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1.
Determination of colchicine content in Colchicum hierosolymitanum and Colchicum tunicatum under cultivation 总被引:1,自引:0,他引:1
Corms of Colchicum hierosolymitanum and Colchicum tunicatum were collected, identified and planted under field condition. We report here and for the first time the presence of colchicine in an appreciable amount in both species. The effect of different NPK fertilizer levels on colchicine content of the two Colchicum species at different growth stages were evaluated by HPLC. Results indicated that increasing NPK fertilizer levels significantly improve colchicine content in different plant parts and stages. The highest colchicine content observed in corms was at maturity stage 0.766 mg/g and 0.688 mg/g dry weight with C. hierosolimitanum and C. tunicatum, respectively. 相似文献
2.
Isolation, characterization, and biological evaluation of active components of Colchicum stevenii Kunth (Colchicaceae) are described. Colchicum stevenii is an unexplored Jordanian specie with toxic reputation. Directed by brine shrimp lethality test (BST), methanolic extraction, liquid-liquid partition, preparative TLC, and semi-preparative HPLC, it resulted in the isolation of six cytotoxic compounds. The compounds, reported for the first time from this specie, are: (-)-colchicine (1), 2-demethyl-(-)-colchicine (2), (-)-cornigerine (3), beta-lumicolchicine (4), (-)-isoandrocymbine (5) and (-)-O-methylandrocymbine (6). A new, in-house developed, acidic-based reverse-phase gradient semi-preparative HPLC method for the separation of colchisides is presented here. Structural elucidation was based on spectroscopic techniques principally; 1H-NMR and low resolution EIMS. Based on BST results, reported as LC50 values in microg mL(-1) (ppm) with 95% confidence intervals, (-)-colchicine (2.5 ppm) and (-)-cornigerine (2.7 ppm) were the most potent. 相似文献
3.
Mashhour Alali Bani-Ata 《代数通讯》2013,41(7):2439-2443
The aim of this article is to investigate all semifields A of order q 4 where q is a power of 2, having the properties that A contains GF(q 2) in its left nucleus and admits a four-group E ? Z 2 × Z 2 of automorphisms of A acting freely on A. 相似文献
4.
Khaled Tawfik Alali Dr. Jingyuan Liu Dr. Rongrong Chen Dr. Qi Liu Dr. Hongsen Zhang Jundong Li Jindi Hou Prof. Rumin Li Prof. Jun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(51):11892-11902
Semiconductor metal oxides (SMO)-based gas-sensing materials suffer from insufficient detection of a specific target gas. Reliable selectivity, high sensitivity, and rapid response–recovery times under various working conditions are the main requirements for optimal gas sensors. Chemical warfare agents (CWA) such as sarin are fatal inhibitors of acetylcholinesterase in the nerve system. So, sensing materials with high sensitivity and selectivity toward CWA are urgently needed. Herein, micro-nano octahedral Co3O4 functionalized with hexafluoroisopropanol (HFIP) were deposited on a layer of reduced graphene oxide (rGO) as a double-layer sensing materials. The Co3O4 micro-nano octahedra were synthesized by direct growth from electrospun fiber templates calcined in ambient air. The double-layer rGO/Co3O4-HFIP sensing materials presented high selectivity toward DMMP (sarin agent simulant, dimethyl methyl phosphonate) versus rGO/Co3O4 and Co3O4 sensors after the exposure to various gases owing to hydrogen bonding between the DMMP molecules and Co3O4-HFIP. The rGO/Co3O4-HFIP sensors showed high stability with a response signal around 11.8 toward 0.5 ppm DMMP at 125 °C, and more than 75 % of the initial response was maintained under a saturated humid environment (85 % relative humidity). These results prove that these double-layer inorganic–organic composite sensing materials are excellent candidates to serve as optimal gas-sensing materials. 相似文献
5.
Hypericin content of methanolic extracts of dried flowers, leaves, stems, and roots of Hypericum triquetrifolium (Turra) were determined by HPLC. Conversion of protohypericin to hypericin was achieved by exposing samples to light for 30 min immediately before HPLC analysis. External standard calibration was used to quantify hypericin. Leaves showed the highest hypericin content of 0.36% w/w. Total aerial parts contained 0.43% w/w of hypericin. The relatively high hypericin content of the H. triquetrifolium in this study encourages the introduction, cultivation, and biological evaluation of hypericum specie in Jordan. 相似文献
6.
Mashhour I. M. Alali 《代数通讯》2013,41(1):71-75
The purpose of this article is to determine Aut(A) where A is a semifield of order 54 admitting an automorphism group E ? Z 2 × Z 2 acting freely on A. 相似文献
7.
A B-Injector in an arbitrary finite group G is defined as a maximal nilpo-tent subgroup of G, containing a subgroup A of G of maximal order satisfying class(A) ≥ 2. Among other results the B-Injectors of the sporadic groups J1,J2,J4, M24 are determined. 相似文献
8.
A methodology is presented for investigating the dynamics of heterogeneous media using the nonlocal continuum model given
by the peridynamic formulation. The approach presented here provides the ability to model the macroscopic dynamics while at
the same time resolving the dynamics at the length scales of the microstructure. Central to the methodology is a novel two-scale
evolution equation. The rescaled solution of this equation is shown to provide a strong approximation to the actual deformation
inside the peridynamic material. The two scale evolution can be split into a microscopic component tracking the dynamics at
the length scale of the heterogeneities and a macroscopic component tracking the volume averaged (homogenized) dynamics. The
interplay between the microscopic and macroscopic dynamics is given by a coupled system of evolution equations. The equations
show that the forces generated by the homogenized deformation inside the medium are related to the homogenized deformation
through a history dependent constitutive relation. 相似文献
9.
10.
Antioxidant activity and total phenolic content of aqueous and methanolic extracts of Jordanian plants: an ICBG project 总被引:2,自引:0,他引:2
Alali FQ Tawaha K El-Elimat T Syouf M El-Fayad M Abulaila K Nielsen SJ Wheaton WD Falkinham JO Oberlies NH 《Natural product research》2007,21(12):1121-1131
As part of an International Cooperative Biodiversity Groups (ICBG) program to study Jordan's biodiversity, the relative levels of antioxidant activity and the total phenolic content of aqueous and methanolic extracts of a total of 95 plant species, all of Jordanian origin and those collected at random, have been measured. The total phenolic content of aqueous and methanolic extracts of the investigated plant species ranged from 4.4 to 78.3 mg and from 2.1 to 52.8 mg gallic acid equivalents g(-1) dry weight, respectively, while the total antioxidant capacity ranged from 20.0 to 916.7 and from 15.1 to 915.6 micromol Trolox equivalents g(-1) dry weight, respectively. Based on this collection, approximately 5% of assayed plants showed high levels of antioxidant activity. There was a significant linear correlation between antioxidant activity and total phenolic content for aqueous and methanolic extracts, suggesting that phenolic compounds were the predominant antioxidant components in the investigated plant species. Interestingly, a few of the collected plants had high-antioxidant activity yet "low" phenolic content includes Ceratonia siliqua and Viscum cruciatum. These plants may serve as sources of antioxidants with new chemotypes. 相似文献