plants in relation to soil nutrient availability, climate and evolutionary history, in North China.Methods We measured concentrations of nitrogen ([N]) and phosphorus ([P]) in both full expanded mature green and senescent leaves of the same individuals for 88 woody species from 10 sites of Mt. Dongling, Beijing, China. We built a phylogenetic tree for all these species and compared NRE and PRE among life forms (trees, shrubs and woody lianas) and between functional groups (N-fixers and non-N-fixers). We then explored patterns of NRE and PRE along gradients of mean annual temperature (MAT), soil inorganic N and available P, and phylogeny using a general linear model.Important findings Mass-based NRE (NRE m) and PRE (PRE m) averaged 57.4 and 61.4%, respectively, with no significant difference among life forms or functional groups. Neither NRE m nor PRE m exhibited significant phylogenetic signals, indicating that NRE m and PRE m were not phylogenetically conserved. NRE m was not related to [N] in green leaves; PRE m was positively correlated with [P] in green leaves; however, this relationship disappeared for different groups. NRE m decreased with [N] in senescent leaves, PRE m decreased with [P] in senescent leaves, for all species combined and for trees and shrubs. NRE m decreased with soil inorganic N for all species and for shrubs; PRE m did not exhibit a significant trend with soil available P for all species or for different plant groups. Neither NRE m nor PRE m was significantly related to MAT for overall species and for species of different groups.