Kaurenoic acid (KA), a kaurane-type diterpene extracted from leaves of Mikania hirsutissima, was previously reported as an inhibitor of vascular contractility mainly by blocking extracellular Ca2+ influx. The compound...Kaurenoic acid (KA), a kaurane-type diterpene extracted from leaves of Mikania hirsutissima, was previously reported as an inhibitor of vascular contractility mainly by blocking extracellular Ca2+ influx. The compound is known for several other biological activities such as antiparasitic, antispasmodic and antibacterial activity. The aim of the present study was to investigate the effect of KA on Aspergillus nidulans. KA (0.3 mM) showed fungistatic activity against A. nidulans with visible hyphal elongation and morphology damage. These effects were reverted by CaCl2 addition showing that KA interferes with intracellular Ca2+ gradient in A. nidulans. This is the first report on the mechanism of action of KA involving calcium levels by altering the elongation of fungi hyphae.展开更多
The kaurenoic acid-type diterpenoids in Acanthopanacis Cortex have been reported to be the major active components. However, the diterpenoids are present as position isomers that exacerbate the challenges in obtaining...The kaurenoic acid-type diterpenoids in Acanthopanacis Cortex have been reported to be the major active components. However, the diterpenoids are present as position isomers that exacerbate the challenges in obtaining standards compounds. Little work has been done on the quantitative analysis of the diterpenoids in the herb. In the present study, two diterpenoid isomers ent-16βH,17-isovalerate-kauran-19-oic acid(1) and ent-16βH,17-methyl butanoate-kauran-19-oic acid(2) with high purity were separated by analytical HPLC, followed by recrystallization in acetone. Furthermore, an HPLC-ELSD method was developed and validated for simultaneous determination of 1 and 2 in 9 batches of Acanthopanacis Cortex samples. The HPLC separation and quantification was achieved in 40 min using an Agela Promosil C18 column eluted with a gradient of water and acetonitrile. The calibration curves showed good linearity(r^2 ≥ 0.999 9) within the test ranges. The LOD ranged from 0.407 2 to 0.518 0 mg and LOQ ranged from 1.018 0 to 1.295 0 mg. The precisions(%RSD) were within 1.47% for the two isomers. The recovery of the assay was in the range of 98.78%-99.11% with RSD values less than 2.76%. It is the first time to establish a quantitative HPLC method for the analysis of the bioactive kaurenoic acid isomers in the herb.展开更多
基金J.A.R.received a Doctoral Fellowship from Coorde-nacao de Apoio de Pessoal de Nível Superio(CAPES)N.S.A.would like to thank Universidade Estadual de Londrina and Fundacao Araucária.
文摘Kaurenoic acid (KA), a kaurane-type diterpene extracted from leaves of Mikania hirsutissima, was previously reported as an inhibitor of vascular contractility mainly by blocking extracellular Ca2+ influx. The compound is known for several other biological activities such as antiparasitic, antispasmodic and antibacterial activity. The aim of the present study was to investigate the effect of KA on Aspergillus nidulans. KA (0.3 mM) showed fungistatic activity against A. nidulans with visible hyphal elongation and morphology damage. These effects were reverted by CaCl2 addition showing that KA interferes with intracellular Ca2+ gradient in A. nidulans. This is the first report on the mechanism of action of KA involving calcium levels by altering the elongation of fungi hyphae.
基金supported by a grant from Chinese Pharmacopoeia Commission(No.2010-385)
文摘The kaurenoic acid-type diterpenoids in Acanthopanacis Cortex have been reported to be the major active components. However, the diterpenoids are present as position isomers that exacerbate the challenges in obtaining standards compounds. Little work has been done on the quantitative analysis of the diterpenoids in the herb. In the present study, two diterpenoid isomers ent-16βH,17-isovalerate-kauran-19-oic acid(1) and ent-16βH,17-methyl butanoate-kauran-19-oic acid(2) with high purity were separated by analytical HPLC, followed by recrystallization in acetone. Furthermore, an HPLC-ELSD method was developed and validated for simultaneous determination of 1 and 2 in 9 batches of Acanthopanacis Cortex samples. The HPLC separation and quantification was achieved in 40 min using an Agela Promosil C18 column eluted with a gradient of water and acetonitrile. The calibration curves showed good linearity(r^2 ≥ 0.999 9) within the test ranges. The LOD ranged from 0.407 2 to 0.518 0 mg and LOQ ranged from 1.018 0 to 1.295 0 mg. The precisions(%RSD) were within 1.47% for the two isomers. The recovery of the assay was in the range of 98.78%-99.11% with RSD values less than 2.76%. It is the first time to establish a quantitative HPLC method for the analysis of the bioactive kaurenoic acid isomers in the herb.
