Six new ent-kaurane-type diterpenoids were isolated from the leaves of the endemic Vietnamese medicinal plant Croton tonkinensis GAGNEP. (Euphorbiaceae) together with three known ent-11alpha-acetoxy-7beta,14alpha-dihydroxykaur-16-en-15-one (1), ent-kaur-16-en-15-one 18-oic acid (5) and ent-18-hydroxykaur-16-ene (7). Their structures were determined by spectroscopic analyses to be ent-7beta-acetoxy-11alpha-hydroxykaur-16-en-15-one (2), ent-18-acetoxy-11alpha-hydroxykaur-16-en-15-one (3), ent-11alpha-acetoxykaur-16-en-18-oic acid (4), ent-15alpha,18-dihydroxykaur-16-ene (6), ent-11alpha,18-diacetoxy-7beta-hydroxykaur-16-en-15-one (8), and ent-(16S)-1alpha,14alpha-diacetoxy-7beta-hydroxy-17-methoxykauran-15-one (14). ent-Kaurane-type diterpenoids from Croton tonkinensis 2-4, 6, and 9-13, were tested for toxicity in the brine shrimp lethality assay. Compounds 9, 10, and 12 demonstrated significant activity, compounds 2, 3, 6, and 11 showed weak activity, and compounds 4 and 13 were inactive.
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http://dx.doi.org/10.1248/cpb.53.296 | DOI Listing |
Int J Mol Sci
November 2024
Department of Thoracic Surgery, Mackay Memorial Hospital, Taipei 104, Taiwan.
Radiotherapy combined with a radiosensitizer represents an important treatment for head and neck squamous cell carcinoma (HNSCC). Only a few chemotherapy agents are currently approved as radiosensitizers for targeted therapy. Oral squamous cell carcinoma is one of the deadliest cancers, with approximately ~500,000 new diagnosed cases and 145,000 deaths worldwide per year.
View Article and Find Full Text PDFBiomedicines
August 2023
School of Medicine, National Sun Yat Sen University College of Medicine, Kaohsiung 804, Taiwan.
The hyperpolarization-activated cation current () exhibits a slowly activating time course of the current () when the cell membrane is hyperpolarized for an extended duration. It is involved in generating electrical activity in various excitable cells. Numerous structurally distinct compounds or herbal drugs have the potential to impact both the magnitude and gating kinetics of this current.
View Article and Find Full Text PDFInt J Mol Sci
February 2020
Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan.
Unlabelled: Croton is an extensive flowering plant genus in the spurge family, Euphorbiaceae. Three croton compounds with the common ent-kaurane skeleton have been purified from roton tonkinensis.
Methods: We examined any modifications of croton components (i.
Eur J Pharmacol
August 2019
Department of Physiology, National Cheng Kung University Medical College, Tainan City, Taiwan; Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, Taiwan. Electronic address:
Croton is an extensive flowering plant genus in the spurge family, Euphorbiaceae. Three croton compounds with the common ent-kaurane skeleton were purified from Croton tonkinensis. By using patch-clamp recording technique, we thoroughly examined the effect of a group of croton compounds, croton-01 (ent-18-acetoxy-7α-hydroxykaur-16-en-15-one), croton-02 (ent-7α,14β-dihydroxykaur-16-en-15-one), and croton-03 (ent-1β-acetoxy-7α,14β-dihydroxykaur-16-en-15-one), on the membrane current in SM826 and BV2 microglial cells.
View Article and Find Full Text PDFFundam Clin Pharmacol
April 2016
Faculté des Sciences Pharmaceutiques, UPS, UMR 152 Pharma-DEV, Université de Toulouse, Université Toulouse 3, 35 Chemin des Maraîchers, Toulouse Cedex 9, F-31062, France.
Human hepatocellular carcinoma (HCC) is the most common type of liver cancer, the second most common cause of death from cancer worldwide. A very poor prognosis and a lack of effective treatments make liver cancer a major public health problem, notably in less developed regions, particularly in eastern Asia. This fully justifies the search of new molecules and therapeutic strategies against HCC.
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