Alkaloids from plants of the genus Nitraria

Abstract

Acetylkomaroidine (1c). Fractions 8-15 were combined. Solvent was distilled off. The residual was crystallized from ethanol:acetone to afford 1c (34 mg), mp 229-230°C.Extraction and separation of the total bases from N. komarovii has been described in detail [8,9]. The benzene part of the total bases was separated by chromatography over a silica-gel column with elution by CHCl 3 :CH 3 OH (20:1, 10:1, 4:1). Fractions (15-20 mL) were collected.Komaroidine (1b). Fractions 14-16 were combined and separated by chromatography over a silica-gel column with elution by CHCl 3 :CH 3 OH (10:1). Fractions (8-10 mL) were collected. Fractions 17-23 were combined and worked up by crystallization from ethanol:acetone to afford 1b (56 mg), mp 207-208°C.Acetylkomaroidine (1c). Fractions 11-16 were combined and worked up by crystallization from ethanol:acetone to afford 1c (51 mg), mp 229-230°C.Hydrolysis of 1c. Komaroidine. Base 1c (0.05 g) was dissolved in HCl (5 mL, 1 N) and heated at 90°C for 2 h. After the reaction was complete, the solution was cooled, made basic with KOH solution (10%), and extracted with CHCl 3 . Solvent was distilled off. The residual was crystallized from acetone:ethanol to afford komaroidine (0.027 g), mp 207-208°C.Acetylation of Komaroidine (Acetylkomaroidine). A mixture of 1b (0.04 g), pyridine (1 mL), and acetic anhydride (1 mL) was left at room temperature for 5 d. After the reaction was complete, the excesses of anhdyride and pyridine were removed in vacuo. The dry residual was treated with water (2 mL) and made basic with conc. aqueous NH 3 . The product was extracted with ether. The ether extract was dried over anhydrous Na 2 SO 4 . Solvent was distilled off. The residual was crystallized from acetone:ethanol to afford N-acetylkomaroidine (0.031 g), mp 229-230°C.Synthesis of Komaroidine. A mixture of tryptamine hydrochloride (1 g, 0.005 mol) in water (15 mL), ethanol (25 mL), H 2 SO 4 (3 mL, 2 N), and butyraldehyde (3 mL) was gradually heated to boiling on a sand bath and held at this temperature for 5 h. The alcohol was distilled off in vacuo. The solution was made basic with conc. aqueous NH 3 . The product was extracted with CHCl 3 . The CHCl 3 was distilled off. The solid was crystallized from acetone:alcohol to afford 1b (0.91 g), mp 207-208°C.Synthesis of Schobericine. Schobericine was synthesized by condensation of serotonin and butyraldehyde by the method described above for the synthesis of komaroidine to afford 1a (0.87 g), mp 193-194°C.

Recent Advances in the Synthesis of β-Carboline Alkaloids

“…The role of H2O2 is to speed up the reaction by the oxidation of DMS back into DMSO. Intermediates 116 and 117 could then be transformed into eudistiomin U (10) or kumujian C (16) Szabó et al have recently published the first total synthesis of alkaloids trigonostemine A, B and G (17)(18)(19) and the preparation of pityriacitrin (20) and hyrtiosulawesine (21) (Scheme 10) [123,124]. The appropriate key intermediates kumujian C (16) and its derivatives (132,133) were prepared via a novel and practical synthesis route.…”

“…Finally, oxidation of the hydroxy group in alcohols 129-131 was achieved using MnO2 on Celite ® , and aldehydes 16, 132, 133 were isolated in good yields. The synthesis of alkaloids 17-21 was then performed from these building blocks (16,132,133), which were reacted with indoles (134)(135)(136)(137) to afford secondary alcohols and then oxidized with active MnO2 to provide the first total synthesis of trigonostemines A (17) and B (18), carried out in 7 steps. At the same time, this pathway represents a new synthetic method for the preparation of pityriacitrin (20).…”

“…-B inhibitor11] (−)-tetrahydroharman/ (S)-eleagnine (−)-komaroidine N-(+)-methyltetrahydro-harman (+)-1-ethyl-9-methyl-tetrahydro-βcarboline (+)-N-acetyl-komarodine 2: R 1 , R 3 = H, R 2 = Me; 3: R 1 , R 3 = H, R 2 = Pr; 4: R 1 , R 2 = Me, R 3 = H; 5: R 1 = Me, R 2 = Et, R 3 = H; 6: R 1 = H, R 2 = Pr, R 3 = Ac; Albizia polyphylla[17] 3, 6: N. komarovii and N. schoberi[18] Petalostyles labicheoides[19] analogues of natural prod-…”

Biochemical profile and bioactive potential of thirteen wild folk medicinal plants from Balochistan, Pakistan

“…The selection of the plants was based on ethnobotanical appraisal of local communities, their uses in folk medicines to cure various ailments like fever, cough, inflammation of organs, gonorrhea, urinary tract infection (UTI), diabetes, cancer, etc. the previously secondary metabolites such as flavonoids and alkaloids derivatives were evaluated in Zygophyllaceae [69,70].…”

Enzyme-catalyzed kinetic resolution and heterogeneous metal-catalyzed racemization of 1-substituted tetrahydroisoquinoline and tetrahydro-ß-carboline derivatives

“…69 Komaroidine [(±)-7] was isolated from Nitraria species. 70 The protected form of (S)-1-isopropyl-1,2,3,4-tetrahydro-ß-carboline [(S)-9] was used in the synthesis of (S)-quinolactacin-B (Figure 3) by the Winterfeldt reaction. The latter compound shows activity against tumor necrosis factor.…”