210 research outputs found

    Synthesis of caffeine/maleic acid co-crystal by ultrasound assisted slurry co-crystallization

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    YesA green approach has been used for co-crystallization of non-congruent co-crystal pair of caffeine – maleic acid using water. Ultrasound is known to affect crystallization hence the effect of high power ultrasound on the ternary phase diagram has been investigated in detail using a slurry co-crystallization approach. A systematic investigation was performed to understand how the accelerated conditions during ultrasound assisted co-crystallization will affect different regions of the ternary phase diagram. Application of ultrasound showed considerable effect on the ternary phase diagram; principally on caffeine/maleic acid 2:1 (disappeared) and 1:1 co-crystal (narrowed) regions. Also, the stability regions for pure caffeine and maleic acid in water were narrowed in the presence of ultrasound, expanding the solution region. The observed effect of ultrasound on the phase diagram was correlated with solubility of caffeine and maleic acid and stability of co-crystal forms in water

    Proton Transfer, Hydrogen Bonding, and Disorder: Nitrogen Near-Edge X-ray Absorption Fine Structure and X-ray Photoelectron Spectroscopy of Bipyridine-Acid Salts and Co-crystals

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    The sensitivity of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to Brønsted donation and the protonation state of nitrogen in the solid state is investigated through a series of multicomponent bipyridine–acid systems alongside X-ray photoelectron spectroscopy (XPS) data. A large shift to high energy occurs for the 1s → 1π* resonance in the nitrogen K-edge NEXAFS with proton transfer from the acid to the bipyridine base molecule and allows assignment as a salt (C═NH+), with the peak ratio providing the stoichiometry of the types of nitrogen species present. A corresponding binding energy shift for C═NH+ is observed in the nitrogen XPS, clearly identifying protonation and formation of a salt. The similar magnitude shifts observed with both techniques relative to the unprotonated nitrogen of co-crystals (C═N) suggest that the chemical state (initial-state) effects dominate. Results from both techniques reveal the sensitivity to identify proton transfer, hydrogen bond disorder, and even the potential to distinguish variations in hydrogen bond length to nitrogen

    A robust binary supramolecular organic framework (SOF) with high CO2 adsorption and selectivity

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    A robust binary hydrogen-bonded supramolecular organic framework (SOF-7) has been synthesized by solvothermal reaction of 1,4-bis-(4-(3,5-dicyano-2,6 dipyridyl)dihydropyridyl)benzene (1) and 5,5’-bis-(azanediyl)-oxalyl-diisophthalic acid (2). Single crystal X-ray diffraction analysis shows that SOF-7 comprises 2 and 1,4-bis-(4-(3,5-dicyano-2,6-dipyridyl)pyridyl)benzene (3), the latter formed in situ from the oxidative dehydrogenation of 1. SOF-7 shows a three-dimensional four-fold interpenetrat-ed structure with complementary O−H···N hydrogen bonds to form channels that are decorated with cyano- and amide-groups. SOF-7 exhibits excellent thermal stability and sol-vent and moisture durability, as well as permanent porosity. The activated desolvated material SOF-7a shows high CO2 sorption capacity and selectivity compared with other po-rous organic materials assembled solely through hydrogen bonding

    Polymorphism: an evaluation of the potential risk to the quality of drug products from the Farmácia Popular Rede Própria

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    Polymorphism in solids is a common phenomenon in drugs, which can lead to compromised quality due to changes in their physicochemical properties, particularly solubility, and, therefore, reduce bioavailability. Herein, a bibliographic survey was performed based on key issues and studies related to polymorphism in active pharmaceutical ingredient (APIs) present in medications from the Farmácia Popular Rede Própria. Polymorphism must be controlled to prevent possible ineffective therapy and/or improper dosage. Few mandatory tests for the identification and control of polymorphism in medications are currently available, which can result in serious public health concerns

    Infrequent use of medicinal plants from India in snakebite treatment

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    Snakes have fascinated humankind for millennia. Snakebites are a serious medical, social, and economic problem that are experienced worldwide; however, they are most serious in tropical and subtropical countries. The reasons for this are 1) the presence of more species of the most dangerous snakes, 2) the inaccessibility of immediate medical treatment, and 3) poor health care. The goal of this study was to collect information concerning rare, less utilized, and less studied medicinal plants. More than 100 plants were found to have potential to be utilized as anti-snake venom across India. Data accumulated from a variety of literature sources revealed useful plant families, the parts of plants used, and how to utilize them. In India, there are over 520 plant species, belonging to approximately 122 families, which could be useful in the management of snakebites. This study was conducted to encourage researchers to create herbal antidotes, which will counteract snake venom. These may prove to be an inexpensive and easily assessable alternative, which would be of immense importance to society. Plants from families such as Acanthaceae, Arecaceae, Apocynaceae, Caesalpiniaceae, Asteraceae, Cucurbitaceae, Fabaceae, Euphorbiaceae, Lamiaceae, Rubiaceae, and Zingiberaceae are the most useful. In India, experts of folklore are using herbs either single or in combination with others. Keywords: Appraise traditional medicinal plants, Ethnomedicine, India, Snake antiveno

    Economic Analysis of Micropropagation of Dragon Fruit (Hylocereus undatus (Haw.) Britton and Rose)

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    Cultivation of dragon fruit is rising in many topical and sub-tropical countries because of its high nutritional and medicinal values and is highly remunerative for the farmers. However, the supply of planting material is a bottleneck in meeting the increasing demand. With the upsurge in requirement for planting materials and the slow growth of the cactus, the conventional methods of stem cutting, which is the only source of acquiring planting materials at present, cannot meet the demand. Micropropagation which ensures the crop's clonal fidelity and availability of planting material throughout the year can be an alternative. Considering the higher cost of micropropagation, an economic analysis of in vitro regeneration for thousand plants was calculated and compared with the conventional stem cuttings. Cost of tissue cultured plantlets (Rs. 20.02) /plant) was found to be higher than the conventional method (Rs. 14.93 per plant). The major cost involved in micropropagation is attributed to the cost of skilled labours required for multiple sub-cultures, followed by the hardening media and tissue culture growth media. Nevertheless, the cost of tissue cultured plantlets is far lesser than the market price (Rs. 40/plant at university of Horticultural Sciences, Bagalkot). Hence, considering the clonality, uniformity and disease freeness of tissue cultured plantlets, micropropagation of dragon fruit may be considered feasible for both the producers and farmers. A further cost of production may be reduced with training skilled labours to improve their efficiency and other cheap sources of potting media may be explored
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