Quantitative characterization of flavonoid compounds in Rooibos tea (Aspalathus linearis) by LC-UV/DAD

Rooibos tea originates from the leaves and stems of the indigenous South African plant Aspalathus linearis. It has gained much attention for clinical purposes in the case of nervous tension, allergies (dermatitis), and various indigestive problems. Recently, antioxidative activity was also attributed to the tea on the basis of its flavonoid content. Therefore, an HPLC method using a C(18) reversed phase column was developed for the assay of 10 flavonoids in aqueous and methanolic infusions. Main compounds determined were the dihydrochalcone aspalthin, rutin, and orientin, and their content was in the range of 1.0 to 1.3 mg/g. The identity of detected flavonoids was confirmed by comparing their retention times and UV and MS spectra with those of corresponding standards. In addition, the MS analysis showed evidence of the presence of other compounds such as nothofagin, dihydroisoorientin, and dihydroorientin.     

Phenolic compounds in hawthorn (Crataegus grayana) fruits and leaves and changes during fruit ripening

Phenolics in the fruits and leaves of Crataegus grayana were identified by HPLC-UV-ESI-MS. The contents of these compounds and their changes during autumn were also analyzed. Epicatechin [1-7 mg/g dry mass (DM) in fruits and 1-10 mg/g DM in leaves), procyanidins B2 (2-4 and 1-8 mg/g DM) and C1 (2-4 and 1-8 mg/g DM), hyperoside (0.5-1 and 2-11 mg/g DM), and a quercetin-pentoside (0.3-0.5 and 2-6 mg/g DM) were the major phenolics in both fruits and leaves. C-Glycosyl flavones were present in leaves (2-5 mg/g DM), whereas only trace levels were found in fruits. Ideain and 5-O-caffeoylquinic acid were found only in fruits. An additional 11 phenolics were identified/tentatively identified. Total phenolic contents reached highest levels by the end of August in fruits and by the end of September in leaves. The compositional profiles of phenolics in fruits and leaves of C. grayana were different from those of other Crataegus species.     

Arsenic uptake,distribution, and accumulation in tomato plants: Effect of arsenite on plant growth and yield

The response of tomato (Lycopersicum esculentum Mill, cultivar Marmande) plants to different levels of arsenic (As) in nutrient solution was investigated—the processes of uptake, distribution and accumulation of As, and the effect of arsenite on yield and plant growth (plant height, diameter of stem, stem and root length, fresh and dry weight of root, stems, leaves, and fruit). The experiment was performed at three levels of As: 2, 5 and 10 mg/L [added as sodium arsenite (NaAsO₂)] in a nutrient solution, together with the corresponding control plants. Arsenic uptake depended on the As concentration in solution and As content in the roots increased as the time of treatment increased. The most important finding was the high toxicity of arsenite to roots. The concentration in stems, leaves, and fruit was correlated with the As level in the nutrient solution. Although the As level of 10 mg/L damaged the root membranes, resulting in a significant decrease in the upward transport of As. Arsenic exposure resulted in a drastic decrease in plant growth parameters (e.g., maximum decrease of 76.8% in leaf fresh weight) and in tomato fruit yield (maximum reduction of 79.6%). However, it is important to note that the As concentration in the fruits was not toxic or harmful for human consumption.     

水稻对~(14)CO_3~(2-)的吸收和积累动态

用同位素示踪技术研究水稻对14CO32-的吸收和积累动态,及其在水稻田中的行为特性。结果表明:通过水稻根系和浸于水中的茎杆下部吸收的14CO32-离子会向上部组织输送并形成积累趋势;在上部组织中,叶和茎杆上部的14C比活度随时间呈逐渐上升的趋势,而穗中的比活度于14d达最大值(271.9Bq/g)后又呈下降趋势;茎杆下部由于直接浸于水中,表现出对14CO32-离子的快速吸收、吸附,此后随时间呈下降趋势,根部表现出上升过程迟后于茎杆下部,其14C比活度也低于茎杆下部。上部组织(穗、叶和茎杆上部)中14C的百分含量随时间上升,而下部组织(茎杆下部和根)则相反,至试验后期(21~35d),其百分含量基本持平(约各占50%),14C从下部组织向上部组织输送的特征非常明显。     

Growth and Fruit Chemical Characteristics of Blackberry (Rubus Fruticosus) Cultivated with Vermicompost,Glomus Mosseae and Phosphate Rock

Abstract

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe (AMF). Plant growth parameters, total phenol compounds and total flavonoids were evaluated on leaves. Anthocyanin contents, soluble solids (SS), pH, titratable acidity (TA) and SS/TA ratio was evaluated in blackberries fruits. Blackberry plants were obtained from cuttings from field plants, which were distributed in soil according to a randomized complete block design with three repetitions. Treatments were vermicompost (10?g plant^?1), phosphate rock (1?g plant^?1), Glomus mosseae (AMF), (1?g plant^?1), PR + AMF, V + PR, V +AMF, V + PR+ AMF and control without any amended. Plant height and stem diameter were measured five months after treatments, while total phenols and total flavonoids in leaves were evaluated eight months later. Anthocyanins, SS, pH, and TA were determined in blackberry fruits ten months after. Plant height was not statistically affected (p≤0.05), although total phenol compounds were higher (21.1?mg g^?1 dry plant) in the V+PR+AMF treatment, whereas the V + AMF treatment produced more dry plant total flavonoids (1.4?mg g^?1), compared with control plants. Blackberries produced with the vermicompost treatment had more anthocyanins (9.54?mg g^?1) than control plants. Soluble solids, pH and titratable acidity were not statistically (p≤0.05) affected by any treatment.     

Growth and Nutrient Absorption of Cape Gooseberry (Physalis Peruviana L.) in Soilless Culture

Cape gooseberry (Physalis peruviana L.) is a solanaceous plant. The growth and time-course of nutrient accumulation of the plant and its partitioning between roots, stems, leaves, and fruits were examined. The study was conducted analyzing two nutrient solutions in soilless culture under greenhouse conditions during two consecutive seasons. The macronutrient contents were analyzed. On average, the yield was 8.9 t·ha^?1. Growth of the plant until 90 d after transplanting obeys an exponential function of time and the relative growth rate for this period was determined. Nitrogen (N) was the element that showed the highest concentration, corresponding to leaves (4.67%), followed by potassium (K) in stems (4.46%). The highest accumulations of N, phosphorous (P), calcium (Ca), and magnesium (Mg) were found in leaves and of K in the stems. Potassium showed the highest nutrient accumulation (29 g·plant^?1) and the highest specific uptake rate.     

Unfermented rooibos tea: quantitative characterization of flavonoids by HPLC-UV and determination of the total antioxidant activity

Unfermented rooibos originates from the leaves and the stems of the indigenous South African plant, Aspalathus linearis, and it has been reported to have a higher content of flavonoids compared to that of fermented rooibos. The HPLC/UV method developed in our laboratory for the analysis of the fermented rooibos was applied to the quantitative characterization of the major flavonoids present in the unfermented rooibos. Main compounds determined were aspalathin (49.92 +/- 0.80 mg/g), isoorientin (3.57 +/- 0.18 mg/g), orientin (2.336 +/- 0. 049 mg/g), and rutin (1.69 +/- 0.14 mg/g), followed in order by isovitexin, vitexin, isoquercitrin and hyperoside, quercetin, luteolin and chrysoeryol. The identity of detected flavonoids was confirmed by comparing their retention times and UV spectra with those of corresponding standards. The total antioxidant activity (TAA) of the tea infusions was measured by the ABTS*+ radical cation decolorization assay. The TAA of unfermented rooibos (0.8 Trolox meq/g) resulted 2-fold higher than that of the fermented rooibos. When compared with different water infusions of Camellia sinensis (green and black tea), this TAA value was about 50% lower.     

芭蕉芋干物质及矿质营养元素累积与分配特征研究

以3 个芭蕉芋栽培品种为试材,研究了芭蕉芋发棵结芋期和子芋完熟期生物量的构成特点及各器官矿质元素含量、 积累和分配规律,以期为芭蕉芋科学管理和合理施肥提供依据。结果表明,发棵结芋期,芭蕉芋干物质量为54.99~62.21g/plant,叶片是干物质主要的分配器官; 子芋完熟期,芭蕉芋的干物质量是发棵结芋期的 4 倍多,根茎为干物质的主要分配器官。发棵结芋期,3 个芭蕉芋品种平均每株累积吸收N 497.4mg~598.8mg、 P 128.7mg~223.1mg、 K 2021.2.mg~2450.3mg、 Ca 496.0 mg~577.3 mg、 Mg 526.7 mg~804.5 mg,氮以叶片中含量最高,磷、 钾和镁以茎中含量最高,根系内钙含量最高; 子芋完熟期,芭蕉芋平均每株累积N 1116.2~1210.8mg、 P 852.6~907.5mg、 K 4528.9~5055.2 mg、 Ca 919.2~991.7mg、 Mg 888.2~1369.0 mg,氮以叶片含量最高,钾含量以根系最高,磷含量以茎、 叶中最高,根茎内镁含量高。生育期内构建相同生物量,Xingyu-1需要的 K、 Ca 和 Mg 比其他 2个品种多,N和P与其他2个品种相当,但Xingyu-1 的根茎干物质分配率高,生产相同质量的干根茎,Xingyu-1 需要的N、 P、 K 低于其他 2 个品种。     

Some effects of fly ash (from coal burning) on bush bean plants grown in solution culture

Abstract

Bush bean plants (Phaseolus vulgaris L. C. V. Improved Tendergreen) were grown for 14 days in 3700‐ml solution cultures with varying application rates of fly ash from a coal burning plant in California. Plants were also grown in a solution culture experiment in the presence of tiie chelating agent DTPA (diethylene triamine pentaacetic acid) and also in solutions acidified with HCl. The latter treatments were to determine if metals in the fly ash could be made more available to plants. The higher levels of fly ash (5 to 10 g/3700 ml) resulted in increased Ca, B, Si, Sr, and Ba in leaves, stems, and roots. No plants, however, appeared to have an excess of trace metals. In another experiment DTPA and HCl amendments failed to increase greatly the availability of trace metals from the fly ash in solution culture except for Zn. In this experiment the fly ash was the sole source of Ca and plants were deficient in Ca because insufficient fly ash was added. The fly ash resulted in increased Zn, Ca, Fe, Mn, B, Al, Si, Ti, Mo, Li, Sr, Ba in leaves, stems, and roots and increased V, Co, and Ni in roots. There was 3 to 4 μg/g Sn and 0.6 μg/g Be in the roots of plants grown with fly ash. In another experiment, fly ash supplied all the Ca necessary for plant growth without decreased yields resulting from any trace metal.     

再生水灌溉不同滴头布置方式下PPCPs在土壤和番茄中的累积

随着药品和个人护理品(Pharmaceuticals and Personal Care Products,PPCPs)生产和使用量的增加,PPCPs及其代谢产物在再生水中的检出种类、检出量不断增多,再生水灌溉可影响PPCPs在土壤-作物(蔬菜)系统中的分布及累积,但其规律及驱动机制尚不明确。为探明再生水滴灌条件下滴头布置方式对PPCPs在土壤-作物(蔬菜)系统累积的影响,该研究采用盆栽试验比较2种滴头布置方式(在番茄根部、在两番茄中间)对土壤剖面及番茄各器官中PPCPs累积量的影响,并进一步分析PPCPs在土壤-作物(蔬菜)系统累积的驱动机制。结果表明,再生水灌溉条件下不同滴头布置方式造成了PPCPs在土壤、作物(蔬菜)中累积规律的差异性,滴头布置在两番茄中间处理较其他处理而言增加了0～5cm土层吉非罗齐累积量(P0.05),降低了番茄叶部卡马西平和根部吉非罗齐的累积量(P0.05),较滴头布置在番茄根部处理降低了番茄叶部吉非罗齐和根部三氯生的累积量(P0.05);不同再生水灌溉方式通过影响土壤微环境指标导致了土壤中PPCPs分布规律的差异性,滴头布置在植株中间处理较其他处理增加了0～5 cm土层pH值,导致该土层下吉非罗齐的累积量高于其他处理(P0.05)。研究可为基于新兴污染物PPCPs防控的再生水农业安全利用提供理论依据。     

外源铁对不同品种番茄光合特性、品质及镉积累的影响

【目的】在人工模拟镉污染土壤条件下,讨论了叶面喷施Fe对番茄Cd积累及化学形态的影响,旨在为镉污染土壤上番茄的安全生产提供理论依据。【方法】采用土培试验研究了在重金属Cd(10 mg/kg)污染条件下,叶面喷施不同浓度Fe(0、200和400μmol/L,Fe SO4·7H2O)对2个番茄品种(‘4641’和‘渝粉109’)生长、光合特性、品质及果实Cd形态和Cd积累量的影响。【结果】叶面喷施Fe提高了番茄的根、茎、叶、果实干重及植株总干重,增幅分别为20.4%~48.6%、13.3%~56.0%、16.0%~63.1%、9.8%~16.5%和21.6%~40.3%,随着喷施Fe浓度的增加,番茄各部位干质量及总干质量呈先增加后降低的趋势,比较两个番茄品种,‘4641’耐Cd性更强,而‘渝粉109’对Fe的反应更为敏感;随着喷施Fe浓度的增加,2个番茄品种的叶片净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)呈先增加后降低趋势,在Fe 200μmol/L时最大,品种‘4641’的Pn、Gs和Tr较对照分别增加了8%、11%和2.9%,而‘渝粉109’较对照分别增加了28.7%、15.5%和18.8%。而喷Fe处理却降低了番茄叶片胞间CO2浓度(Ci),比较2个供试番茄品种,‘4641’光合作用和蒸腾作用强度均高于‘渝粉109’;喷Fe提高了2种番茄果实的硝酸盐含量以及渝粉‘109’还原糖含量,降低了‘渝粉109’果实氨基酸含量,喷施高浓度Fe(400μmol/L)能提高2种番茄果实Vc含量,与对照相比,‘4641’和‘渝粉109’果实硝酸盐增加的幅度分别为18.1%~22.2%、2.3%~22.0%,Vc较对照分别增加了8.2%和13.2%;番茄果实中Cd的主要存在形态为残渣态,其次为盐酸提取态,去离子水提取态和乙醇提取态所占比例较小,残渣态Cd(FR)和盐酸提取态Cd(FHCl)为活性偏低形态Cd,占Cd提取总量的70.8%,去离子水提取态(FW)和乙醇提取态(FE)为活性较高形态Cd,仅占Cd提取总量的11.8%,有效地抑制了Cd的毒害作用。叶面喷施Fe降低了番茄果实各形态镉含量;番茄中Cd主要积累在叶和茎中,而果实和根的积累量较少;喷Fe降低了番茄叶、根、茎、果实的Cd含量,降低幅度分别为7.1%~21.9%、35.6%~50.4%、13.0%~37.0%和2.8%~8.2%,但喷施高浓度Fe(400μmol/L)相比低Fe(200μmol/L)时的番茄各部位Cd含量有所增加,无论是非否喷施Fe,叶、茎、果实中的Cd积累量以及总Cd积累量总是以‘4641’‘渝粉109’,表明在Cd污染土壤上种植‘4641’较‘渝粉109’风险更大。【结论】叶面喷施适量Fe能够促进番茄的光合作用和蒸腾作用,提高了番茄各部位的干重,降低了Cd对番茄的毒害效应,同时减少了番茄各部位Cd含量。     

Profiling glucosinolates, flavonoids, alkaloids, and other secondary metabolites in tissues of Azima tetracantha L. (Salvadoraceae)

Azima tetracantha L. (needle bush; bee sting bush; Salvadoraceae) is used as a food and for various herbal medicines in Africa, India, and Madagascar, but there is very little information on the secondary metabolites in this species. High concentrations of N-methoxy-3-indolylmethyl-glucosinolate, a common glucosinolate of Brassica crops such as Brussels sprouts and broccoli, were found in the roots and seeds of A. tetracantha. Lower concentrations were detected in the stems and young leaves. The roots also contained another indole glucosinolate that was provisionally identified, from MS data and comparison with indole glucosinolate standards, as N-hydroxy-3-indolymethyl-glucosinolate. The roots, stems, and leaves contained neoascorbigen (the condensation product of N-methoxy-indole-3-carbinol and ascorbic acid). The seeds of A. tetracantha contained a complex mixture of 26 flavonoids predominantly as glycosides and acyl-glycosides, with traces of aglycones. The core aglycones of these flavonoids were identified as quercetin, isorhamnetin (3'-O-methylquercetin), rhamnetin (7-O-methylquercetin), and rhamnazin (7, 3'-di-O-methylquercetin). No flavonoids or anthocyanins were detected in other tissues, and procyanidins were undetectable. The dimeric piperidine alkaloids azimine, azcarpine, and carpaine were found in all tissues of A. tetracantha.     

Effects of Antitranspirant Spray and Potassium: Calcium: Magnesium Ratio on Photosynthesis,Nutrient and Water Uptake,Growth, and Yield of Sweet Pepper

Sweet pepper plants (Capsicum annuum L.) were cultivated hydroponically under different nutrient cation ratios at both high potassium (K)/calcium (Ca) (12:2) or magnesium (Mg)/Ca (4:2) ratios, compared with half strength Hoagland's solution (K:Ca:Mg; 3.5:2:0.5). Additionally, antitranspirant (Pinolene) was sprayed every fortnight to the aerial part of the plant at 1% (v/v). The antitranspirant (AT) did not affect dry weight accumulation in the leaves, stems, roots, total plant leaf area, or leaf dry weight percentage. Net carbon dioxide (CO₂) assimilation was not impaired by the AT but the water uptake was reduced significantly independent of the nutrient solution used. The AT did not affect the cation uptake but high Mg significantly reduced Ca concentration in leaves, stems, and fruits, whilst high K had an effect only in old leaves and fruits. The AT reduced fructose and glucose concentration in the leaves but no effect was found in the fruits. Fruit yield was not affected by AT, but it was increased when plants were grown with high Mg/Ca. The percentage of blossom-end rot was reduced with the AT, whilst it was increased with the solutions having high K/Ca or high Mg/Ca. The AT significantly reduced fruit firmness in high Mg/Ca and control solution but no effect was found for fruit color, shape index, total soluble solids, or pericarp thickness.     

Lithium toxicity in plants

Abstract

The toxicity of Li to three plant species was studied to determine if there were interactions with other elements and to determine if a chelating agent modified Li toxicity. Bush beans (Phaseolus vulgarls L. C.V. Improved Tendergreen), grown in solution culture, were sensitive to 0.5 X10^‐3Li which resulted in 10 μg/g in leaves, 48 in stems, and 24 in roots. Higher concentrations of Li produced marked reductions in plant yield accompanied by increased Li concentrations in leaf, stem, and root tissues. For most treatments, root concentrations of Li were lower than those in shoots, but those in stems were higher than those in leaves. Higher levels of Li decreased Zn in leaves, increased Ca in stems, and generally increased Fe and Mn in all plant tissues. Ethylenediamine tetraacetic acid (EDTA) resulted in slightly increased Ii levels in leaves, stems, and roots. Bush bean plants were injured slightly with 25 μg Li/g of Yolo loam soil applied as LiCl; 50 μg Li/g soil caused more severe injury. Leaf concentrations of about 200 μg Li/g resulted in significant yield reduction and around 600 μg//g of leaves resulted in severe toxicity. There were some interactions of Li with other elements which resulted in an increase of them in both leaf and stem tissues. Barley plants (Hordeum vulgare L. C.V. Atlas 57) were severely stunted when grown with 500 and 1000 μg Li/g soil as Li oxalate. Increasing the soil pH even further with lime and decreasing it with S had no influence on the toxicity. Shoot concentrations of Li ranged from 800 to over 2000 in the various treatments resulting in severe disruption of the Ca and K balance. Leaf concentrations of Li were higher than those for stems in cotton (Gossypium hirsutum L. C.V. Acala 442). Cotton was tolerant of a leaf concentration of 587 μg Li/g. High levels of Li increased concentrations of several elements in cotton leaves and in stems. Cotton leaves accumulated more Li than did bush beans.     

5个蓖麻品种对土壤中镉富集的差异

为了评价能源作物蓖麻对污染农田中重金属镉(Cd)的富集修复能力,本研究以5个蓖麻品种为试验材料,通过大田试验对比了不同蓖麻品种在Cd污染农田中的生长情况、对Cd的富集和转运能力以及对Cd污染土壤的修复能力。结果表明,5个蓖麻品种在Cd污染农田中生长良好,其中滇蓖2号的株高、茎粗及单株产量显著高于其他品种,分别为440.78 cm、5.04 cm以及338.85 g。5个蓖麻品种根、茎、叶及果实的Cd含量、Cd积累量和富集系数均存在显著差异,其中经作蓖麻1号根、茎和果实的Cd含量最高,分别为1.40、1.14和0.33 mg·kg^-1。污染修复能力方面,滇蓖2号Cd的积累量达3.38 mg/株,提取率为5.34%,显著高于其他品种。经作蓖麻1号尽管富集能力最强,但由于其生物量最小,其Cd积累量及年提取效率均最低。综上可知,蓖麻对土壤中重金属Cd的富集能力较强,可用于修复云南个旧地区的Cd污染土壤,且种植滇蓖2号可以获得较好的修复效果。本研究结果为云南Cd污染土壤治理提供了理论基础和参考依据。     

粉蕉矿质元素吸收积累与分配特征

为探明粉蕉矿质营养元素的累积分配特征,以主栽品种广粉1号为试材,采用彻底刨根、分解取样的方法,研究了干物质的构成特点、各器官矿质元素含量和累积分配特性。结果表明:粉蕉植株总干质量为17.6 kg/plant,其中叶片占16.4%,假茎占32.8%,球茎占9.6%,果实占37.3%,果轴占1.1%,根占2.8%。平均每株累积吸收N 167.0g、P 19.3g、K 521.7g、Ca 118.3g、Mg 54.7g、S 16.6g、Fe 6650.5mg、Mn 16142.9mg、Cu 152.3mg、Zn 607.7mg、B 212.2mg、Mo 4.2mg,养分比例N:P:K:Ca:Mg:S为1:0.12:3.12:0.71:0.33:0.10。其中N、P、Ca和S主要向叶片、假茎和果实分配,K和Mg主要向假茎分配,Fe主要向叶片、根和球茎分配,Cu主要向假茎和果实分配,Zn和Mo主要向叶片、假茎和球茎分配,B和Mn主要向假茎和叶片分配。为获得60t/hm2的高产,粉蕉需要吸收N 385.6kg、P 44.6kg、K 1205.1kg、Ca 273.3kg、Mg 126.6kg、S 38.3kg、Fe 15.4kg、Mn 37.3kg、Cu 352.0g、Zn 1403.8g、B 490.1g、Mo 9.6g。     

Vegetables collected in the cultivated Andean area of northern Chile: total and inorganic arsenic contents in raw vegetables.

High levels of arsenic are found in the soil and water of the Second Region in Chile as a result of natural causes. Total and inorganic arsenic contents were analyzed in the edible part of 16 agricultural products (roots, stems, leaves, inflorescences, and fruits) grown in this area. The total arsenic contents varied in the range 0.008-0.604 microg g(-1) of wet weight (ww), below the maximum level allowed by Chilean legislation (1 microg(-1) of ww). Inorganic arsenic contents (range = 0.008-0.613 microg(-1) of ww) represented between 28 and 114% of total arsenic. The concentrations of total and inorganic arsenic found in edible roots and leaves were higher than those found in fruit. The highest concentrations were found in a sample of spinach. High quantities of this vegetable would have to be consumed (250 g/day) to reach the Provisional Tolerable Weekly Intake for inorganic arsenic. The vegetable group may make a considerable contribution to the total intake of inorganic arsenic.     

Bioactive polyphenols in leaves, stems, and berries of Saskatoon (Amelanchier alnifolia Nutt.) cultivars

The Saskatoon berry is currently cultivated in many parts of the world for its suitability for various food products and due to its high content of nutrients and polyphenols. To determine the phytochemical profile of a Saskatoon plant, polyphenols from leaves, stems, and berries were screened from four cultivars grown in Finland using HPLC-DAD and HPLC-ESI/MS. The phenolic composition and concentrations varied among plant parts and cultivars. The main berry components were cyanidin-based anthocyanins (63% of the phenols), quercetin-derived flavonol glycosides, and hydroxycinnamic acids. The total anthocyanin content varied between 258.7 and 517.9 mg/100 fresh weight among cultivars. Protocatechuic acid was found for the first time in Saskatoon berries. The leaves consisted of quercetin- and kaempferol-derived glycosides (41% of the phenols), hydroxycinnamic acids (36%), catechins, and some neolignans. Quercetin 3-galactoside and 3-glucoside, (-)-epicatechin, and chlorogenic acid were the main phenolics in the leaves of all cultivars. The stem components were flavanone and flavonol glycosides (55% of the phenols), catechins (38%), and hydroxybenzoic acids. Concentrations of the main compound, eriodictyol 7-glucoside, varied among cultivars from 3.3 to 6.5 mg/g of stem dry weight. Very high proanthocyanidin contents were found in stems and leaves (10-14% of dry biomass), whereas berries contained a low amount of proanthocyanidins (3% of dry biomass). The findings reveal that leaves and stems of Saskatoon cultivars possess high amounts of various phenolic compounds that may offer new functional raw materials for a wide range of food and health products.     

Flavonoid (myricetin, quercetin, kaempferol, luteolin, and apigenin) content of edible tropical plants.

Studies were conducted on the flavonoids (myricetin, quercetin, kaempferol, luteolin, and apigenin) contents of 62 edible tropical plants. The highest total flavonoids content was in onion leaves (1497.5 mg/kg quercetin, 391.0 mg/kg luteolin, and 832.0 mg/kg kaempferol), followed by Semambu leaves (2041.0 mg/kg), bird chili (1663.0 mg/kg), black tea (1491.0 mg/kg), papaya shoots (1264.0 mg/kg), and guava (1128.5 mg/kg). The major flavonoid in these plant extracts is quercetin, followed by myricetin and kaempferol. Luteolin could be detected only in broccoli (74.5 mg/kg dry weight), green chili (33.0 mg/kg), bird chili (1035.0 mg/kg), onion leaves (391.0 mg/kg), belimbi fruit (202.0 mg/kg), belimbi leaves (464.5 mg/kg), French bean (11.0 mg/kg), carrot (37.5 mg/kg), white radish (9.0 mg/kg), local celery (80.5 mg/kg), limau purut leaves (30.5 mg/kg), and dried asam gelugur (107.5 mg/kg). Apigenin was found only in Chinese cabbage (187.0 mg/kg), bell pepper (272.0 mg/kg), garlic (217.0 mg/kg), belimbi fruit (458.0 mg/kg), French peas (176.0 mg/kg), snake gourd (42.4 mg/kg), guava (579.0 mg/kg), wolfberry leaves (547.0 mg/kg), local celery (338.5 mg/kg), daun turi (39.5 mg/kg), and kadok (34.5 mg/kg). In vegetables, quercetin glycosides predominate, but glycosides of kaempferol, luteolin, and apigenin are also present. Fruits contain almost exclusively quercetin glycosides, whereas kaempferol and myricetin glycosides are found only in trace quantities.     

Effects of chromium on the nutrient element content and morphology of tomato

An hydroponic experiment was conducted to study the effects of chromium (Cr³⁺) on the distribution of nitrogen (N), phosphorus (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), and Cr in the plant, and the growth and yield of a tomato plant. Three Cr treatments were established (0, 50, and 100 mg Cr/L in a nutrient solution). In general, the nutrient element concentration in stems and branches was significantly affected by the Cr treatments. Chromium accumulated preferentially in the roots and low transport was detected to the aerial parts. Growth was diminished due to Cr presence in the nutrient solution. Total yield was not affected, however the number of fruits was diminished and the mean fresh weight of fuit increased with each increment of Cr in the nutrient solution. Chromium was not detected in the edible part (fruit) of the plant.