Chromene is considered a fused pyran ring with a benzene ring, which is found in many plants and is part of many important compounds such as anthocyanidins, anthocyanins, catechins, and flavanones. These compounds are included under the headings "flavonoids" and "isoflavonoids." These compounds are well known as bioactive molecules with wide medicinal uses. According to these pharmacokinetic characteristics, many researchers are giving more attention to this type of compound and its derivatives. Many chromene derivatives have been synthesized to study their biological effects for the treatment of many diseases. Furthermore, the researcher displayed wide interest in finding new methods for synthesizing chromene derivatives. These methods depend on utilizing a new catalyst to increase the yield of this reaction or reduce the time of the reaction. On the other hand, new methods were found by using a new reactant and a new substrate. This review will present the most recent important methods for the synthesis of chromene derivatives as well as an examination of their biological activity.
To prepare a new ligand, many compounds were used to synthesize Schiff-Mannich base, such as isatin, Para chloro Aniline, 2-mercaptobenzimidazole and indole. The resulting compound 1-((2-((1H-indol-1-ylthio)-1H-benzo[d]imidazol1-yl)methyl)-3-(4-chlorophenylimino)indolin-2-one (L). (L) was used to create a series of metal ion complexes with Co (II), Ni (II), Cu (II), Pd (II), Pt (IV), and Au (III). C.H.N.S., FTIR, mass spectra UV-ViS, 1H-NMR, 13CNMR, magnetic moment, and molar conductivity were used to characterize all of these compounds. Except for the palladium(II) and gold(III) complexes, all of the produced complexes had an octahedral geometry, according to the data. The antibacterial activity of the produced compounds was tested by usin
... Show MoreThe present work involved four steps: First step include reaction of acrylamide ,N-?-Methylen-bis(acryl amide) and N-tert Butyl acryl amide with poly acryloyl chloride in the presence of triethyl amine (Et3N) as catalyst, the second step include homopolymerization of all products of the first step by using benzoyl peroxide(BPO) as initiator in (80-90)Co in the presence of Nitrogen gas(N2). In the third step the poly acrylimide which prepare in second step was convert into potassium salt by using alcoholic potassium hydroxide solution. Fourth step include Alkylation of the prepared polymeric salts in third step by react it with different alkyl halides(benzyl chloride, allylbromide , methyl iodide) by using DMF as solvent for(10-12) hours.
... Show MoreThroughout Agriculture has mostly relied on the use of natural fertilizers throughout human history, which are compounds that increase the nitrogen levels in the soil. Modern agriculture was made possible by the introduction of synthetic fertilizers at the end of the 19th centuryproduction of agriculture. Their application enhanced crop yields and sparked an agricultural revolution unlike anything the world had ever seen.In the near future, synthetic fertilizers are anticipated to continue to have a significant impa ct on human life, both positively and negatively. They are frequently utilized for producing all t ypes of crops and are essential to plant growth. The significance of synthetic fertilizers is their ability to provide the soil w
... Show MoreBackground: Head and neck squamous cell carcinoma is the sixth most common cancer world wide. Despite greater emphasis on multi-modality therapy including surgery, radiation and chemotherapy, advanced stage head and neck squamous cell carcinoma continues to have poor 5-year survival rates (0-40%) that have not significantly improved in the last (30) years. To improve outcomes for this deadly disease , It is required a better understanding of the mechanisms underlying head and neck squamous cell carcinoma tumor growth, metastasis, and treatment resistance. This study evaluates the Immunohistochemical expression of E-cadherin and CD44 adhesion molecules in OSCC and to correlate the expression of either marker with each other, with lymph node
... Show MoreIn this work magnetite/geopolymer composite (MGP) were synthesized using a chemical co-precipitation technique. The synthesized materials were characterized using several techniques such as: “X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), vibrating sample-magnetometer (VSM), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET) and Barrentt-Joyner-Halenda (BJH)” to determine the structure and morphology of the obtained material. The analysis indicated that metal oxide predominantly appeared at the shape of the spinel structure of magnetite, and that the presence of nano-magnetite had a substantial impact on the surface area and pore st
... Show More
Abstract
The Classical Normal Linear Regression Model Based on Several hypotheses, one of them is Heteroscedasticity as it is known that the wing of least squares method (OLS), under the existence of these two problems make the estimators, lose their desirable properties, in addition the statistical inference becomes unaccepted table. According that we put tow alternative, the first one is (Generalized Least Square) Which is denoted by (GLS), and the second alternative is to (Robust covariance matrix estimation) the estimated parameters method(OLS), and that the way (GLS) method neat and certified, if the capabilities (Efficient) and the statistical inference Thread on the basis of an acceptable
... Show MoreRehabilitation robotics has developed into an interdisciplinary field which uses mechanical design and control theory and optimization techniques together with information technologies to create better recovery results for people who suffer from motor disabilities. The present review assesses rehabilitation robotics research through engineering application studies which use more than 120 peer-reviewed articles published between 2014 and 2024. The discussion covers four main areas which include control strategies that start from basic PID methods and extend to sophisticated adaptive and intelligent control systems. The study utilizes bio-inspired and metaheuristic optimization methods to enhance system functionality and develop control paths
... Show MoreThis paper shews how to estimate the parameter of generalized exponential Rayleigh (GER) distribution by three estimation methods. The first one is maximum likelihood estimator method the second one is moment employing estimation method (MEM), the third one is rank set sampling estimator method (RSSEM)The simulation technique is used for all these estimation methods to find the parameters for generalized exponential Rayleigh distribution. Finally using the mean squares error criterion to compare between these estimation methods to find which of these methods are best to the others
In this present research, new derivatives were designed from metoclopramide skeleton and after studying the effect of these materials as corrosion inhibitors for the carbon steel 45 in HCl solution. Metoclopramide as the starting compound was diazotized with sodium nitrate and concentrated HCl in below 5 oC to afford diazonium salt that coupled in a basic medium with active compounds like 1-Nitrose-2-naphthol and 2-Nitrose-1-naphthol to afforded azo compounds M1 and M2 respectively. The newly designed compounds identify their structure by distinct spectral techniques involving FTIR and 1H-NMR. Also several of its physical properties were determined. These compounds were studied as corrosion inhibitors in an acidic medium at different t
... Show Moreأن إحدى اكبر مشاكل الصحة العالمية هي ظهور مقاومة الميكروبية للأدوية الشائعة لذلك هناك حاجة ملحة لمضادات جرثومية جديدة ذات نشاط أحيائي معزز .في هذا الدراسة, تم تحضير خمسة مشتقات جديدة من الكينولين A,B,C,D وEكمضادات جرثومية. تم فحص بنية المركبات المحضرة باستخدام UV light , FTIR NMR . تم استخدام طريقة الانتشار بالحفر في الطبق لاختبار الخصائص المضادة للبكتريا للمركبات المحضرة في المختبر ضد نوعين من البكتريا الموجبة
... Show More