Synthesis of Cardiotonic Steroids Oleandrigenin and Rhodexin B

This article describes a concise synthesis of cardiotonic steroids oleandrigenin (7) and its subsequent elaboration into the natural product rhodexin B (2) from the readily available intermediate (8) that could be derived from the commercially available steroids testosterone or DHEA via 3 step sequences. These studies feature an expedient installation of the β16-oxidation based on β14-hydroxyl directed epoxidation and subsequent epoxide rearrangement. The following singlet oxygen oxidation of the C17 furan moiety provides access to oleandrigenin (7) in 12 steps (LLS) and 3.9% overall yield from 8. The synthetic oleandrigenin (7) was successfully glycosylated with L-rhamnopyranoside-based donor using Pd(II)-catalyst, and the subsequent deprotection under acidic conditions provided cytotoxic natural product rhodexin B (2) in 68% yield (2 steps). <br>

Synthesis of Cardiotonic Steroids Oleandrigenin and Rhodexin B

This article describes a concise synthesis of cardiotonic steroids oleandrigenin (7) and its subsequent elaboration into the natural product rhodexin B (2) from the readily available intermediate (8) that could be derived from the commercially available steroids testosterone or DHEA via 3 step sequences. These studies feature an expedient installation of the β16-oxidation based on β14-hydroxyl directed epoxidation and subsequent epoxide rearrangement. The following singlet oxygen oxidation of the C17 furan moiety provides access to oleandrigenin (7) in 12 steps (LLS) and 3.9% overall yield from 8. The synthetic oleandrigenin (7) was successfully glycosylated with L-rhamnopyranoside-based donor using Pd(II)-catalyst, and the subsequent deprotection under acidic conditions provided cytotoxic natural product rhodexin B (2) in 68% yield (2 steps). <br>

QSAR and docking studies of 3, 5-dimethylpyrazole as potent inhibitors of Phosphodiesterase-4

A quantitative structure-activity relationship (QSAR) study was performed to develop a model on a series of 3, 5-dimethylpyrazole containing furan moiety derivatives which exhibited considerable inhibitory activity against PDE4B. The obtained model has correlation coefficient (r) of 0.934, squared correlation coefficient (r2) of 0.872, and leave-one-out (LOO) cross-validation coefficient (Q2) value of 0.733. The predictive power of the developed model was confirmed by the external validation which has (r2) value of 0.812. These parameters confirm the stability and robustness of the model to predict the activity of a new designed set of 3,5-dimethyl-pyrazole derivatives (I-XV), results indicated that the compound III, V, XIII, and XV showed the strongest inhibition activity (IC50 = 0.2813, 0.5814, 0.6929, 0.6125μM, respectively) against PDE4B compared to the reference rolipram with (IC50=1.9μM). Molecular docking was performed on a new designed compound with PDE4B protein (3o0j). Docking results showed that compounds (X and IX) have high docking affinity of -36.2037 and -33.2888 kcal/mol respectively. Keywords: QSAR, molecular docking, pyrazole derivatives, PDE4 inhibitors, anti-inflammatory.

MCF-7 Human Breast Adenocarcinoma Anticancer and Antimicrobial, in silico Docking and ADME Prediction Studies of Furan Moiety Containing Substituted 2-Aminopyrimidine Derivatives

A series of 4(5-(4-chlorophenyl)furan-2-yl)-6-phenylpyrimidin-2-amine derivatives (5a-h) were synthesized from 2-(4-chlorophenyl)-5-styrylfuran (3a-h) with guanidine nitrate in absolute ethanol under conventional method and evaluated for their in vitro anticancer, antimicrobial activities and in silico studies. The chemical structure of the furan moiety containing substituted amino pyrimidine derivatives (5a-h) were elucidated from spectroscopic analysis like infrared, 1H & 13C NMR spectral data and CHN analysis. in silico docking studies were predicted for the synthesized compounds (5a-h) using bacterial protein 1UAG and in silico ADME predictions were also carried for the synthesized compounds (5a-h). The in vitro anticancer study was carried the compound 5b by MMT assay. Compound 5b shows the LC50 value of 120.15 ± 0.003 μg/mL. in vitro Antimicrobial activities were screened for the compounds (5a-h) using different strains. Compound 5h has electron withdrawing group in benzene ring substituted in the para position showed good antimicrobial activity against all the bacterial strains and fungal strains. in silico studies, compound 5h shows excellent docking score (-9.7 kcal/mol) compared with ciprofloxacin (-7.8 kcal/mol).

Recent advances in the Silver catalysed synthesis of furan and its applications

: Furan and its derivatives find wide-spread application as pharmaceuticals, pigments, dyes, brighteners, flavour & fragrance compounds and insecticides. They also exhibit anti-hyperglycemic, analgesic, anti-inflammatory, antibacterial, anti-fungal and anti-tumour activities. Silver catalysts are nowadays commonly used in organic synthesis due to the high oxidation potential and versatile nature of silver complexes. In this review, we summarise the recent advances in the synthesis and applications of furan moiety using silver catalysis and covers literature from 2015-2020.

Visible-Light Triggered Templated Ligation on Surface Using Furan-Modified PNAs

Oligonucleotide-templated reactions are frequently exploited for target detection in biosensors and for the construction of DNA-based materials and probes in nanotechnology. Translation of the specifically used template chemistry from solution to surfaces, with the final aim of achieving highly selective high-throughput systems, has been difficult to reach and poorly explored. Here, we show the first example of a visible light-triggered templated ligation on a surface, employing furan-modified peptide nucleic acids (PNAs). Tailored photo-oxidation of the pro-reactive furan moiety is ensured by the simultaneous introduction of a weak photosensitizer as well as a nucleophilic moiety in the reacting PNA strand. This allows a localized production of singlet oxygen for furan activation, which is not affected by probe dilution or reducing conditions. White light irradiation in combination with recognition of a short 22mer oligo sequence that functions as a template, allows sensitive detection of nucleic acid targets in a 96 well plate format.

Visible-Light Triggered Templated Ligation on Surface Using Furan-Modified PNAs

Oligonucleotide-templated reactions are frequently exploited for target detection in biosensors and for the construction of DNA-based materials and probes in nanotechnology. Translation of the specifically used template chemistry from solution to surfaces, with the final aim of achieving highly selective high-throughput systems, has been difficult to reach and poorly explored. Here, we show the first example of a visible light-triggered templated ligation on a surface, employing furan-modified peptide nucleic acids (PNAs). Tailored photo-oxidation of the pro-reactive furan moiety is ensured by the simultaneous introduction of a weak photosensitizer as well as a nucleophilic moiety in the reacting PNA strand. This allows a localized production of singlet oxygen for furan activation, which is not affected by probe dilution or reducing conditions. White light irradiation in combination with recognition of a short 22mer oligo sequence that functions as a template, allows sensitive detection of nucleic acid targets in a 96 well plate format.