Study of alkaloids of the flora of Siberia and Altai: Synthesis of bivalent ligands of the aconitane type

Abstract

A method for N-deeH~ylalion ofditerpene alkaloids of the aconicane type by the Cope reaction was developed using conversions of lappacomthm and elatine as examples. The previously unknown hi:tones of N-deethyla~ed tappaconifine, daline, and elatidine were prepared

Hybrides of Alkaloid Lappaconitine with Pyrimidine Motif on the Anthranilic Acid Moiety: Design, Synthesis, and Investigation of Antinociceptive Potency

“…Previously, we successfully synthesized lappaconitine ynones 5, 6 by the employment of transition-metal-catalyzed cross-coupling reactions of 5 -ethynyllappaconitine 2 [39] with benzoic acid chlorides 3, 4 under Sonogashira cross-coupling reaction (Scheme 1) [38]. We observed that compounds 5 could be almost quantitatively converted into 2,4,6-trisubstituted pyrimidines 7, 8 by refluxing with acetamidine hydrochloride 9 or guanidine hydrocarbonate 10 in acetonitrile in the presence of Na 2 CO 3 (2 equivalent) with the isolated yield 81-95%.…”

“…Oxygen or water sensitive reactions were performed under the argon atmosphere. The starting material: 5 -ethynyllappaconitine 2 [39], 5 -iodolappaconitine 17 [45] and Ad 2 PBn • HBr [54,55] were synthesized, according to previously published procedures. Other reagents were purchased from commercial sources and were used without further purification.…”

Glycyrrhizic Acid as a Novel Drug Delivery Vector: Synergy of Drug Transport and Efficacy

“…4) was the second example where the participation of electron transfer stage in the process of ligand-receptor interaction was suggested and confirmed using physicochemical approach [61]. It is known that lappaconitine reveals bradycardic and hypotensive activity [64][65]. It was demonstrated using CIDNP technique, that in the presence of amino acids tyrosine and tryptophan the reaction occurs via formation of intermediate lappaconitine radical anion with following proton transfer and ether C(O)O-R bond cleavage.…”

“…This results in the drop of the product yield and, in turn, might prolong the therapeutic action of the drug. It should be mentioned that high photosensitivity of NF [64] and formation of free radical intermediates [60] [GA], mM be the reasons of high phototoxicity of nifedipine. The using of GA complexes of NF instead of free NF will results in significant decrease of toxicity of this drug, including phototoxicity (from both, reducing therapeutic dose and reducing reactivity).…”

An Efficient Access to 3,5‐Disubstituted Isoxazoles with Anthranilate Ester Moiety: Alkaloid Lappaconitine – Aryl Conjugates with an Isoxazole Linker

“…The known compound 18 [32] was involved into the cross‐coupling reaction with benzoic acid chlorides 8 a – f in the presence of a catalytic amount of Pd(PPh 3 ) 2 Cl 2 (1 mol%), CuI (2 mol%), PPh 3 (2 mol%), and Et 3 N as the base by heating in benzene (65 °C, 7 h) (TLC‐control), then the solvent was evaporated and acetonitrile, hydroxylamine hydrochloride (1.2 equiv. ), and sodium carbonate (3 equiv) (conditions i ) were added (Table 2).…”