Total synthesis of [β-HIle]-nodupetide: effect of ester to amide substitution on its antimicrobial activity.

The increasing prevalence of deaths due to multidrug-resistant bacteria (MDRB) in infectious disease therapy has become a global health concern. This led to the development of new antimicrobial therapeutic agents that can combat resistance to pathogenic bacteria. The utilization of natural peptide compounds as potential antimicrobial agents is very promising.

Correction: Synthesis and anticancer evaluation of [d-Ala]-nocardiotide A.

[This corrects the article DOI: 10.1039/D4RA00025K.].

Structure-Activity Relationship Study and Design Strategies of Hydantoin, Thiazolidinedione, and Rhodanine-Based Kinase Inhibitors: A Two-Decade Review.

Cancer is one of the most prominent causes of the rapidly growing mortality numbers worldwide. Cancer originates from normal cells that have acquired the capability to alter their molecular, biochemical, and cellular traits. The alteration of cell signaling enzymes, such as kinases, can initiate and amplify cancer progression.

Synthesis and anticancer evaluation of [d-Ala]-nocardiotide A.

Cancer is currently one of the biggest causes of death in the world. Like some microorganisms, cancer cells also develop resistance to various chemotherapy drugs and are termed multidrug resistant (MDR). In this regard, there is a need to develop new alternative anticancer agents.

Epimerisation in Peptide Synthesis.

Epimerisation is basically a chemical conversion that includes the transformation of an epimer into another epimer or its chiral partner. Epimerisation of amino acid is a side reaction that sometimes happens during peptide synthesis. It became the most avoided reaction because the process affects the overall conformation of the molecule, eventually even altering the bioactivity of the peptide.

An Overview on Antimalarial Peptides: Natural Sources, Synthetic Methodology and Biological Properties.

Peptide compounds play a significant role in medicinal chemistry as they can inhibit the activity of species that cause malaria. This literature review summarizes the isolation of antimalarial peptides, the synthesis method with the detailed structure and sequences of each peptide, and discusses the biological activity of the isolated and synthesized compounds. The synthetic routes and reactions for cyclic and linear antimalarial peptides are systematically highlighted in this review including preparing building blocks, protection and deprotection, coupling and cyclization reactions until the target compound is obtained.

Synthesis of a Cyclooctapeptide, Cyclopurpuracin, and Evaluation of Its Antimicrobial Activity.

Cyclopurpuracin is a cyclooctapeptide isolated from the methanol extract of seeds with a sequence of cyclo-Gly-Phe-Ile-Gly-Ser-Pro-Val-Pro. In our previous study, the cyclisation of linear cyclopurpuracin was problematic; however, the reversed version was successfully cyclised even though the NMR spectra revealed the presence of a mixture of conformers. Herein, we report the successful synthesis of cyclopurpuracin using a combination of solid- and solution-phase synthetic methods.

Dammarane-Type Triterpenoid from the Stem Bark of (Meliaceae) and Its Cytotoxic Activities.

Two new dammarane-type triterpenoid fatty acid ester derivatives, 3β-oleate-20-hydroxydammar-24-en () and 3β-oleate-20,24-epoxy-25-hydroxydammarane () with a known dammarane-type triterpenoid compound, such as 20-hydroxydammar-24-en-3-on (), were isolated from the stem bark of (C.DC.) Blume.

A new highly selective "off-on" typical chemosensor of Al, 1-(()-(()-(3,5-dichloro-2-hydroxybenzylidene)hydrazono)methyl) naphthalene-2-ol, an experimental and study.

A new promising fluorescent chemosensor based on a 2-hydroxynaphthaldehyde skeleton was successfully synthesized through double imine formation as a yellow solid with an overall chemical yield of 63%. The compound showed UV/Visible maxima of at 394 nm in DMSO. Based on spectroscopic data of FTIR, ToF-HRMS, H-NMR, and C-NMR, the product was characterized as 1-(()-(()-(3,5-dichloro-2-hydroxybenzilydine)hydrazono)methyl)naphthalene-2-ol.

Synthesis of cyclotetrapeptide analogues of c-PLAI and evaluation of their antimicrobial properties.

Antimicrobial peptides (AMPs) are interesting compounds owing to their ability to kill several pathogens. In order to identify new AMPs, c-PLAI analogues were synthesized and evaluated together with their linear precursors for their antimicrobial properties against two Gram-positive bacteria ( and ), two Gram-negative bacteria ( and ), and two fungal strains ( and ). The new c-PLAI analogues were prepared through a combination of solid- and solution-phase syntheses, as previously employed for the synthesis of c-PLAI.

Cytotoxic triterpenoids from Chisocheton pentandrus.

Eleven undescribed triterpenoids (pentandrucines A to K) were isolated from the n-hexane extract of the stem bark of Chisocheton pentandrus (Blanco) Merr. These comprised ten undescribed dammarane-type triterpenoids and one undescribed apotirucallane-type triterpenoid. Additionally, two dammarane-type triterpenoids, four apotirucallane-type triterpenoids and two tirucallane-type triterpenoids were also isolated.

Cytotoxic triterpenoids from the stem bark of .

A seco-apotirucallane-type triterpenoid, namely angustifolianin (), along with three dammarane-type triterpenoids, (20, 24)-epoxy-dammarane-3β,25-diol (), 3-epi-cabraleahydroxylactone (), and cabralealactone (), were isolated from the stem bark of Miq. The Chemical structure of the new compounds was elucidated on the basis of spectroscopic data. All of the compounds were evaluated for their cytotoxic effects against MCF-7 breast cancer cells.

A new limonoid from stem bark of Chisocheton pentandrus (Meliaceae).

A new limonoid, pentandricine (1), along with three known limonoids, ceramicine B (2), 6-de(acetyloxy)-23-oxochisocheton (3), 6-de(acetyloxy)-23-oxo-7-O-deacetylchisocheton (4), have been isolated from the stembark of Chisocheton pentandrus. The chemical structures of the new compound were elucidated on the basis of spectroscopic evidence. All of the compounds were tested for their cytotoxic effects against MCF-7 breast cancer cells.

Synthetic and structure-activity relationship of insecticidal bufadienolides.

A new synthetic analog of bufadienolide, methyl isobryophyllinate A (1), and a known synthetic analog, methyl isobersaldegenate-1,3,5-orthoacetate (2), were obtained by methanolysis of bryophyllin A (3) and bersaldegenin-1,3,5-orthoacetate (5) in basic solution. Structure-insecticidal activity relationship studies revealed both orthoacetate and alpha-pyrone moieties seemed to be essential structural elements for exhibiting insecticidal activity, whereas oxygenated substituents in the C ring enhanced the insecticidal activity against the third instar larvae of silkworm (Bombyx mori).