Carbon nanotubes supported tyrosinase in the synthesis of lipophilic hydroxytyrosol and dihydrocaffeoyl catechols with antiviral activity against DNA and RNA viruses

Abstract

Hydroxytyrosol and dihydrocaffeoyl catechols with lipophilic properties have been synthesized in high yield using tyrosinase immobilized on multi-walled carbon nanotubes by the Layer-by-Layer technique. All synthesized catechols were evaluated against a large panel of DNA and RNA viruses, including Poliovirus type 1, Echovirus type 9, Herpes simplex virus type 1 (HSV-1), Herpes simplex virus type 2 (HSV-2), Coxsackievirus type B3 (Cox B3), Adenovirus type 2 and type 5 and Cytomegalovirus (CMV). A significant antiviral activity was observed in the inhibition of HSV-1, HSV-2, Cox B3 and CMV. The mechanism of action of the most active dihydrocaffeoyl derivative was investigated against a model of HSV-1 infection.

Tyrosinase mediated oxidative functionalization in the synthesis of DOPA-derived peptidomimetics with anti-Parkinson activity

“…The oxidative functionalization of BTO 1 was then performed using tyrosinase supported on multi-walled carbon nanotubes (MWCNTs) applying the Layer by Layer (LbL) procedure previously developed. 26 Briey, oxidized MWCNTs 27 were treated with a positively charged poly(diallyldimethylammonium) chloride (PDDA) to facilitate the loading of tyrosinase, that is negatively charged at the operative pH 7. Bovine Serum Albumin (BSA) was used to reduce undesired conformational changes.…”

“…29 The structural characterization and the activity parameters of catalyst MWCNT/tyrosinase/BSA (Tyr/ MWCNTs), as well as its application in the synthesis of bioactive catechol derivatives are in ref. 26. The oxidation of BTO 1 (20 mg, 0.068 mmol) with Tyro/MWCNT (600 UA) in PBS/EtOH (7 : 3 v/v, 12 mL) at 25 C for 24 h in the presence of NH 2 -Gly-OMe or N-Boc-Gly-COOH (0.68 mmol) afforded compounds 2 and 3 in 85% and 79% yield, respectively (Table 1, entries 5 and 6).…”

“…MWCNT/Tyr was prepared as previously reported. 26 Briey, PDDA coated MWCNTs in PBS were treated with a mixture of Tyr (0.2 mg) and BSA (0.6 mg) for 30 minutes. Glutaraldehyde (GA, 2.5%) was added to reach a nal volume of 800 mL and the mixture was shaken at 25 C for 30 min and at 4 C overnight.…”

Effectivity of tyrosinase purification by membrane techniques versus fractionation by salting out

“…Le Roes-Hill et al 2015); biosynthesis of antioxidants (e.g. hydroxytyrosol) (Botta et al 2015), production of prodrugs (e.g. L-DOPA) (Kampmann et al 2016) or compounds suppressing melanoma (Gąsowska-Bajger et al 2009).…”

Five New Phenolic Compounds with Antioxidant Activities from the Medicinal Insect Blaps rynchopetera

“…Our previous studies have revealed that dipeptides and phenolics—which exhibited various pharmacological activities—are the main active ingredients of this drug [ 5 ]. As part of our continuous work on the systematic study of this insect, the chemical constituents of B. rynchopetera was investigated to afford five new phenolic compounds rynchopeterines A–E ( 1 – 5 ) ( Figure 1 ), along with thirteen known phenolics, procatechuic acid ( 6 ) [ 6 ], 3,4-dihydroxyphenylacetic acid ( 7 ) [ 7 ], 3,4-dihydroxybenzaldehyde ( 8 ) [ 8 ], 3,4-dihydroxyphenylacetaldehyde ( 9 ) [ 9 ], methyl 3,4-dihydroxybenzoate ( 10 ) [ 10 ], 3,4-dihydroxyphenylacetic acid methyl ester ( 11 ) [ 11 ], 3,4-dihydroxyphenylacetic acid ethyl ester ( 12 ) [ 7 ], 2-(3,4-dihydroxyphenyl)ethanol ( 13 ) [ 12 ], 3,4-dihydroxyphenethylacetate ( 14 ) [ 13 ], blapsins A ( 15 ) and B ( 16 ) [ 14 ], 1-(3,4-dimethoxyphenyl)-4-hydroxypentan-1-one ( 17 ) [ 15 ], and 3,3′,4,4′-tetrahydroxybiphenyl ( 18 ) [ 16 ] (see Supplementary ). Herein, the isolation, structural elucidation, and bioactivity of the new compounds are described.…”