Polycycloiridals with a Cyclopentane Ring from <i>Iris tectorum</i>

Zhang, Chunlei; Hao, Zhi‐You; Liu, Yanfei; Wang, Yan; Shi, Guo-Ru; Jiang, Zhibo; Chen, Ruo-Yun; Cao, Zhengyu; Yu, De‐Quan

doi:10.1021/acs.jnatprod.6b00796

Cited by 16 publications

(4 citation statements)

References 24 publications

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“…Furthermore, these compounds contain two E configured double bonds at Δ 14(15) and Δ 16(17) . 27 Li et al 22 reported five tricyclic iridal-type triterpenoid analogs bearing the 6/5/7-core named polycycloiridals K–O ( 60–64 ) from Belamcanda chinensis and these metabolites possess a cyclopentane core resulting via cyclization between C-18 and C-22 of the homofarnesyl chain. Moreover, these compounds illustrated weak PTP1B inhibitory effects.…”

Section: Iridal Triterpenesmentioning

confidence: 99%

Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis

et al. 2023

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Section: Iridal Triterpenesmentioning

confidence: 99%

Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis

et al. 2023

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“…Previous chemical investigations have indicated that I. tectorum Maxim. contains a range of compounds including isoflavones, 2 C ‐glycosylflavone, 3 iridal‐type triterpenoids, 4–10 lignans 11 and apocynin derivatives 12 . In addition, an HPLC‐DAD/ESI‐MS n analysis used both positive and negative ion modes to identify fourteen known flavonoids and three phenolic acids in the rhizome of I. tectorum 13 .…”

Section: Introductionmentioning

confidence: 99%

Identification and characterization of the chemical components of Iris tectorum Maxim. and evaluation of their nitric oxide inhibitory activity

Gao

Zhang

et al. 2020

Rapid Comm Mass Spectrometry

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Rationale Iris tectorum Maxim. is a traditional medicinal herb that is commonly used to treat inflammatory conditions. The present study investigated the fragmentation patterns of isoflavone glycosides and their qualitative analysis. In addition, lipopolysaccharide (LPS)‐induced RAW264.7 macrophages were used to evaluate the anti‐inflammatory properties of I. tectorum Maxim. samples collected at different time points during the year. Methods High‐performance liquid chromatography/quadrupole time‐of‐flight tandem mass spectrometry (HPLC/QTOF‐MS/MS) and HPLC with diode‐array detection were employed for qualitative and quantitative analysis. The fragmentation patterns of the isoflavones were observed in negative electrospray ionization mode with collision‐induced dissociation (CID). Their anti‐inflammatory activity was assessed via nitric oxide (NO) production in LPS‐treated RAW264.7 macrophages. Results A total of 15 chemical components were observed and tentatively identified using HPLC/QTOF‐MS/MS. At low collision energy, the relative abundances of the aglycone radical anions Y0−, [Y0 − H]−•, [Y0 − CH3]−• and [Y0 − H− CH2]−• were used for the structural characterization of tectoridin and tectorigenin‐4′‐O‐β‐D‐glucoside. The radical ions [Y0 − CH3]−• and [Y0 − H − 2CH3]−• were also employed to differentiate between iristectorin A and iristectorin B based upon their high‐energy CID spectra. Levels of 9.02 mg/g of tectoridin and 1.04 mg/g of tectorigenin were found in samples collected in June, which exhibited 69.7% NO inhibitory activity. Conclusions The characteristic fragmentation patterns enabled us to reliably identify isoflavone glycosides. The results of the quantitative determination and NO inhibitory activity offer insight into the optimal I. tectorum Maxim. harvesting time.

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“…In the past, natural product chemists used to rely on polarimetry to draw conclusions about either enantiomeric purity or AC of isolated chiral secondary metabolites [ 27 ]. Even today, however, it is not unusual to find stereochemical assignments based on comparisons of chiroptical properties (optical rotation, sometimes measured in different conditions, and/or ECD) for structurally correlated compounds [ 28 , 29 , 30 ], or even based on biosynthetic considerations [ 31 , 32 ]. It is important to mention that herein we are not questioning the referenced assignments, but rather highlighting practices that may result in misassignments.…”

Section: Introductionmentioning

confidence: 99%

Enantiomeric Mixtures in Natural Product Chemistry: Separation and Absolute Configuration Assignment

Batista

Cass

2018

Molecules

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Chiral natural product molecules are generally assumed to be biosynthesized in an enantiomerically pure or enriched fashion. Nevertheless, a significant amount of racemates or enantiomerically enriched mixtures has been reported from natural sources. This number is estimated to be even larger since the enantiomeric purity of secondary metabolites is rarely checked in the natural product isolation pipeline. This latter fact may have drastic effects on the evaluation of the biological activity of chiral natural products. A second bottleneck is the determination of their absolute configurations. Despite the widespread use of optical rotation and electronic circular dichroism, most of the stereochemical assignments are based on empirical correlations with similar compounds reported in the literature. As an alternative, the combination of vibrational circular dichroism and quantum chemical calculations has emerged as a powerful and reliable tool for both conformational and configurational analysis of natural products, even for those lacking UV-Vis chromophores. In this review, we aim to provide the reader with a critical overview of the occurrence of enantiomeric mixtures of secondary metabolites in nature as well the best practices for their detection, enantioselective separation using liquid chromatography, and determination of absolute configuration by means of vibrational circular dichroism and density functional theory calculations.

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Polycycloiridals with a Cyclopentane Ring from Iris tectorum

Cited by 16 publications

References 24 publications

Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis

Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis

Identification and characterization of the chemical components of Iris tectorum Maxim. and evaluation of their nitric oxide inhibitory activity

Enantiomeric Mixtures in Natural Product Chemistry: Separation and Absolute Configuration Assignment

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