Application of [Mo2(OAc)4] for determination of absolute configuration of brassinosteroid vic-diols by circular dichroism

Frelek, Jadwiga; Ikekawa, Nobuo; Takatsuto, Suguru; Snatzke, G�nther

doi:10.1002/(sici)1520-636x(1997)9:5/6<578::aid-chir27>3.0.co;2-k

Cited by 60 publications

(51 citation statements)

References 12 publications

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“…S17, Supporting information ). On the basis of the empirical rule proposed by Snatzke 30 , 31 , the Cotton effect indicate that the O–C–C–O torsion angle of the diol moiety in 2 is negative and also predicts 6 R ,7 R configuration. Thus, compound 2 was determined as (+)-(6 R ,7 R ,12 E )-tetradeca-12-en-10-yne-1,6,7-triol.…”

Section: Resultsmentioning

confidence: 99%

Acetylenes and fatty acids from Codonopsis pilosula

Jiang

Liu

Guo

et al. 2015

Acta Pharmaceutica Sinica B

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Four new acetylenes (1–4) and one new unsaturated ω-hydroxy fatty acid (5), together with 5 known analogues, were isolated from an aqueous extract of Codonopsis pilosula roots. Their structures were determined by spectroscopic and chemical methods. The new acetylenes are categorized as an unusual cyclotetradecatrienynone (1), tetradecenynetriol (2), and rare octenynoic acids (3 and 4), respectively, and 3 and 4 are possibly derived from oxidative metabolic degradation of 1 and/or 2. The absolute configuration of 1 was assigned by comparison of the experimental circular dichroism (CD) spectrum with the calculated electronic circular dichroism (ECD) spectra of stereoisomers based on the quantum-mechanical time-dependent density functional theory, while the configuration of 2 was assigned by using modified Mosher׳s method based on the MPA determination rule of ΔδRS values for diols.

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Section: Resultsmentioning

confidence: 99%

Acetylenes and fatty acids from Codonopsis pilosula

Jiang

Liu

Guo

et al. 2015

Acta Pharmaceutica Sinica B

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“…Compounds 5 and 6 were determined as threo and erythro configurations by the coupling constants between H-11 and H-12 ( J = 4.0 Hz for 5 ; J = 7.2 Hz for 6 ) as well as the chemical shifts of 13-methyls [ 15 , 16 ]. The absolute configuration of the 11,12-diol moieties of compounds 5 and 6 were assigned using the in situ dimolybdenum CD method developed by Snatzke and Frelek [ 17 , 18 ]. When adding dimolybdenum tetraacetate [Mo 2 (OAc) 4 ] to solution of 5 and 6 in DMSO, respectively, metal complexes were generated as an auxiliary chromophore.…”

Section: Resultsmentioning

confidence: 99%

Vibralactone Biogenesis-Associated Analogues from Submerged Cultures of the Fungus Boreostereum vibrans

Chen

Jiang

Zhao

et al. 2017

Nat. Prod. Bioprospect.

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A scale-up fermentation of the fungus Boreostereum vibrans facilitated the isolation of six new vibralactone biogenesis-associated analogues, namely vibralactamide A (1), vibralactone T (2), 13-O-lactyl vibralactone (3), 10-O-acetyl vibralactone G (4), (11R,12R)- and (11S,12R)-vibradiol (5, 6). Their structures were established via extensive spectroscopic analyses, specific optical rotation comparison, and Snatzke’s method. The biosynthetic pathway for vibralactamide A was postulated. The absolute configuration of vibralactone B was revised by single crystal X-ray diffraction analysis. This work puts the divergent vibralactone biosynthesis pathway one step further and expands the structural diversity of vibralactone-associated compounds.Graphical Abstract Electronic supplementary materialThe online version of this article (10.1007/s13659-017-0147-5) contains supplementary material, which is available to authorized users.

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“…In this case, a practical and reliable method developed by Snatzke and Frelek was employed to solve the problem. 51,52 After mixing compound 8 and dimolybdenum tetraacetate [Mo 2 (AcO) 4 ] in DMSO, a ligand-metal complex possessing an suitable chromophoric group was formed, for which the induced circular dichroism spectrum (ICD) was recorded and analyzed. According to Snatzke's theory, the absorption band around 310 nm (band IV) is one of these most reliably related to the absolute configuration of a diol derivative in the [Mo 2 (AcO) 4 ]-induced CD (ICD) spectrum, which possesses the same sign of torsional angle of the O-C-C-O unit in the favored conformation.…”

Section: Nih-pa Author Manuscriptmentioning

confidence: 99%

“…According to a published procedure, 51,52 0.3 mg of compound 8 and 0.75 mg of Mo 2 (OAc) 4 were dissolved in 1.0 mL dry DMSO to give a solution, with the ligand to metal molar ratio being around 1.0:1.2. The electronic transitions of the metal complex in DMSO was monitored by CD measurement immediately in the UV/vis region of 200 to 450 nm after mixing (recording a spectrum every 10 min), until a stationary induced circular dichrosim (ICD) spectrum was observed around 30 min later.…”

Section: Determination Of the Absolute Configuration Of The Diol Moiementioning

confidence: 99%

Bioactive Flavaglines and Other Constituents Isolated from Aglaia perviridis

Li¹,

Acuña²,

Li³

et al. 2013

Planta Med

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Eight new compounds, including two cyclopenta [b]benzopyran derivatives (1, 2), two cyclopenta [b]benzofuran derivatives (3, 4), three cycloartane triterpenoids (5-7), and an apocarotenoid (8), together with 16 known compounds, were isolated from the chloroform-soluble partitions of separate methanol extracts of a combination of the fruits leaves and twigs, and of the roots of Aglaia perviridis collected in Vietnam. Isolation work was monitored using human colon cancer cells and facilitated with an LC/MS dereplication procedure. The structures of the new compounds (1-8) were determined on the basis of spectroscopic data interpretation. The Mosher ester method was employed to determine the absolute configurations of 5-7, and the absolute configurations of the 9,10-diol unit of compound 8 was established by a dimolybdenum tetraacetate [Mo 2 (AcO) 4 ] induced circular dichroism (ICD) procedure. Seven known rocaglate derivatives (9-15) exhibited significant cytotoxicity against the HT-29 cell line, with rocaglaol (9) being the most potent (ED 50 0.0007 µM). The new compounds 2-4 were also active against this cell line, with ED 50 values ranging from 0.46 to 4.7 µM. The cytotoxic compounds were evaluated against a normal colon cell line, CCD-112CoN. In addition, the new compound perviridicin B (2), three known rocaglate derivatives (9, 11, 12), as well as a known sesquiterpene, 2-oxaisodauc-5-en-12-al (17), showed significant NF-κB (p65) inhibitory activity in an ELISA assay.* Corresponding Author. Tel: +1-614-247-8094. Fax: +1-614-247-8119. kinghorn@pharmacy.ohio-state.edu. # Dedicated to Dr. Lester A. Mitscher, of the University of Kansas, for his pioneering work on the discovery of bioactive natural products and their derivatives ASSOCIATED CONTENT Supporting Information. 1 H, 13 C and 2D NMR spectra of compounds 1-8, 1 H NMR of (R)-and (S)-MTPA esters of 5-7. This material is available free-of-charge via the Internet at http://pubs.acs.org. NIH Public AccessAuthor Manuscript J Nat Prod. Author manuscript; available in PMC 2014 March 22. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptAglaia Lour., containing more than 120 species, is the largest genus of the plant family Meliaceae. 1 Aglaia species have attracted considerable interest in the area of natural products research, since they are a rich source of the "flavagline" class of bioactive agents. Flavagline derivatives have been proposed to be biogenetically derived from the coupling of a flavonoid unit and a cinnamic acid amide moiety, and can be divided into three subtypes, namely, the cyclopenta [b]benzofurans, the cyclopenta [b]benzopyrans, and the benzo [b]oxepines. [2][3][4][5] More than 100 flavaglines have been isolated from over 30 Aglaia species to date. [2][3][4][5] In a search for new anticancer agents from tropical plants, several Aglaia species, including Aglaia crassinervia, 6 A. edulis, 7 A. elliptica, 8 A. foveolata, 9-11 A. ponapensis, 12 and A. rubiginosa, 13 mainly collected from Indonesia, have been in...

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Application of [Mo2(OAc)4] for determination of absolute configuration of brassinosteroid vic-diols by circular dichroism

Cited by 60 publications

References 12 publications

Acetylenes and fatty acids from Codonopsis pilosula

Acetylenes and fatty acids from Codonopsis pilosula

Vibralactone Biogenesis-Associated Analogues from Submerged Cultures of the Fungus Boreostereum vibrans

Bioactive Flavaglines and Other Constituents Isolated from Aglaia perviridis

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