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Microwaves in Lactam Chemistry
Published in Banik Bimal Krishna, Bandyopadhyay Debasish, Advances in Microwave Chemistry, 2018
Dr. Debasish Bandyopadhyay, Bimal Krishna Banik
Amides are an important class of organic compounds that are basically formed by the reaction between carboxylic acids and amines. Cyclic amides, commonly known as lactams, are considered as a special category of compounds because of their prolonged history of use as medicines to cure several ailments, fascinating chemistry, and the future possibility of becoming effective medicines to combat several other diseases. Depending on ring size, lactams can be classified as follows (Figure 10.1): This ring-size nomenclature is derived from the fact that during hydrolysis the lactam produces the corresponding amino acid e.g. the hydrolysis of α-lactams produces α-amino acids.1.α-Lactams: Three-membered cyclic amides2.β-Lactams: Four-membered cyclic amides3.γ-Lactams: Five-membered cyclic lactams4.δ-Lactams: Six-membered cyclic amides5.ε-Lactams: Seven-membered cyclic amides6.ω-Lactams: Eight-membered to medium-sized cyclic amides7.Macrolactams: Higher cyclic amides
Chemical Structure and Manufacturing Processes
Published in Chih-Chang Chu, J. Anthony von Fraunhofer, Howard P. Greisler, Wound Closure Biomaterials and Devices, 2018
The most successful aliphatic polyamide that polymer scientists have synthesized is nylon. Nylon is polymerized either from polycondensation of a dicarboxylic acid and a diamine, or through a ring-opening polymerization of appropriate lactams. Although there are numerous types of nylon, such as nylon 3, 4, 5, 6, 7, 8, 9, 11, 12, 66, and 610, only 66 and 6 are used to make suture materials. The former is more popular in the United States, while the latter is used in Europe. The tradenames of nylon sutures are braided Surgilon® and monofilament Dermalon® with the repeating unit [-NH(CH2)6-NHCO(CH2)4CO-] from Davis & Geck; braided Nurolon® and monofilament Ethilon® with the repeating unit [-NH(CH2)5CO-] from Ethicon; monofilament Monosof® and braided Bralon® from US Suigical; and sheath-core structure Supramid® from S. Jackson. Surgilon nylon suture is coated with silicone, while Nurolon nylon suture is coated with wax. Bralon is coated with a proprietary material. All nylon sutures are sterilized with Co60 γ-irradiation.
Lactams
Published in Rudolf Puffr, Vladimír Kubánek, Lactam-Based Polyamides, 2019
The lactams so far described contain 2 to 20 ring carbon atoms. This family of monomers can be substantially extended if members carrying various substituents on the N and/or C atoms are included. Thus, over one hundred derivatives of mere β-lactams have been synthesized until now; some of them, such as penicillin, found important applications in medicine.1a The stability of small, highly strained cycles is generally increased by substitution. The smallest member, 2-ethanelactam, is known only in the substituted form.1b
Stereoselective synthesis of trans-benzo[d]oxazolyl)phenyl substituted β-lactams decorated with C-3 thio/seleno rich motifs: synthetic intermediates for diverse heterocycles
Published in Journal of Sulfur Chemistry, 2023
Preety Saini, Shalu Thakur, Ankita Garg, S. S. Bari, Aman Bhalla
β-Lactams (azetidin-2-one) are the most imperative pharmacophores in both synthetic and medicinal field, serving as common substructure in numerous bioactive compounds, such as penicillin, cephalosporins, ezetimibe and monobactams [1]. They have been exhibiting a vital role in treating bacterial infections from the past few decades and dominated the antimicrobial regime [2]. The massive use of drugs over decades led to microorganism developing resistance for antibiotics, posing a major challenge in creating effective medications for pharmaceutical industries. As a result, the scientific community has expressed a significant interest to investigate efficient synthetic methodologies for β-lactams and their analogs with improved activity profiles. Moreover, the stereoselective nature of drugs plays indispensable role in deciding the bioactivity of drugs [3]. Owing to the vast importance of stereoselective β-lactams [4], various synthetic methodologies have been reported in literature, amongst which Staudinger reaction provides high stereoselectivity for the development of β-lactams [5]. Therefore, a strategic route for the formation of challenging stereoselective trans β-lactams has been proposed herein.
Degradation of ticarcillin by subcritical water oxidation method: Application of response surface methodology and artificial neural network modeling
Published in Journal of Environmental Science and Health, Part A, 2018
As the most common antibiotics class, β-lactams are effective drugs for their antimicrobial activities based on the β-lactam ring and attached side chains.[7,8] However, they have been identified in various concentration levels (ppb and ppm) in aquatic environments.[8,9] Ticarcillin (Ticar) is an effective kind of broad-spectrum semi-synthetic β-lactam antibiotics and widely used against gram-positive and gram-negative bacteria.[10,11] Moreover, Ticar is one of the 6 most consumed antibiotics for treatment of patients in the oncology department.[12]