Powerful GC-TOF-MS Techniques for Screening, Identification and Quantification of Halogenated Natural Products

In Traditional Chinese Medicine (TCM), Mori ramulus (Chin.Ph.)—the dried twigs of Morus alba L.—is extensively used as an antirheumatic agent and also finds additional use in asthma therapy. As a pathological high xanthine oxidase (XO, EC 1.1.3.22) activity is strongly correlated to hyperuricemy and gout, standard anti-hyperuremic therapy typically involves XO inhibitors like allopurinol, which often cause adverse effects by inhibiting other enzymes involved in purine metabolism. Mori ramulus may therefore be a promissing source for the development of new antirheumatic therapeutics with less side effects. Coumarins, one of the dominant groups of bioactive constituents of M. alba, have been demonstrated to possess anti-inflammatory, antiplatelet aggregation, antitumor, and acetylcholinesterase (AChE) inhibitory activities. The combination of HPLC (DAD) and Q-TOF technique could give excellent separating and good structural characterization abilities which make it suitable to analyze complex multi-herbal extracts in TCM. The aim of this study was to develop a HPLC (DAD)/ESI-Q-TOF-MS/MS method for the identification and profiling of pharmacologically active coumarin glycosides in Mori ramulus refined extracts for used in TCM. This HPLC (DAD)/ESI-Q-TOF-MS/MS method provided a rapid and accurate method for identification of coumarin glycosides—including new natural products described here for the first time—in the crude extract of M. alba L. In the course of this project, two novel natural products moriramulosid A (umbelliferone-6-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside) and moriramulosid B (6-[[6-O-(6-deoxy-α-l-mannopyranosyl)-β-d-glucopyranosyl]oxy]-2H-1-benzopyran-1-one) were newly discovered and the known natural product Scopolin was identified in M. alba L. for the first time.

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Will Climate Change Influence Production and Environmental Pathways of Halogenated Natural Products?

Environmental Science & Technology ◽

10.1021/acs.est.9b07709 ◽

2020 ◽

Vol 54 (11) ◽

pp. 6468-6485 ◽

Cited By ~ 4

Author(s):

Terry F. Bidleman ◽

Agneta Andersson ◽

Peter Haglund ◽

Mats Tysklind

Keyword(s):

Climate Change ◽

Natural Products ◽

Halogenated Natural Products

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Halonium-Induced Polyene Cyclizations

Synthesis ◽

10.1055/s-0037-1612254 ◽

2019 ◽

Vol 51 (08) ◽

pp. 1753-1769 ◽

Cited By ~ 7

Author(s):

Agathe D’Hollander ◽

Laure Peilleron ◽

Tatyana Grayfer ◽

Kevin Cariou

Keyword(s):

Natural Products ◽

Total Synthesis ◽

Asymmetric Reactions ◽

Recent Developments ◽

Halogenated Natural Products

This review covers the methods that chemists have developed to access halogenated polycyclic structures from polyenes, by emulating Nature’s enzymatic machineries. From pioneering studies to the most recent developments, the different strategies, whether based on the use of standard reagents or on the design of specific ones, will be presented. Finally, asymmetric reactions and applications for the total synthesis of natural products will be exposed.1 Introduction2 Pioneering Studies3 Use of Specific Reagents4 Use of N-Haloamides5 Asymmetric Reactions6 Total Synthesis of Halogenated Natural Products7 Conclusion and Perspectives

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Non-polar halogenated natural products bioaccumulated in marine samples. I. 2,3,3′,4,4′,5,5′-Heptachloro-1′-methyl-1,2′-bipyrrole (Q1)

Chemosphere ◽

10.1016/s0045-6535(03)00199-1 ◽

2003 ◽

Vol 52 (2) ◽

pp. 415-422 ◽

Cited By ~ 16

Author(s):

Walter Vetter ◽

Wu Jun ◽

Gerhard Althoff

Keyword(s):

Natural Products ◽

Marine Samples ◽

Halogenated Natural Products

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Identification and Quantification of “Quality Markers” in Tongkang Tablet on Recurrent Respiratory Tract Infections (RRTIs) by UFLC-IT-TOF–MS/MS and HPLC–DAD

Chromatographia ◽

10.1007/s10337-020-03881-4 ◽

2020 ◽

Vol 83 (5) ◽

pp. 631-646

Author(s):

Jinfang Ma ◽

Xue Zhou ◽

Chen Zhang ◽

Rongmin Yu ◽

Hong Pei ◽

...

Keyword(s):

Respiratory Tract ◽

Respiratory Tract Infections ◽

Quality Markers ◽

Tract Infections ◽

Recurrent Respiratory Tract Infections ◽

Tof Ms ◽

Identification And Quantification

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Capturing Nature's Oxonium Ions

10.26434/chemrxiv.7864337.v2 ◽

2019 ◽

Author(s):

Hau Sun (Sam) Chan ◽

Q. Nhu. N. Nguyen ◽

Jonathan Burton ◽

Robert Paton

Keyword(s):

Natural Products ◽

Direct Evidence ◽

Alkylating Agents ◽

Reactive Intermediates ◽

Total Syntheses ◽

Oxonium Ions ◽

Halogenated Natural Products

<a></a>Acetylcholine and S-adenosylmethionine exemplify the tetraalkylammonium (R4N+) and trialkylsulfonium (R3S+) ions used by Nature. The corresponding trialkyloxonium ions (R3O+), however, do not play a central role in biology most likely due to their hydrolytic instability compared with their ammonium and sulfonium counterparts. Indeed, Meerwein’s salts [(CH3)3O+BF4– and (CH3CH2)3O+BF4–], the simplest of the trialkyloxonium ions, are among the most powerful alkylating agents known, and they too are unstable to water. Only recently have water stable trialkyloxonium ions been reported which contain an oxatriquinane skeleton. Interestingly, despite the inherent hydrolytic instability of the vast majority of trialkyloxonium ions, they have been postulated as key intermediates in the biosynthesis of a number of complex natural products from Laurencia species. The existence of these complex trialkyloxonium ions has been implied from the structural and stereochemical diversity of these natural products and is supported by elegant biomimetic total syntheses, yet no direct evidence for their existence has been forthcoming. Herein, we report the synthesis and full characterisation of one family of these biosynthetically relevant trialkyloxonium ions - the most structurally and stereochemically complex oxonium ions characterised to date. Additionally, the elucidation of their in vitro reactivity profile has resulted in the synthesis of more than ten complex halogenated natural products. This work substantiates the existence of complex trialkyloxonium ions as key reactive intermediates in the biosynthesis of numerous halogenated natural products from L. spp. – expanding Nature’s rich inventory of onium ions.

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