Unified Synthesis of Polycyclic Alkaloids via Complementary Carbonyl Activation

A complementary dual carbonyl activation strategy for the<br>synthesis of polycyclic alkaloids has been developed. Successful applications include the synthesis of tetracyclic alkaloids harmalanine, harmalacinine, pentacyclic indoloquinolizidine alkaloid nortetoyobyrine, and octacyclic β-carboline alkaloid peganumine A. The latter synthesis features a protecting-group-free assembly and an asymmetric disulfonimide catalyzed cyclization. Furthermore, formal syntheses of hirsutine, deplancheine, 10-desbromoarborescidine A, and oxindole alkaloids rhynchophylline and isorhynchophylline have been achieved. Finally, a concise synthesis of berberine alkaloid ilicifoline B was completed.

Unified Synthesis of Polycyclic Alkaloids via Complementary Carbonyl Activation

A complementary dual carbonyl activation strategy for the<br>synthesis of polycyclic alkaloids has been developed. Successful applications include the synthesis of tetracyclic alkaloids harmalanine, harmalacinine, pentacyclic indoloquinolizidine alkaloid nortetoyobyrine, and octacyclic β-carboline alkaloid peganumine A. The latter synthesis features a protecting-group-free assembly and an asymmetric disulfonimide catalyzed cyclization. Furthermore, formal syntheses of hirsutine, deplancheine, 10-desbromoarborescidine A, and oxindole alkaloids rhynchophylline and isorhynchophylline have been achieved. Finally, a concise synthesis of berberine alkaloid ilicifoline B was completed.

Yellow Medicine of Nature- The future Chartbuster Protoberberine Antivirals

Emerging viral diseases are one of the principal threat towards the plants, animals and humans. Viruses are fast evolving, resulting in reduced effectiveness of existing drugs and vaccines. At this juncture, the importance of traditional medicine, as well as medicinal plant active principles, occupies central attention of researchers across the world. Protoberberine alkaloids, an essential group of isoquinoline family of alkaloids, exhibit properties were affecting the life cycle of DNA and RNA viruses. However, from this protoberberine group, only berberine alkaloid has been studied in detail for its mechanism of action. Berberine is useful both in the case of enveloped and non-enveloped viruses. Berberine inhibits viral life cycle by modulating NF-kB signalling, targeting viral glycoproteins and downregulation of MEK-ERK signalling. Apart from this, berberine also inhibits ACE. All protoberberine alkaloids share a characteristic protoberberine skeleton. The protoberberine containing botanicals also exhibited antiviral properties. Therefore protoberberine alkaloids and protoberberine containing botanicals are interesting to experiment in detail for their antiviral properties and mechanism of action in emerging viral diseases of plants, animals and humans.