1,4-Benzodioxane Lignans: An Efficient, Asymmetric Synthesis of Flavonolignans and Study of Neolignan Cytotoxicity and Antiviral Profiles

Abstract

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.

Synthesis and Photoswitching Properties of Bioinspired Dissymmetric γ-Pyrone, an Analogue of Cyclocurcumin

“…Finally, diynol 15 was synthesized from guaiacol ( 16 ) according to the third retrosynthetic pathway (Scheme ) via a top-down approach. After regioselective bromination with NBS (Scheme , compound 7 ) and protection of phenolic function, MOM-protected bromoguaiacol was obtained with an overall yield of 90% (Scheme , compound 17 ). − Then, Sonogashira coupling using propargyl alcohol ( 8 ) in the presence of palladium complex catalyst as well as copper cocatalyst led to butynyl alcohol derivative 18 in good yield . The oxidation with an excess of manganese dioxide gave aldehyde 19 which did not exhibit the instability of 6 . , ynal 19 could undergo the addition of 1-propynylmagnesium bromide ( 9 ) to give expected aryl-hexa-1,4-diyn-3-ol 15 with a yield of 89% .…”

Phytochemicals as Antiviral Agents: Recent Updates

“…Upon researching, it was found that this compound had the inhibitory activity against hepatitis B virus (Wang et al 2013). Furthermore, Pilkington et al (2018) isolated phytochemicals from the seeds of Silybum marianum and elucidated their antiviral activities against HCV. More recently, Rhinacanthus nasutus plant was evaluated for its use to cure fungal and herpes virus infections.…”

Synthesis and photoswitching properties of bioinspired dissymmetric gamma-pyrone, analogue of cyclocurcumin

“…After a regioselective bromination with NBS (Scheme 6, compound 7) and protection of phenolic function, the MOM protected bromoguaiacol was obtained with an overall yield of 90% (Scheme 6, compound 17). 31,32,33 Then, a Sonogashira coupling using propargyl alcohol (8) in the presence of palladium complex catalyst as well as copper co-catalyst led to butynyl alcohol derivative 18 in good yield. 34 The oxidation with an excess of manganese dioxide gave aldehyde 19 which did not exhibit the instability of 6.…”

“…To reach the photostationary state of the E®Z isomerization, the E-stereoisomer was illuminated within the p-p* band using a M375L4.1540 mW LED (LED Power Output 1540mW, 2% power used) with a central wavelength of 375 nm and a bandwidth (FWHM) of 9 nm. For the reverse transformation, Z®E isomerization, the compound was excited within the n-p* band using a M300L4 32. mW LED (LED Power Output: 47mW, full power used) with a central wavelength of 300 nm with a bandwidth (FWHM) of 20 nm.…”