Ameer Fawad Zahoor

Recent trends in ring opening of epoxides by amines as nucleophiles

ABSTRACT β-Amino alcohols are versatile intermediates in the synthesis of various biologically potent compounds, which can also be achieved by ring opening of epoxides by amines. In the present review, focus has been placed on the ring opening of epoxides with amines under a variety of reaction parameters reported during 2011–2015. All the factors that resulted in excellent yields and high regioselectivity, are environmentally benign, and use mild conditions have been discussed in detail. In addition, the applications of these methods in the synthesis of biologically active compounds such as β-blockers have also been described. GRAPHICAL ABSTRACT

Synthesis and Consecutive Reactions of α-Azido Ketones: A Review

This review paper covers the major synthetic approaches attempted towards the synthesis of α-azido ketones, as well as the synthetic applications/consecutive reactions of α-azido ketones.

Regioselective synthesis of 2-(bromomethyl)-5-aryl-thiophene derivatives via palladium (0) catalyzed suzuki cross-coupling reactions: as antithrombotic and haemolytically active molecules

BackgroundIt is seen that the regioselective functionalizations of halogenated heterocycles play an important role in the synthesis of several types of organic compounds. In this domain, the Suzuki-Miyaura reaction has emerged as a convenient way to build carbon-carbon bonds in synthesizing organic compounds. Some of the most important applications of these reactions can be seen in the synthesis of natural products, and in designing targeted pharmaceutical compounds. Herein, we present the regioselective synthesis of the novel series of 2-(bromomethyl)-5-aryl-thiophenes 3a-i,via Suzuki cross-coupling reactions of various aryl boronic acids with 2-bromo-5-(bromomethyl)thiophene (2).ResultsThe synthesized compounds were screened for their haemolytic and antithrombolytic activities. The novel compounds 3f, 3i showed highest 69.7, 33.6% haemolysis of blood cells, respectively. The antithrombolytic activity of the compounds was found to be within low to moderate against human blood clot. The compound 3i showed potent clot lysis (31.5%).ConclusionsConsidering these results, it is concluded that the synthesized compounds can be used as a promising source of therapeutic agents.

Synthesis of ciprofloxacin-based compounds: A review

ABSTRACT Ciprofloxacin is a broad-spectrum antibiotic that plays an important role in inhibiting the growth of both Gram-positive and Gram-negative bacteria. Medicinal chemists are extensively involved in the synthesis of novel ciprofloxacin derivatives, in search of new ciprofloxacin-based drugs with enhanced activity. This review article summarizes the major synthetic approaches involved in the synthesis of ciprofloxacin-based molecules. GRAPHICAL ABSTRACT

Ring opening of epoxides with C-nucleophiles

Ring opening of epoxides has been an area of interest for organic chemists, owing to their reactivity toward nucleophiles. Such reactions yield important products depending on the type of nucleophiles used. This review article covers the synthetic approaches (1991–2015) used for the ring opening of epoxides via carbon nucleophiles.

Extraction, isolation, and identification of various environment friendly components from cock's comb (Celosia argentea) leaves for allelopathic potential

In this study, the aqueous extract of leaves of the plant cocks comb (Celosia argentea) was fractioned into five batches using n-hexane, dichloromethane, ethyl acetate, and n-butanol, respectively. High performance liquid chromatography analysis of the methanol re-dissolved residues of 3 polar fractions, including dichloromethane, ethyl acetate, and n-butanol separately which exhibited altogether 12 compounds identified as 4-hydroxycinnamic acid (p-coumaric acid), 4-hydroxybenzoic acid, protocatechuic acid, caffeic acid, m-coumaric acid, gallic acid, 4-hydroxybenzaldehyde, m-hydroxybenzaldehyde, 2,4-dihydroxybenzoic acid, pyrogallol, 3,5-dihydroxybenzoic acid, and genetic acid was categorized by retention time using known compounds. Similarly, the mass confirmation of most of the identified compounds was achieved by injecting 20 µl of composite sample of these three polar fractions into liquid chromatography–mass spectrometry. Similarly, the physiochemical analysis of C. argentea aqueous extract showed the presence of various constituents such as phenols, flavonoids, tannins, and glycosides. All four organic fractions were examined for phytotoxicity against Lepidium sativum. Analysis of variance showed significant differences among these fractions against germination and growth of L. sativum. Further allelopathic effects appeared to be concentration dependent. Thus, C. argentea may prove effective as a substitute of herbicides to control the weeds like L. sativum from attacking crops and to protect the environment from the health hazard effects of herbicides.

A comparative study on the status of Zn and Cu in diabetic and non diabetic males in Punjab, Pakistan

Minerals play a considerable role in the prolongation of all biological and psychological processes in the body. The present study was aimed to determine and to compare the concentration of zinc and copper in the serum samples of diabetic and non diabetic males of different age groups, that is, between one to seventy five years. Fasting blood samples of diabetic males as well as of non diabetics of selected age groups were collected for the study. Blood serum was obtained after centrifugation of blood samples. Level of zinc and copper in blood serum samples were determined by using atomic absorption spectrophotometer. The data obtained was processed statistically by using student’s t- test. A highly, significant (p<0.01) lower levels of zinc and highly, significant (p<0.01) higher levels of copper were found in blood serum of diabetic males when they were compared with non diabetic ones. The results reflect that the diabetic patients had a higher mean concentration of Zn (0.577 ppm), lower mean concentration of Zn (0.467 ppm), higher mean concentration of Cu (2.713 ppm) and lower mean concentration of Cu (2.207 ppm). It has also been represented by our results that the non diabetic males had higher mean concentration of Zn (1.94 ppm), lower mean concentration of Zn (0.937 ppm), higher mean concentration of Cu (1.31 ppm) and lower mean concentration of Cu (1.077 ppm). It has been concluded that the diabetic males of all age groups are deficient of zinc and they contain a higher level of copper in their blood serum.

Ring-opening reactions of oxetanes: A review of methodology development and synthetic applications

ABSTRACT Ring-opening reactions of oxetanes yield important functionalized products depending upon the nature of nucleophiles as well as substitution pattern on the oxetane ring. Ring opening of oxetanes can be carried out under a variety of reaction conditions. In this review article, an up-to-date overview of major synthetic methodologies involved in the ring opening of oxetanes as well as their synthetic applications has been presented. GRAPHICAL ABSTRACT

Toxic and some essential metals in medicinal plants used in herbal medicines: A case study in Pakistan

The levels of some heavy metals in eight different medicinal plant samples along with soils were collected from two different locations from salt range of Punjab, Pakistan in order to evaluate those vital metals involved in human health implications. These plant species were: Dodonaea viscosa, Withania somnifera, Solanum nigrum, Calotropis gigantea, Mentha spicata, Paganum hermala, Cannabis sativa, Adhatoda vasica, especially those used in the treatment of diseases and their long term usage. The evaluated metals were cadmium (Cd), Nickel (Ni), Chromium (Cr) and lead (Pb). Atomic absorption spectrophotometry (wet digestion) was used for the analyses, and content of metals per sample was expressed as mg/kg. The analysis of variance revealed that there were significant effects of site variation on medicinal species in Ni and Cr contents while the opposite were observed in case of Pb and Cd at location I. The Ni concentrations found in medicinal plants varied significantly while Pb, Cd and Cr were evident as non significant at location II. There was positive non significant correlation of Pb and Cr among soil and plant while negative non significant for Ni and Cd at both locations. The findings suggest that the use of these plant species for the management of diseases will not cause heavy metal toxicity and may be beneficial to the users in cases of micronutrient deficiency, as these metals were found to be present in readily bioavailable form.

Development of environmental friendly synthetic strategies for Sonogashira cross coupling reaction: An update

Abstract Sonogashira cross coupling is a well-known reaction for the formation of carbon-carbon bond. It involves the coupling of aryl halides with terminal alkynes to synthesize versatile functionalized alkyne scaffolds having diverse applications. Many of the natural products and important pharmaceutical drugs can be obtained through this reaction. In this regard, hectic progress has been put by the synthetic chemists to make this cross coupling more effective. This review article discloses mild and environmental friendly reaction conditions of Sonogashira cross coupling developed during 2013-2018. Graphical Abstract