Herbicidal activity of flavonoids of mango leaves against Parthenium hysterophorus L

This study was undertaken to investigate the herbicidal activity of mango (Mangifera indica L.) leaves against parthenium weed (Parthenium hysterophorus L.). The aqueous leaf extract at 15% concentration (on fresh weight basis) significantly reduced germination, shoot length and the shoot and root biomasses of parthenium seedlings. In a leaf residue incorporation pot trial, 2% residue incorporation treatment significantly suppressed the root and shoot biomasses of parthenium, while a 5% residue treatment completely stopped the growth of the weed. Five flavonoids, namely (-)-epicatechin-3-O-β-glucopyranoside (1), 5-hydroxy-3-(4-hydroxyphenyl)pyrano[3,2-g]chromene-4(8H)-one (2), 6-(p-hydroxybenzyl)taxifolin-7-O-β-D-glucoside (tricuspid) (3), quercetin-3-O-α-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (4) and (-)-epicatechin(2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H chromene-3,5,7-triol (5) were isolated from mango leaves. In a laboratory bioassay, 50 ppm solution of compounds 3 and 4 caused yellowing of the parthenium seedlings. A 250 ppm solution of compound 4 also significantly reduced germination and the root and shoot lengths of parthenium seedlings. This study concludes that compound 4 exhibits herbicidal activity against parthenium weed.     

Phytochemical screening,total phenolic content and phytotoxic activity of corn (Zea mays) extracts against some indicator species

Allelopathic effects of corn (Zea mays) extracts was studied, against seed germination and seedling growth of Phalaris minor, Helianthus annuus, Triticumaestivum, Sorghum halepense, Z. mays. Bioassay results showed that aqueous extracts of corn root and shoot, markedly affected seed germination, and other parameters compared with related controls. Preliminary phytochemical screening revealed the presence of various phytochemicals such as tannins, phlobatannins, flavonoids, terpenoids and alkaloids in both roots and shoot aqueous extracts. However, saponins were only present in the shoot aqueous extract, while in shoot ethanol extracts, only terpenoids and alkaloids were detected. Additionally, total polyphenolic (TPC) content in aqueous extracts of corn root and shoot, plus ethanol extracts of corn shoot were determined using an Ultraviolet–visible spectroscopy. Results revealed TPC content of the corn shoot aqueous extract showed the highest yield, compared to other extracts. These findings suggest that phytochemicals present in Z. mays extracts may contribute to allelopathy effect.     

Application of HR-MAS NMR spectroscopy for studying chemotype variations of Withania somnifera (L.) Dunal

Withania somnifera (L.) Dunal (Solanaceae), commonly known as Ashwagandha, is one of the most valued Indian medicinal plants with a number of pharmaceutical and nutraceutical applications. Metabolic profiling has been performed by HR-MAS NMR spectroscopy on fresh leaf and root tissue specimens from four chemotypes of W. somnifera. The HR-MAS NMR spectroscopy of lyophilized defatted leaf tissue specimens clearly distinguishes resonances of medicinally important secondary metabolites (withaferin A and withanone) and its distinctive quantitative variability among the chemotypes. A total of 41 metabolites were identified from both the leaf and root tissues of the chemotypes. The presence of methanol in leaf and root tissues of W. somnifera was detected by HR-MAS NMR spectroscopy. Multivariate principal component analysis (PCA) on HR-MAS (1) H NMR spectra of leaves revealed clear variations in primary metabolites among the chemotypes. The results of the present study demonstrated an efficient method, which can be utilized for metabolite profiling of primary and secondary metabolites in medicinally important plants.     

Biological screening of some Turkish medicinal plant extracts for antimicrobial and toxicity activities

Screening of antibacterial activity and toxicity of 22 aqueous plant extracts from 17 Turkish plants was conducted. Antibacterial activity was performed with six bacteria including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Staphylococcus epidermidis. Extracts of Tussilago farfara leaves, Helichyrsum plicatum flowers, Solanum dulcamara aerial parts and Urtica dioica leaves gave the best inhibitory activity against S. pyogenes, S. aureus and S. epidermidis. Of the 22 plant extracts, 20 extracts displayed toxicity (LC50 was <1000 mg L(-1)) in the brine shrimp bioassay. For radish seed bioassay, two different determinations (root length and seed germination) were performed with a comparison between two concentrations (50,000 mg L(-1) and 10,000 mg L(-1)). At low concentration (10,000 mg L(-1)), S. dulcamara aerial parts and Primula vulgaris leaf extracts were observed to inhibit the root length more than the other plant extracts. Also, the most inhibitive plant extract for seed germination was obtained with S. dulcamara aerial parts.     

Herbicidal activity of culture filtrates of Trichoderma spp. against two problematic weeds of wheat

The herbicidal potential of culture filtrates of four Trichoderma spp., namely Trichoderma harzianum Rifai, Trichoderma pseudokoningii Rifai, Trichoderma reesei Simmons and Trichoderma viride Pers., was evaluated against two problematic weeds of wheat, Phalaris minor L. and Rumex dentatus L. In laboratory bioassays, generally, metabolites of all four Trichoderma species significantly reduced various root and shoot growth parameters of the two target weed species. The original concentrations of the culture filtrates of all Trichoderma spp., except T. harzianum, significantly reduced various parameters of root and shoot growth of wheat seedlings. In a foliar spray bioassay, the culture filtrates of all four Trichoderma spp. significantly diminished root and shoot biomass of R. dentatus. The effect of these filtrates on the shoot growth of P. minor and wheat was not significant. Culture filtrates of the four Trichoderma species were successively extracted with butanol, n-hexane, chloroform and ethyl acetate. In detached leaf injection bioassays, n-hexane fractions (3 mg mL(-1)) of T. pseudokoningii, T. reesei and T. viride, and ethyl acetate fractions of T. horzianum and T. pseudokoningii were found to be toxic against R. dentatus. This study concludes that the culture filtrates of Trichoderma species have herbicidal potential in the control of R. dentatus.     

Withanolide A biogeneration in in vitro shoot cultures of ashwagandha (Withania somnifera DUNAL), a main medicinal plant in Ayurveda

Multiple shoot cultures of two experimental lines of Withania somnifera plants (RS-Selection-1 and RS-Selection-2) were established using nodal segments as explants. The hormonal combinations of benzyl adenine and kinetin not only influenced their morphogenetic response but also differentially modulated the level of biogeneration of withanolide A in the in vitro shoots of the two lines. Interestingly, withanolide-A, that was hardly detectable in the aerial parts of field-grown Withania somnifera (explant source), accumulated considerably in the in vitro shoot cultures of the plant. The productivity of withanolide A in the cultures varied considerably (ca. 10-fold, 0.014 to 0.14 mg per gram fresh weight) with the change in the hormone composition of the culture media as well as genotype used as source of the explant. The shoot culture of RS-Selection-1 raised at 1.00 ppm of BAP and 0.50 ppm of kinetin displayed the highest concentration of withanolide A in the green shoots of 0.238 g per 100 g dry weight tissue. This was a more analytical concentration keeping in view the isolation yields so far reported from the dried roots of the field-grown plant (ca. 0.015 g per 100 g dry weight), even if isolation losses are considered during purification. The enhanced de novo biogenesis of withanolide A in shoot cultures was corroborated with radiolabel incorporation studies using [2-(14)C] acetate as a precursor. Production of withaferin A was also found in the in vitro shoot cultures. As this compound is a predominant withanolide of native shoots as well and has been already reported to be accumulated in in vitro shoot cultures, its biogeneration observed in these shoot cultures is not discussed in detail.     

Chlorobiphenyl (PCB) composition of extracts of subsurface soil, superficial dust and air from a contaminated landfill

Samples of 3 matrices (air, superficial dust and subsurface soil) from an aged PCB-containing landfill were extracted and the extracts refined for bioassay. Acetone: hexane extraction was modestly selected for non-planar compounds. Coplanar PCBs and PCDFs were enriched about 2-fold in the subsequent benzene:methylene chloride extracts of the soil. Extract refinement with Florisil slurry and alumina column chromatography did not appreciably change the composition of the extracts. CB 28 (2,4,4′-triCB) dominated in all extracts. The congener composition of soil and air were surprisingly similar, being enriched in tri- and tetraCBs while dust retained higher proportions of congeners with 4 and 5 chlorines. It is postulated that anaerobic dechlorination in the moist subsurface soil depleted the higher chlorinated congeners; more volatile congeners escaped into the atmosphere while moderately chlorinated congeners were trapped in the superficial dust and debris. The refined extracts represent distinct compositions of environmental PCB mixtures suitable for bioassay.     

Biochemical alternation and silicon accumulation in groundnut (Arachis hypogaea L.) in response to root and foliar application of two sources of silicon

Abstract

Silica deposits in leaves of groundnut ranged from 3.23 to 6.16% and 2.61 to 6.52% when sodium meta silicate was applied as foliar spray at the rate of 0.5, 1.0, 2.0, 3.5 and 5.0%, and soil application at the rate of 5.0, 7.5, 10.0, 15 and 20% and 4.44 to 11.94% and 3.57 to 9.33% when calcium silicate was applied through leaves and soil at the same doses, respectively in contrast to 2.0% in plants without silica fertilizer applications. Similarly, polyphenol oxidase (PPO) activity was highest (43.26 units) in plant system, in case of foliar spray of calcium silicate at the rate of 5.0% and 33.80 units with reference to foliar spray of meta silicate at the rate of 5.0% whereas it was only 19.10 units in untreated check. Among the two sources of silica fertilizers tested, foliar spray of calcium silicate at 5.0% was effective in facilitating the maximum deposition of silica content apart from increasing the activities of PPO in groundnut leaves.     

Separation, identification, and quantification of selected withanolides in plant extracts of Withania somnifera by HPLC-UV(DAD)--positive ion electrospray ionisation-mass spectrometry

This paper describes a method for separation, identification, and quantification of selected withanolides in Withania somnifera plant extracts by HPLC-UV(DAD)-Mass Spectrometry (HPLC-MS). Withaferin-A (WS-3), 12-deoxywithastramonolide (WS-12DS), Withanolide A (WS-1), and Withanone (WS-2) were used as external standards. The compounds were isolated from Withania somnifera by repeated column chromatography of the root extract and their identity was established by 1H- and 13C-NMR and mass spectral data. The compounds were chromatographed on a Merck (250 x 4.6 mm ID, 5 microm) column and analyzed by Electrospray Ionization on a mass spectrometer in Selected Ion Mode (SIM). For quantification, [M + Na]+ ions were monitored. Linear calibration curves were obtained in the concentration range of 1.50 microg/mL to 6.5 microg/mL. The method was applied successfully to the detection and quantification of the said withanolides in a number of samples.     

Chlorobiphenyl (PCB) composition of extracts of subsurface soil, superficial dust and air from a contaminated landfill

Samples of 3 matrices (air, superficial dust and subsurface soil) from an aged PCB-containing landfill were extracted and the extracts refined for bioassay. Acetone:hexane extraction was modestly selected for non-planar compounds. Coplanar PCBs and PCDFs were enriched about 2-fold in the subsequent benzene:methylene chloride extracts of the soil. Extract refinement with Florisil slurry and alumina column chromatography did not appreciably change the composition of the extracts. CB 28 (2,4,4′-triCB) dominated in all extracts. The congener composition of soil and air were surprisingly similar, being enriched in tri- and tetraCBs while dust retained higher proportions of congeners with 4 and 5 chlorines. It is postulated that anaerobic dechlorination in the moist subsurface soil depleted the higher chlorinated congeners; more volatile congeners escaped into the atmosphere while moderately chlorinated congeners were trapped in the superficial dust and debris. The refined extracts represent distinct compositions of environmental PCB mixtures suitable for bioassay. Received: 21 November 1995 / Revised: 9 April 1996 / Accepted: 14 April 1996     

Herbicidal activity and bioactive components of Brucea javanica (L.) Merr. residue

There are many nutrients and active substances in the residue of traditional Chinese medicine, which can be processed into organic fertilizer and returned to the field to improve the soil fertility. In this study, we found that Brucea javanica (L.) Merr. residue has herbicidal activity and can be used for weed control in the field, this prompted us to investigate the active constituents in it. The herbicidal activities of extracts of B. javanica residue were evaluated by conducting bioassays against gramineous weed, Eleusine indica (L.) Gaertn. and broad-leaved weed, Bidens pilosa L., respectively. It confirmed that ethyl acetate and n-butanol extracts possessed potent biological activities on seed germination and seedling growth of E. indica at 5 mg/mL. This prompted us to investigate the active constituents in the seeds residue. By the activity-guided fractionation, eight known compounds were isolated, which were bruceines D?F (1–3), pityriacitrin (4), 4-(9H-β-carbolin-1-yl)-4-oxobut-2-enoic acid methyl ester (5), protocatechuic acid (6), vanillic acid (7) and carisphthalate (8). Then, three quassinoids (1–3) were evaluated for their potential herbicidal effects in bioassay. Results showed that bruceines D?F have potential herbicidal activity against the test weeds. In the range of experimental concentration, bruceine D had obvious herbicidal effect on the two tested weeds. At the concentration of 31.25 μg/mL, bruceine D could completely inhibit the root growth of E. indica; at the concentration of 125 μg/mL, bruceine D can inhibit the seed germination and shoot elongation of E. indica and the shoot growth of B. pilosa, with the inhibition reached 100%. In addition, at the same concentration (250 μg/mL), bruceines D?F could completely affected shoot elongation of B. pilosa. These results showed that B. javanica residue is a potential source of botanical herbicide development, which has great agricultural economic value, at the same time, the reuse of B. javanica residue realizes the transformation of waste into treasure, rational utilization of resources and sustainable development.     

High Frequency Shoots Regeneration for Mass Multiplication of Phyllanthus fraternus Webster—An Important Antiviral and Hepatoprotective Plant

An efficient, rapid, and highly reproducible regeneration protocol was successfully developed for Phyllanthus fraternus from the field-derived mature nodal segments. The explants induced multiple shoots on cytokinin containing medium. The highest frequency (99 %) and maximum number of shoots (19.75) were induced on Murashige and Skoog’s (MS) medium supplemented with 2.22 μM 6-benzylaminopurine after 3–4 weeks of culture initiation. The elongated shoots were rooted on MS medium supplemented with indol-3-butyric acid (IBA) or α-naphthalene acetic acid. Pulse treatment of microshoots promoted significant increase in the percentage of rooting and number of root regeneration per shoot. The highest rooting (100 %) and maximum number of roots (8.75) per shoot was obtained when shoots were dipped in IBA solution (0.98 mM) for 5 min and further subcultured on MS basal medium. Plantlets were successfully acclimatized and established in soil. Regenerated plants were grown normally in the field without showing any morphological variations. This cost-effective protocol will help the mass multiplication of P. fraternus for commercial propagation and high biomass production of this valuable medicinal plant.     

Withania somnifera root extracts induce skin darkening in wall lizard melanophores via stimulation of cholinergic receptors

The effects of the root extract of Withania somnifera and its active ingredient Withaferin A on the isolated melanophores of the wall lizard H. flaviviridis were studied in order to establish the mechanism of skin darkening at the cellular level. Significant skin darkening activity of the extract of W. somnifera and Withaferin A was observed on the isolated melanophores of the wall lizard. The melanin dispersal effects leading to the darkening of the skin were antagonised by atropine and hyoscine, and were also found to be highly potentiated by neostigmine. These findings suggest that the extract of W. somnifera, as well as its active principle, mimic the action of acetylcholine in melanin dispersion, thus leading to skin darkening via stimulation of cholinergic receptors of muscarinic nature within the melanophores of the wall lizard.     

In-vitro antagonistic characteristics of crude aqueous and methanolic extracts of Garcinia kola (Heckel) seeds against some Vibrio bacteria

The methanolic and aqueous extracts of Garcinia kola seeds were screened for their anti-Vibrio activities against 50 Vibrio isolates obtained from wastewater final effluents in the Eastern Cape Province, South Africa. The crude extracts at 10 mg/mL exhibited appreciable inhibitory activities against most of the test Vibrio isolates, with zones of inhibition ranging from 10-19 mm for methanol extract and 8-15 mm for the aqueous extracts. The minimum inhibitory concentrations (MIC) of the methanol extract varied from 0.313 to 2.5 mg/mL while that for the aqueous extract was 10 mg/mL for all the susceptible Vibrio isolates. Rate of kill assay of the methanolic extracts against three selected Vibrio species showed bacteriostatic activities against all of them achieving 58% and 60% (Vibrio vulnificus AL042); 68% and 69% (Vibrio parahaemolyticus AL049); and 70% and 78% (Vibrio fluvialis AL040) killing of the test bacteria at 3× and 4 ×MIC values, respectively, after 2 h exposure time. We conclude that Garcinia kola seeds hold promise as a potential source of therapeutic compounds of relevance in Vibrio infections management.     

HPTLC Detection and Identification of Heroin (Diacetylmorphine) in Forensic Samples. Part III

JPC – Journal of Planar Chromatography – Modern TLC - Anew spray reagent, a 1% (w/v) aqueous solution of ferric chloride and a 1% (w/v) acidified alcoholic solution of...     

Herbicidal activity of curvuiinic acid isolated from Nimbya alternantherae

A phytotoxic compound, identified as 2-(2-acetyl-3,5-dihydroxyphenyl) acetic acid (curvulinic acid), was isolated from liquid cultures of the phytopathogenic fungus Nimbya alternantherae. The activity of curvulinic acid on seed germination and seedling growth of Capsella bursa-pastoris was evaluated. Percentage seed germination of C. bursa-pastoris was decreased with increasing concentrations of curvulinic acid. The compound had stronger inhibitory effects on root length than shoot length. At a concentration of 600 microg x mL(-1), curvulinic acid caused 73.5% and 66.7% growth inhibition on roots and shoots with IC50 values of 204.7 and 281.1 microg x mL(-1), respectively. The finding of curvulinic acid in N. alternantherae and its herbicidal activity are reported here for the first time.     

Quantitative estimation of parthenolide in Tanacetum parthenium (L.) Schultz-Bip. cultivated in Egypt

Parthenolide, a germacranolide-type sesquiterpene lactone, was estimated in Tanacetum parthenium (L.) cultivated in Egypt by using colorimetric, planar chromatographic, and high-performance liquid chromatographic (HPLC) methods. Parthenolide levels in the open-field herb and aseptically germinated shoots were also compared by using the HPLC method. Parthenolide was produced and estimated for the first time in the callus culture of the plant. In addition, 2 Egyptian market preparations were analyzed for their parthenolide content by using the HPLC method. The relative standard deviations were 0.093, 0.095, and 0.098% (n = 5, 5, and 7, respectively), and the corresponding recoveries were 98.2, 98.9, and 99.4% for the colorimetric, planar chromatographic, and HPLC determinations, respectively.     

Shoot organogenesis from root-derived callus of Rhinacanthus nasutus (L.) Kurz. and assessment of clonal fidelity of micropropagted plants using RAPD analysis

An efficient regeneration system was established for an ethnomedicinal shrub Rhinacanthus nasutus from root-derived callus organogenesis. The root segments were cultured on MS medium supplemented with various concentrations of Kn (1.0–4.0 μM) alone or in combination with IBA (0.2–0.6 μM) or 2, 4-D (0.5–1.5 μM). The optimum frequency (94 %) of callus induction was recorded on MS medium supplemented with 3.0 μM Kn and 0.4 μM IBA. For shoot regeneration from callus, MS medium supplemented with different concentrations (1.0–7.0 μM) of BA or TDZ alone or in combination with NAA (0.2–1.0 μm) was employed. The highest frequency of shoot regeneration (91 %) and mean number of shoots (28.3) were observed on MS medium supplemented with 5.0 μM BA and 0.7 μM NAA. The shoots were excised and cultured on MS medium with 4.0 μM IBA produced 3.4 roots per shoot in 88 % cultures. Of the 65 plants transferred to soil 54 survived (83 %). The plants were transferred to field after successful hardening. RAPD analysis of the regenerated plants showed high similarity with the mother plant.     

Phytochemical profile and biological activities of Deverra tortuosa (Desf.)DC.: a desert aromatic shrub widespread in Northern Region of Saudi Arabia

The present study describes the chemical composition of the essential oil of different plant parts of Devrra tortuosa; in vivo and in vitro biological activities of plant extract and essential oils. Apiol was found to be the major component of the oil (between 65.73% and 74.41%). The best antioxidant activities were observed for the oil of flowers (IC50 = 175 μg/ml). The samples of stems and roots exhibit lower antioxidant activity (IC50 = 201 μg/ml and 182 μg/ml, respectively). The values of IC50 showed that the extracts of methanol exhibit the highest antioxidants activities (IC50 = 64.8 102 μg/ml). EOs showed excellent antifungal activity against yeasts with low azole susceptibilities (i.e. Malassezia spp. and Candida krusei). The MIC values of oils varied between 2.85 mg/mL and 27 mg/mL. The obtained results also showed that the plant extracts inhibited the germination and the shoot and root growth of Triticum æstivum seedlings.     

Insights on Molecular Characteristics of Hydrochars by 13C-NMR and Off-Line TMAH-GC/MS and Assessment of Their Potential Use as Plant Growth Promoters

Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through ¹³C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response.