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Shaheen Faizi Humaira Siddiqi Aneela Naz Samina Bano Lubna 《Helvetica chimica acta》2010,93(3):466-481
An H/D exchange process in patuletin ( 1 ) and its derivatives in D‐donor solvents (e.g., CF3COOD), which occurs regioselectively at C(8) was observed for the first time during NMR studies. The effect of substituents and temperature on the deuteration of various flavonoids (see Fig. 1) which include apigenin, chrysin, galangin, kaempferol, luteolin, morin, myricetin, patuletin, patulitrin, and quercetin, as well as derivatives of patuletin was examined extensively under NMR conditions. The rate constant of deuteration at C(8) of patuletin ( 1 ) and two flavones, luteolin ( 3 ) and apigenin ( 12 ), was also determined in CF3COOD. The D‐atom was introduced into the flavonoids via a keto–enol tautomerism (Scheme 1). During these studies, monodeuterated patuletin was also obtained as a new compound. The examined flavonoids have been reported to possess significant pharmacological activities, and their deuterated derivatives would be of importance for the identification and quantification of these compounds in biological matrices. 相似文献
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Samina Rubnawaz Waqas Khan Kayani Nosheen Akhtar Rashid Mahmood Asif Khan Mohammad K. Okla Saud A. Alamri Ibrahim A. Alaraidh Yasmeen A. Alwasel Bushra Mirza 《Molecules (Basel, Switzerland)》2021,26(16)
Ajuga bracteosa Wall. ex Benth. is an endangered medicinal herb traditionally used against different ailments. The present study aimed to create new insight into the fundamental mechanisms of genetic transformation and the biological activities of this plant. We transformed the A. bracteosa plant with rol genes of Agrobacterium rhizogenes and raised the regenerants from the hairy roots. These transgenic regenerants were screened for in vitro antioxidant activities, a range of in vivo assays, elemental analysis, polyphenol content, and different phytochemicals found through HPLC. Among 18 polyphenolic standards, kaempferol was most abundant in all transgenic lines. Furthermore, transgenic line 3 (ABRL3) showed maximum phenolics and flavonoids content among all tested plant extracts. ABRL3 also demonstrated the highest total antioxidant capacity (8.16 ± 1 μg AAE/mg), total reducing power, (6.60 ± 1.17 μg AAE/mg), DPPH activity (IC50 = 59.5 ± 0.8 μg/mL), hydroxyl ion scavenging (IC50 = 122.5 ± 0.90 μg/mL), and iron-chelating power (IC50 = 154.8 ± 2 μg/mL). Moreover, transformed plant extracts produced significant analgesic, anti-inflammatory, anticoagulant, and antidepressant activities in BALB/c mice models. In conclusion, transgenic regenerants of A. bracteosa pose better antioxidant and pharmacological properties under the effect of rol genes as compared to wild-type plants. 相似文献
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Sattar FA Ahmed F Ahmed N Sattar SA Malghani MA Choudhary MI 《Natural product communications》2012,7(2):195-196
A controlled study was conducted to determine the efficiency of a topical ointment prepared from the stem extract of Morinda citrifolia against cutaneous leishmaniasis. Similarly, the in vitro antileishmanial activity of morindicone and morinthone isolated from the extract were investigated against Leishmania major. These compounds displayed good activity. Out of 40 patients, 50% showed an excellent response and 30% exhibited good improvement. 相似文献
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Fonseca SM Barker AL Ahmed S Kemp TJ Unwin PR 《Chemical communications (Cambridge, England)》2003,(8):1002-1003
Using scanning electrochemical microscopy (SECM) we have measured quantitatively the depletion of O2 during the photodegradation of 4-chlorophenol at supported TiO2 films for the first time and established the connection between Cl-formation and O2 depletion rates. 相似文献
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S. Arshad Jamal Samina Qureshi Samina Noor Ali M. Iqbal Choudhary Atta-Ur-Rahman 《Chemistry of Heterocyclic Compounds》1995,31(9):1047-1059
Four bioactive withanolides withalactone (1), withaoxylactone (2), quresimine-A (4-hydroxy, 3-methoxy-5, 6-epoxy-(22R)-witha-24-enolide) (3) and quresindne-B (4, 27 dihydroxy-3-methoxy-5, 6-epoxy-(22R)-witha-24-enolide (4) have been isolated from the herbs of Withania somnifera, Dunal (Solanaceae). The elucidation of their structures is based on extensive spectroscopic studies, such as1H-NMR, COSY-45°, HMBC, HMQC HOHAHA, E.I., FAB (+ ve), and HR MS, etc.Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1200–1213, September, 1995. 相似文献
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Kalim Ullah Khan Samina Roohi Mohammad Rafi Rizwana Zahoor Zafar Iqbal Mushtaq Ahmad 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(1):225-228
Labelling of 5-aminolevulinic acid (5-ALA) with 99mTc was achieved by using SnCl2·2H2O as reducing agent. Radiochemical purity and labelling efficiency was determined by instant thin layer chromatography/paper chromatography. Efficiency of labelling was dependent on many parameters such as amount of ligand, reducing agent, pH, and time of incubation. 99mTc labelled 5-ALA remained stable for 24 h in human serum. Tissue biodistribution of 99mTc-5-ALA was evaluated in Sprague–Dawley rats. Biodistribution study (% ID/g) in rats revealed that 99mTc-5-ALA was accumulated significantly in liver, spleen, stomach and intestine after half hour, 4 and 24 h. Significant activity was noted in bladder and urine at 4 h. High liver uptake of 99mTc-5-ALA makes it a promising liver imaging agent. 相似文献
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Raghava S Aquil S Bhattacharyya S Varadarajan R Gupta MN 《Journal of chromatography. A》2008,1194(1):90-95
The maltose binding protein (MBP) affinity tag has been extensively used for protein purification. A commercial grade cationic starch could precipitate MBP or an MBP-tagged protein quantitatively by simultaneous addition of 10% (w/v) polyethylene glycol (PEG) and 50 mM calcium chloride. The precipitated MBP or MBP-tagged protein could be selectively dissociated by suspending the precipitate in 1 M NaCl. In the case of a soluble MBP fusion with a fragment of human immunodeficiency virus protein gp120, 38% of the contaminating proteins could be removed by precipitation with PEG/CaCl(2) and 100% of the fusion protein was recovered. In all cases, the purified proteins showed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the expected changes in fluorescence emission spectra upon binding to maltose. 相似文献