Cinchona Alkaloid Derivatives modified Fe3O4 Nanoparticles for Enantioselective Ring Opening of meso- Cyclic Anhydrides

In the present work, the molecular framework of the quinidine was modified at the methoxy functional of C6’ carbon of quinoline moiety with a long-chain carboxylic acid group (-COOH) and...

Asymmetric Synthesis of Tetrasubstituted Cyclic Amines via Aza-Henry Reaction using Cinchona Alkaloid Sulfonamide/Zinc(II) Catalysts

The first enantioselective aza-Henry reaction of non-activated cyclic iminoesters, derived from cyclic amino acids, has been developed. Good yields and enantioselectivities were observed for the reaction using our original cinchona...

Genetic profiles of three Cinchona species in Junghuhn Natural Reserve, Indonesia

Cinchona species were widely used as ancient medicines for different diseases because they contain the active component quinine and its derivatives. However, studies on the molecular aspects of cinchona, including its genetic diversity, have not been reported because most previous works focused on the administration of the antimalarial cinchona alkaloid. Quinine is also being tested as alternative compound for the treatment of Covid-19. The Junghuhn Natural Reserve in Indonesia contains three different types of cinchona plants, namely, Cinchona calisaya, Cinchona pubescens, and Cinchona sp. Given that the genetic diversity and kinship of these species have never been studied, collecting data on the cinchona gene pool has become imperative. This study analyzed the genetic diversity of the cinchona species in the Junghuhn Natural Reserve, Indonesia, by using eight RAPD markers, i.e., OPA-2, OPA-9, OPB-02, OPB-03, OPB-04, OPB-05, OPB-7, and OPJ-07, during 2020 at the University of Jenderal Soedirman, Purwokerto-Indonesia. Polymorphic band data were obtained. Then, phenogram analysis was conducted by using UPGMA and maximum parsimony with MEGA7. The RAPD profiles of Cinchona species (C. calisaya, C. pubescent, and Cinchona sp.) revealed polymorphism with different markers, i.e., OPA-2 (90%), OPB-2 (75%), OPB-5 (75%), OPB-3 (66.66%), OPB-4 (66.66%), OPB-7 (66.66%), OPJ-7 (66.66%), and OPA-9 (58.33%) sequentially with total polymorphism (70.62%). C. calisaya was identified as the most distinctive species. UPGMA yielded a coefficient of 0.200 and two distinctive groups: Group I, which comprised C. pubescens and Cinchona sp. with the p-distance value of 0.333, and Group II, which contained C. calisaya. Ixora sp. was treated as an outgroup plant. The topology of the dendrogram was consistent with that of the UPGMA dendrogram. Results may be used for the further exploration of the genetic diversity of cinchona species.

Efficacy of Selenourea Organocatalysts in Asymmetric Michael Reactions under Standard and Solvent-Free Conditions

By varying the steric and electronic surroundings of the hydrogen-bonding motif, the novel chiral Cinchona-alkaloid based selenoureas were developed. Acting as bifunctional catalysts, they were applied in the Michael reactions of dithiomalonate and nitrostyrene providing chiral adducts with up to 96% ee. The asymmetric Michael–-hemiacetalization reaction of benzylidene pyruvate and dimedone, performed with the assistance of 5 mol% of selenoureas, furnished the product with up to 93% ee and excellent yields. The effectiveness of the new hydrogen-bond donors was also proved in solvent-free reactions under ball mill conditions, supporting the sustainability of the devised catalytic protocol.