Theoretical and experimental study of aparisthman: A natural product with anti‐ulcer activity

Int J of Quantum Chemistry

Alves

et al. 2007

Julocrotine,forms of Leishmania amazonensis (L.). In this work, the crystal structure of Julocrotine was solved by X-ray diffraction, and its geometrical parameters were compared with theoretical calculations at the B3LYP and HF level of theory. IR and NMR spectra also have been obtained and compared with theoretical calculations. IR absorptions calculated with the B3LYP level of theory employed together with the 6-311Gϩ(d,p) basis set, are close to those observed experimentally. Theoretical NMR calculations show little deviation from experimental results. The results show that the theory is in accordance with the experimental data.

Section: Resultssupporting

confidence: 91%

Crystal structure and theoretical calculations of Julocrotine, a natural product with antileishmanial activity

Moreira

Int J of Quantum Chemistry

Alves

et al. 2007

“…Baill. yielded mainly two furan diterpenes with clerodane skeleton, aparisthman and cordatin 1–5. These compounds show significant antiulcerogenic activity comparable to cimetidine (Tagamet®), a compound used for the treatment of peptic ulcers 3, 4.…”

Section: Introductionmentioning

confidence: 99%

“…Several works have been written comparing the experimental data of NMR spectroscopy with theoretical calculations by several methods. Works involving comparisons of experimental and theoretical data are found to aparisthman 5, strychnine 6, corianlactone 6, daphnipaxinin 6, boletunone B 6, julocrotine 7, and others. Other studies comparing theoretical and experimental data, involving the NMR experiments of 17 O have been related in the literature 8.…”

Section: Introductionmentioning

confidence: 99%

Crystal structure and theoretical study of IR and ¹H and ¹³C NMR spectra of cordatin, a natural product with antiulcerogenic activity

Int J of Quantum Chemistry

Alves

Guilhon

et al. 2008

Registro de acceso restringido Este recurso no está disponible en acceso abierto por política de la editorial. No obstante, se puede acceder al texto completo desde la Universitat Jaume I o si el usuario cuenta con suscripción. Registre d'accés restringit Aquest recurs no està disponible en accés obert per política de l'editorial. No obstant això, es pot accedir al text complet des de la Universitat Jaume I o si l'usuari compta amb subscripció. Restricted access item This item isn't open access because of publisher's policy. The full--text version is only available from Jaume I University or if the user has a running suscription to the publisher's contents.

“…Similar methods involving comparison of experimental and theoretical NMR data have been reported for aparisthman, 36 strychnine, 37 The geometry obtained from X-ray diffraction data of 2 was used as input for the full geometry optimization. This molecular conformation was optimized using the B3LYP hybrid functional, 39 together with the 6-31G(d,p) basis in the Gaussian 03 molecular package.…”

Section: Methodsmentioning

confidence: 99%

Isolation, X-ray crystal structure and theoretical calculations of the new compound 8-Eepicordatin and identification of others terpenes and steroids from the bark and leaves of Croton palanostigma Klotzsch

Müller

Guilhon

et al. 2010

J. Braz. Chem. Soc.

Estudos fitoquímicos com as cascas do caule e com as folhas de Croton palanostigma Klotzsch (Euphorbiaceae) levaram ao isolamento do novo diterpeno clerodânico 8-epicordatina (2), além de éster metílico do ácido 12-oxohardwickiico (3), aparisthmano, cordatina (1), ácido ent-trachiloban-18-óico, óxido de ent-13-epimanoila, óxido de ent-3-oxo-13-epimanoila, óxido de ent-3β-hidroxi-13-epimanoila, sitosterol, estigmasterol, estigmastan-3-ona, 6β-hidroxiestigmast-4-en-3-ona, 6b-hidroxiestigmasta-4,22-dien-3-ona, estigmast-4-en-3-ona, estigmasta-4,22-dien-3-ona, ácido 3-O-acetilaleuritolico, 11a-hidroxiurs-12-en-3-ona, a-amirenona, 24-metilenocicloartenona e lupenona. Estas substâncias foram isoladas através de procedimentos fitoquímicos usuais e suas estruturas foram deduzidas por estudos espectroscópicos, incluindo experimentos em 2D. Adicionalmente, a estrutura cristalina de 8-epicordatina (2) foi determinada por difração de raios-X. Cálculos teóricos de RMN ao nível B3PW91/DGDZVP foram usados para confirmação dos assinalamentos dos deslocamentos químicos dos hidrogênios H-7a e H-7β de 8-epicordatina.Phytochemical studies of the bark and leaves of Croton palanostigma Klotzsch (Euphorbiaceae) led to the isolation of a new clerodane diterpene, 8-epicordatin (2), in addition to 12-oxohardwickiic acid methyl ester (3), aparisthman, cordatin (1), ent-trachyloban-18-oic acid, ent-13-epimanoyl oxide, ent-3-oxo-13-epimanoyl oxide, ent-3b-hydroxy-13-epimanoyl oxide, sitosterol, stigmasterol, stigmastan-3-one, 6b-hydroxystigmast-4-en-3-one, 6b-hydroxystigmasta-4,22-dien-3-one, stigmast-4-en-3-one, stigmasta-4,22-dien-3-one, 3-O-acetylaleuritolic acid, 11a-hydroxyurs-12-en-3-one, a-amyrenone, 24-methylenecycloartenone and lupenone. These compounds were isolated using typical phytochemical procedures and the structures were deduced from spectroscopic studies, including 2D NMR experiments. In addition, the crystalline structure of 8-epicordatin (2) was determined by X-ray diffraction. NMR theoretical calculations at the B3PW91/DGDZVP level were used to confirm the assignment of the chemical shifts of the H-7a and H-7b hydrogens of 8-epicordatin.