Chemical Biology Letters <p>Chemical Biology Letters is a peer reviewed indexed international journal for publication of research and review articles from Medicinal Chemistry, BioChemistry, Chemical Biology, Drug Development and Drug Delivery related studies.</p> ScienceIn Publishing en-US Chemical Biology Letters 2347-9825 An economic and efficient synthesis of acid-labile glycerol based β-thiopropionate esters for potential application in drug delivery <p>Acid labile linkers have been used widely for various biomedical applications with preferential applications in drug delivery. In this report, we have synthesized, glycerol based b-thiopropionate esters having an acid-labile β-thiopropionate linker with Michael addition reaction between hydrophobic thiol and hydrophilic tri-glycerol diacrylate. The solvent free reaction and purification by simply solvent extraction instead of any sophisticated chromatographic techniques provide an upper edge for their application in biomedical or other fields. These β-thiopropionate esters can potentially be used for the delivery and release of hydrophobic drugs at acidic sites particularly in cancer cells.</p> Pooja Kumari Monika Gulia Shilpi Gupta Devender Singh Sumit Kumar Copyright (c) 2021 ScienceIn 2021-02-15 2021-02-15 8 2 45 49 Assessing the antimycobacterial activity of the bioactive fractions of the Indian medicinal plant - Justicia adhatoda L. <p><em>Justicia adhatoda L.</em> is an Indian medicinal plant traditionally used to treat respiratory ailments in Ayurvedic and Unani medicines. &nbsp;It is widespread in the Indian subcontinent. The plant leaves are known to have broad range of pharmacological activities including analgesic, anti-inflammatory, antispasmodic and antibacterial properties. Some studies have highlighted the antimicrobial effects of its major bioactive components like vasicine and vasicinone However, not much work has been done to explore the enormous benefits that the bioactive components might hold. Hence, in the present study, we explored the plant for its potential as an effective anti- mycobacterial agent. We aim to investigate the antimycobacterial effect of <em>J. adhatoda</em> L. plant leaf extracts on <em>Mycobacterium smegmatis </em>and<em> Mycobacterium bovis</em> (BCG) and identify, and isolate th bioactive component(s) for the plant leaf extract. The isolated components were also analyzed further for their antimycobacterial activity in synergy with Isoniazid. The leaves of <em>J. adhatoda L.</em> were powdered and extracted with ethanol, water, ethyl acetate, and hexane and antimycobacterial activity was assessed by MABA. The ethanol extract showed &gt;96% and 98% reduction in colony-forming units (CFU) at 100µg/ml on <em>Mycobacterium smegmatis</em> and <em>Mycobacterium bovis</em> (BCG) respectively. Active phytoconstituent from ethanol extract was isolated and further fractionated via Prep-TLC. They were bioassayed against <em>M. smegmatis</em> and <em>M. bovis</em> (BCG) to study cytotoxicity, synergy, and external damage on the bacteria. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were carried out on treated bacilli to observe the external and internal cellular damage. The isolated fractions showed strong anti-mycobacterial activity, with low cytotoxicity and synergism when used with isoniazid. When subjected to electron microscopy, the fractions were found to adversely affect the cell wall and membrane of BCG, causing cytoplasmic leakage. Our study demonstrated that the active fractions isolated from <em>J. adhatoda L.</em> could be evaluated further for potentially effective anti-mycobacterial agents.</p> Smita Mishra Manisha Khatri Varsha Mehra Copyright (c) 2021 ScienceIn Publishing 2021-07-07 2021-07-07 8 2 67 78 Antarctic cyanobacterium Nostoc CCC537, a new source of γ-linolenic acid and its antibacterial potential <p>Unsaturated fatty acids are one of an important component of our healthy diet as needed for various physiological functions as well as it has medicinal significance. The Gamma linolenic acid (GLA), the pharmaceutically important fatty acid, was isolated from the <em>Antarctic cyanobacetrium</em>, <em>Nostoc</em><sub>CCC537</sub>. The antibacterial potential of GLA was evaluated against <em>Staphylococcus aureus</em> ATCC25923, <em>Pseudomonas aeruginosa</em> ATCC27853, <em>Salmonella typhi</em> MTCC3216, <em>Escherichia coli</em> ATCC25992 and <em>Enterobacter</em> <em>aerogene</em>s MTCC2822. It was observed that GLA production in the cyanobacterium was also regulated by alterations in phosphate or nitrate levels during growth along with temperature. A doubling in the phosphate concentration (116 μM) over that routinely used (58 μM) in the diazotrophic medium, enhanced GLA production 20.5%, while the biomass yield decreased to 7.3% of the control. GLA production, however, decreased to 18% or 23% in 5 mM or 10 mM nitrate, respectively. A downshift in growth temperature to 10<sup>o</sup>C from 20<sup>o</sup>C enhanced GLA production. It is suggested that the Antarctic cyanobacterium may also act as a source of an antibacterial agent as well as GLA.</p> Deepali Ravi Kumar Asthana Gopal Nath Copyright (c) 2021 ScienceIn Publishing 2021-05-04 2021-05-04 8 2 50 58 Protective effect of hydroethanolic leaf extract of Parquetina nigrescens against D-galactose-induced neurotoxicity in male Wistar rats <p>This study investigated the effect of hydroethanolic leaf extract of <em>Parquetina nigrescens</em> (HELEPN) on D-galactose induced neurotoxicity in male Wistar rats. Brain damage was induced by the administration of 300mg/kg b.w of D-galactose subcutaneously for six weeks while HELEPN treatments (250mg and 500 mg/kg b.w) were given orally for four weeks. After the study, rats were sacrificed and brain tissues collected for biochemical analysis. The concentrations of Advanced Glycation end products (AGEs), Tumour Necrosis Factor α (TNF-α), 8-dehydroyxguanosine (8-OHDG) and Caspase 3 activity was done using Enzyme linked immunosorbent assay (ELISA) kits.&nbsp; Levels of malondialdehyde (MDA), glutathione, Nitric oxide and activities of Acetycholinestrease (AChE), Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx) as well as DNA fragmentation index (DFI) were determined using standard techniques. HELEPN administration attenuated D-galactose-induced brain alterations through decreased MDA level and increased activities of SOD, CAT as well as elevated glutathione concentration. HELEPN also improved the activities of brain caspase 3-dependent apoptosis and AChE, TNF-α and DNA fragmentation index. The administration of HELEPN provided neuroprotection against D-galactose-induced brain damage through anti-oxidative, anti-inflammatory as well as anti-apoptotic mechanisms and these protective effects could be as a result of a profile of phytochemicals present in the plant leaves.</p> Lydia Oluwatoyin Ajayi Ademola Olabode Ayeleso Temitope Adenike Oyedepo Copyright (c) 2021 ScienceIn Publishing 2021-07-25 2021-07-25 8 2 79 87 Isolation, synthesis and medicinal applications of Heparin <p>Heparin is a highly sulphated and most negatively charged natural biopolymer belonging to the glycosaminoglycan (GAG) family. This is about a 100-year-old anticoagulant drug. This is equally important for non-anticoagulant diseases also and is the reason for the recent burgeoning of interest in the molecule. Heparin has been isolated from both animal and non-animal sources; however, porcine mucosa remains the FDA-approved source for heparin. For the synthesis, chemical, chemoenzymatic, and biotechnological approaches have been studied. In recent times, the focus is more on synthesizing LMWH, ULMWH, and bioengineered heparins. This article is a compilation about the isolation, synthesis, and medicinal applications of heparin.</p> Saikrushna Jena Ram Singh Copyright (c) 2021 ScienceIn Publishing 2021-06-01 2021-06-01 8 2 59 66