Teuhetenone A

Sesquiterpenes from the Saudi Red Sea: Litophyton arboreum with their cytotoxic and antimicrobial activities.[Pubmed:29182515]

Z Naturforsch C J Biosci. 2018 Jan 26;73(1-2):9-14.

A new pseudoguaiane-type sesquiterpene named litopharbol (1) was isolated from the methanolic extract of the Red Sea soft coral Litophyton arboreum, along with known sesquiterpenoids alismol (2), alismorientol B (3), Teuhetenone A (4), and calamusin I (5); steroid, 24-methyl-cholesta-5,24(28)-diene-3beta-ol (6), alkyl glyceryl ether, chimyl alcohol (7); sphingolipid, erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8); and nitrogenous bases, thymine (9) and thymidine (10). The structures were determined on the basis of nuclear magnetic resonance (NMR) spectroscopic (1D and 2D NMR data including heteronuclear single quantum coherence spectroscopy, heteronuclear multiple-bond correlation spectroscopy, and nuclear Overhauser effect spectroscopy) and mass spectrometric analyses. Compounds 1-5 were explored for antimicrobial activity and cancer cell line sensitivity tests. Compound 1 exhibited antibacterial activity against Bacillus cereus with a minimum inhibition concentration of 1.8 mug/mL, whereas compound 3 showed significant potent cytotoxic effect against MCF-7 (breast cancer cells) with IC50 4.32 muM.

Acute Hypoglycemic and Antidiabetic Effect of Teuhetenone A Isolated from Turnera diffusa.[Pubmed:28397755]

Molecules. 2017 Apr 8;22(4):599.

Diabetes mellitus is a chronic degenerative disease that causes long-term complications and represents a serious public health problem. Turnera diffusa (damiana) is a shrub that grows throughout Mexico and is traditionally used for many illnesses including diabetes. Although a large number of plant metabolites are known, there are no reports indicating which of these are responsible for this activity, and this identification was the objective of the present work. Through bioassay-guided fractionation of a methanolic extract obtained from the aerial part of T. diffusa, Teuhetenone A was isolated and identified as the main metabolite responsible for the plant's hypoglycemic activity. Alpha-glucosidase inhibitory activity and cytotoxicity of this metabolite were determined. Hypoglycemic and antidiabetic activities were evaluated in a murine model of diabetes in vivo, by monitoring glucose levels for six hours and comparing them with levels after administering various controls. Teuhetenone A was not cytotoxic at the tested concentrations, and did not show inhibitory activity in the glucosidase test, and the in vivo assays showed a gradual reduction in glucose levels in normoglycemic and diabetic mice. Considering these results, we suggest that Teuhetenone A has potential as an antidiabetic compound, which could be further submitted to preclinical assays.

[Study on content of two sesquiterpenes in Alpinia oxyphylla].[Pubmed:23236757]

Zhongguo Zhong Yao Za Zhi. 2012 Sep;37(17):2589-93.

OBJECTIVE: To develop an HPLC method for determining oxyphyllenodiol A (1) and Teuhetenone A (2) contained in Alpinia oxyphylla and to compare the contents of the two components contained in medicinal materials and prepared herbal medicines in pieces sold in the market and different fractions. METHOD: HPLC and Waters sunfire C18 column (4. 6 mm x 250 mm, 5 microm) were adopted for gradient elute with the mobile phase of acetonitrile and water. The flow rate was 1.0 mL x min(-1) and the detection wavelength was 250 nm. RESULT: 1 and 2 showed a good linear relationship within the range of 0.1296 - 0.8640 microg and 0.1635 - 1.0900 microg respectively, with the average recoveries of 99.08% and 97.80%. Their content ranges were 0.0059% - 0.0149% and 0.0080% - 0.0164% in different samples. The mean value of 1 and 2 were 0.0085% and 0.0104% in the whole fruits, and 0.0137% and 0.0157% in the seeds. They were undetected in the nutshells. CONCLUSION: The method is so precise, accurate and highly reproducible that it can be used to determine the contents of oxyphyllenodiol A and Teuhetenone A in A. oxyphylla. The contents of the two components are mainly extracted from the seeds, with certain difference among different samples. There are a higher contents and no significant difference in the salted and raw seeds.

Terpenoid-related metabolites from a formosan soft coral Nephthea chabrolii.[Pubmed:17409554]

Chem Pharm Bull (Tokyo). 2007 Apr;55(4):594-7.

Two new sesquiterpenoidal natural products chabrolidiones A and B (1 and 2), two C(18) terpenoid-related carboxylic acids, ketochabrolic acid (3) and isoketochabrolic acid (4), and one naphthoquinone derivative chabrolonaphthoquinone C (5), along with two known compounds (+)-aristolone (6) and Teuhetenone A (7) were isolated from a Formosan soft coral Nephthea chabrolii. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis and by comparison of NMR data with those of related metabolites. Metabolite 1 has been synthesized previously, but was isolated for the first time from natural sources. Cytotoxic activity of metabolites 1-3 and 5-7 against a limited panel of cancer cell lines is also described.