Withanolide Artifacts Formed in Methanol

Cao, Cong-Mei; Zhang, Huaping; Gallagher, Robert J.; Timmermann, Barbara N.

doi:10.1021/np400296s

Cited by 25 publications

(14 citation statements)

References 30 publications

(59 reference statements)

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“…In depth analysis suggested, and subsequently proven via deuterated solvent experiments, that intramolecular ( 66 , 67 ) and intermolecular ( 16 , 22 , 68 ) Michael addition withanolide artifacts were formed from methanolic solutions of withaferin A ( 1 ), withalongolide A ( 19 ) and withalongolide B ( 20 ) (Figure 2) (Cao et al 2013). …”

Section: Withanolide Artifacts and Derivativesmentioning

confidence: 99%

Antiproliferative withanolides from several solanaceous species

Zhang

Cao

Gallagher

et al. 2014

Natural Product Research

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To date, our work on Solanaceous species (Datura wrightii, Jaborosa caulescens, Physalis hispida, P. longifolia, Vassobia breviflora, and Withania somnifera) has resulted in the isolation of 65 withanolides, 31 of which were new, as well as the semi-synthesis of a further 30 withanolides. Structure identification and MTS assay-based antiproliferative evaluation of these 95 compounds revealed that a Δ2-1-oxo functionality in ring A; in conjunction with either a 5β,6β-epoxy or 5α-chloro-6β-hydroxy moiety in ring B; are the minimum structural requirements for withanolides to produce potent cytotoxic activity. Such structural-activity relationship analysis (SARA) also revealed that oxygenation (the –OH or –OR groups) at C-4, 7, 11, and 12; as well as C-14 to C-28; did not contribute toward the observed antiproliferative activity. Herein we present a complete overview of our work as it relates to the withanolides reported from 1965 to 2013.

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Section: Withanolide Artifacts and Derivativesmentioning

confidence: 99%

Antiproliferative withanolides from several solanaceous species

Zhang

Cao

Gallagher

et al. 2014

Natural Product Research

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“…Artefacts of the isolation process are a well accepted problem. 15–17 In addition to adding some confusion to the natural products literature, the biosynthetic authenticity of a compound can be important when considering how certain compounds either support or refute a biosynthetic pathway. In this context, there is value to the development of strategies to either authenticate or invalidate isolated compounds as true secondary metabolites.…”

Section: Introductionmentioning

confidence: 99%

Prealamethicin F50 and related peptaibols from Trichoderma arundinaceum: validation of their authenticity via in situ chemical analysis

et al. 2017

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In the field of natural products chemistry, a common question pertains to the authenticity of an isolated compound, i.e. are the interesting side chains biosynthesized naturally or an artefact of the isolation/purification processes? The droplet-liquid microjunction-surface sampling probe (droplet-LMJ-SSP) coupled to a hyphenated system (UPLC-UV-HRESIMS) empowers the analysis of natural product sources in situ, providing data on the biosynthetic timing and spatial distribution of secondary metabolites. In this study the droplet-LMJ-SSP was utilized to validate the authenticity of two new peptaibols (2 and 3) as biosynthesized secondary metabolites, even though both them had structural features that could be perceived as artefacts. Compounds 2 and 3 were isolated from the scaled up fermentation of Trichoderma arundinaceum (strain MSX70741), along with a new member of the trichobrevin BIII complex (1), and four known compounds (4–7). The structures of the isolates were established using a set of spectroscopic and spectrometric methods, and their absolute configurations were determined by Marfey’s analysis. The cytotoxic activity of compounds 1, 3, 4 and 6 was evaluated against a panel of cancer cell lines, where cytotoxic activity in the single digit μM range was observed.

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“…Therefore, the structure of physanicandrolide B ( 15 ) was determined as (20 R ,22 R )-15 α- acetoxy-5β,6β-epoxy-14β,20-dihydroxy-3α-methoxy-1-oxowith-24-enolide. This compound could be an artifact produced by Michael addition of MeOH to compound 14 , however, this must be proven since the natural or artificial origin of 3-OH and 3-alkoxy withanolides is controversial. , …”

Section: Resultsmentioning

confidence: 99%

Labdanes, Withanolides, and Other Constituents from Physalis nicandroides

et al. 2019

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Chemical investigation of the aerial parts (except fruits and calixes) of Physalis nicandroides var. attenuata led to the isolation of a series of new labdane-type diterpenoids, including the closely related compounds 1−3, the labdane glucosides 4 and 5, a mixture of the epimeric alcohols 6 and 7, and one labdanetriol, isolated as its tri-Oacetyl derivative 9. In addition, three new withanolides (14− 16) and six known compounds were isolated. The structures of these compounds were elucidated by analysis of their spectroscopic data and chemical transformations, and those of compounds 1, 4, and 16 were confirmed by X-ray diffraction analysis of the natural product (1) and of the corresponding acetyl derivatives 4a and 16a. Fourteen of these compounds were assayed for their in vitro inhibitory activity against yeast αglucosidase and acetylcholinesterase enzymes. The results were negative in both cases, except for compound 3a that marginally inhibited the activity of acetylcholinesterase with an IC 50 value of 64.4 μM.

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Withanolide Artifacts Formed in Methanol

Cited by 25 publications

References 30 publications

Antiproliferative withanolides from several solanaceous species

Antiproliferative withanolides from several solanaceous species

Prealamethicin F50 and related peptaibols from Trichoderma arundinaceum: validation of their authenticity via in situ chemical analysis

Labdanes, Withanolides, and Other Constituents from Physalis nicandroides

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