Herein, we report our synthetic studies toward the skyllamycins, a highly modified class of nonribosomal peptide natural products which contain a number of interesting structural features, including the extremely rare α-OH-glycine residue. Before embarking on the synthesis of the natural products, we prepared four structurally simpler analogues. Access to both the analogues and the natural products first required the synthesis of a number of nonproteinogenic amino acids, including three β-OH amino acids that were accessed from the convenient chiral precursor Garner's aldehyde. Following the preparation of the suitably protected nonproteinogenic amino acids, the skyllamycin analogues were assembled using a solid-phase synthetic route followed by a final stage solution-phase cyclization reaction. To access the natural products (skyllamycins A-C) the synthetic route used for the analogues was modified. Specifically, linear peptide precursors containing a C-terminal amide were synthesized via solid-phase peptide synthesis. After cleavage from the resin the N-terminal serine residue was oxidatively cleaved to a glyoxyamide moiety. The target natural products, skyllamycins A-C, were successfully prepared via a final step cyclization with concomitant formation of the unusual α-OH-glycine residue. Purification and spectroscopic comparison to the authentic isolated material confirmed the identity of the synthetic natural products.
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Cell Mol Biol (Noisy-le-grand)
January 2025
Department of Biotechnology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
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January 2025
Department of Chemistry, Rabigh College of Sciences and Arts, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
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Department of Pathobiology and Biomedical Sciences, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan/Ali-Ul-Murtaza Department of Rehabilitation Sciences, Muhammad Institute of Medical and Allied Sciences, Multan, Pakistan.
This study aimed to evaluate the efficacy of vinegar-soaked Ficus carica fruits (VSFCF) for managing cholelithiasis in adults. A parallel-group, single-blinded, randomized controlled trial at Noreen Nishat Welfare Hospital, Khanewal, Pakistan, was conducted from December 2023 to February 2024. Fifty adults with ultrasound-confirmed cholelithiasis were randomly assigned to receive either VSFCF (1 g/kg/day) or ursodiol (600 mg/day).
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Department of Psychiatry, Wenzhou Seventh People's Hospital, Wenzhou, China.
The objective of this study was to evaluate the therapeutic effects of Chiglitazar combined with Rosa roxburghii Tratt (RRT) in inpatients diagnosed with psychiatric disorders and antipsychotic-induced metabolic syndrome (MetS).100 cases were included and divided into the Siglitazar group (n=50) and the Siglitazar + RRT group (n=50) Anthropometric measurements, lipid and glucose metabolism indicators, inflammatory markers and PANSS scores were assessed at baseline, 8 weeks and 12 weeks post-treatment. Both treatment groups exhibited significant reductions in waist circumference and improvements in lipid profiles and glucose metabolism indicators over the 12-week study period.
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Laboratory of Aromatic and Medicinal Plants, Borj Cedria Biotechnology Center, Hammam-Lif, Tunisia.
Plants constitute a source of natural phytochemical components which are widely known for their potential biological activities. This work concerned a study of the antioxidant, anticancer and anti-inflammatory activities of squirting cucumber (Ecballium elaterium L.) parts (flowers, fruits, leaves and stems) using different solvent extracts (cyclohexane, dichloromethane, ethyl acetate, methanol and water).
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