The enantioselective total synthesis of the biologically active 1,4‐benzodioxane lignans isoamericanin A (2) and isoamericanol A (3) has been achieved in 11 and 12 steps, respectively. These benzodioxane lignan natural products, and others that contain 9‐hydroxymethyl group, show a wide range of biological properties. The 1,4‐benzodioxane ring was formed by an acid‐catalysed cyclisation, which gave the desired trans isomer exclusively. This method will allow the synthesis of a number of benzodioxane compounds containing a 9‐hydroxymethyl group

The enantioselective synthesis of (-)-eusiderins A (1), B (2), G (25), L (23), M (5) and (+)-eusiderin C (20) and a range of analogues was undertaken using an efficient, divergent synthesis all from a single chiral aldehyde 15, which was derived from (S)-ethyl lactate 9. A comprehensive set of NMR data along with ECD spectra and optical rotation measurements of the synthesized natural products and analogues were then obtained. This data confirmed the absolute stereochemistry of eusiderins A (1) and C (20) and for the first time gives the ECD and optical rotation for eusiderins B (2), G (25), L (23), and M (5) and a range of other substituted 1,4-benzodioxanes. This data will now allow for the determination of absolute stereochemistry of other members in this class of compound.

Biological thiols (biothiols) in cells and bodily fluids are intrinsically linked to the functioning of important enzymes, deficiency in which can lead to a wide range of physiological and pathological...

Lignan-derived 1,4-benzodioxane natural products have been shown to exhibit a diverse array of biological activities, which has lent them to be the focus of a wealth of synthetic attention. Herein we review the background, bioactivities, biosynthesis and synthetic approaches to the 1,4-benzodioxane lignan scaffold, with an emphasis on 1,4-benzodioxane oxyneolignans.

The thieno[2,3-b]pyridines bind to TDP1 with the best analogue 9d with IC50 at 0.5 μM.

The COVID-19 pandemic led to an abrupt suspension of face-to-face teaching activities in higher education institutions across the globe. The instructors and faculty at most institutions have had to adapt, invent, and implement adjustments quickly to adopt an online learning environment. This has been an extraordinarily challenging time for both students and

In an effort to gain more understanding on the structure activity relationship of pseudoceratidine 1, a di-bromo pyrrole spermidine alkaloid derived from the marine sponge Pseudoceratina purpurea that has been shown to exhibit potent biofouling, anti-fungal, antibacterial, and anti-malarial activities, a large series of 65 compounds that incorporated several aspects of structural variation has been synthesised through an efficient, divergent method that allowed for a number of analogues to be generated from common precursors. Subsequently, all analogues were assessed for their antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Overall, several compounds exhibited comparable or better activity than that of pseudoceratidine 1, and it was found that this class of compounds is generally more effective against Gram-positive than Gram-negative bacteria. Furthermore, altering several structural features allowed for the establishment of a comprehensive structure activity relationship (SAR), where it was concluded that several structural features are critical for potent anti-bacterial activity, including di-halogenation (preferable bromine, but chlorine is also effective) on the pyrrole ring, two pyrrolic units in the structure and with one or more secondary amines in the chain adjoining these units, with longer chains giving rise to better activities.

1,4-Benzodioxane lignans are a class of bioactive compounds that have received much attention through the years. Herein research pertaining to both 1,4-benzodioxane flavonolignans and 1,4-benzodioxane neolignans is presented. A novel synthesis of both traditional 1,4-benzodioxane flavonolignans and 3-deoxyflavonolignans is described. The antiviral and cytotoxic activities of 1,4-benzodioxane neolignans were then investigated; eusiderins A, B, G, and M, deallyl eusiderin A, and nitidanin, which contain the 1,4-benzodioxane motif but lack the chromanone motif found in the known antiviral flavonolignans, were tested. Notably, it was found that all eusiderin 1,4-benzodioxane neolignans exhibited greater antiviral activity than the potent and well-known silybin flavonolignans. While most modifications of the C-1′ side chain did not significantly alter the cytotoxicity or antiviral activity, eusiderin M and nitidanin, which contain an allylic alcohol side chain, had lower cytotoxicity. All the eusiderins had similar antiviral activities, with eusiderin B having the best selectivity index. These results show that the chromanone moiety of the flavonolignans is not essential for bioactivity.