Squarrosine A and Pyrrolhuperzine A, New Lycopodium Alkaloids from Thai and Philippine Huperzia squarrosa

Nilsu, Thanasan; Thorroad, Sakornrat; Ruchirawat, Somsak; Thasana, Nopporn

doi:10.1055/s-0042-106904

Cited by 23 publications

(27 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As no differences were observed in retention time and in fragmentation pattern (Figure ), it could be concluded that the samples actually contained the esters of homopipecolic acid and homoproline. Homopipecolic acid was described before in Lycopodium species as an intermediate of the synthesis of Lycopodium alkaloids, while homoproline was isolated from Asteraceae species, as a precursor of pyrrolizidines, but their co‐occurrence has never been reported in plants and their biosynthetic origin is not known.…”

Section: Resultsmentioning

confidence: 99%

“…Homopipecolic acid was described before in Lycopodium species as an intermediate of the synthesis of Lycopodium alkaloids, 41,42 while homoproline was isolated from Asteraceae species, as a precursor of pyrrolizidines, 40 but their co-occurrence has never been reported in plants and their biosynthetic origin is not known.…”

Section: Identification Of Beta Amino Acid Derivativesmentioning

confidence: 99%

See 1 more Smart Citation

Phytochemical analysis of Ononis arvensis L. by liquid chromatography coupled with mass spectrometry

et al. 2019

View full text Add to dashboard Cite

Ononis arvensis L. can be found overall in Europe and is used to treat infections of the urinary tract and skin diseases in ethnopharmacology. Flavonoids, hydroxycinnamic acids, oxycoumarin, scopoletin and scopolin, phytosterols, lectins, and some selected isoflavonoids were identified in O. arvensis till date; however, there is a lack of the detailed investigation of the isoflavonoid profile of the plant. With the application of high‐resolution tandem mass spectrometry, the fragmentation patterns of isoflavonoid derivatives found in O. arvensis roots and aerial parts were investigated and discussed. Isoflavonoid glucosides, glucoside malonates, aglycones, and beta amino acid derivatives were characterized, among which homoproline isoflavonoid glucoside esters were described for the first time. Besides the known isoflavonoid aglycones described earlier in other Ononis species, two 2′‐methoxy isoflavonoid derivatives were detected. The presence of licoagroside B was verified, and its structure was also corroborated by NMR experiments. Altogether, the high‐resolution fragmentation pattern of 47 isoflavonoids and glycosides is presented, and their relative quantity in the roots and the aerial parts can be evaluated. Based on this information, the chemotaxonomic relation of Ononis species and the biosynthesis of their compounds could be comprehended to a greater depth.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Identification Of Beta Amino Acid Derivativesmentioning

confidence: 99%

Phytochemical analysis of Ononis arvensis L. by liquid chromatography coupled with mass spectrometry

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Such an asymmetric transformation could efficiently address the intrinsic challenges of the classic intramolecular Schmidt reaction, [10] including the use of azides with low nucleophilicity as a substrate, the general requirement for stoichiometric amounts of a strong Lewis or Brønsted acid to activate the carbonyl group of the other reactant, the relatively strong Lewis basic nature of the resulting lactam, and the lack of the corresponding catalytic asymmetric fashion. Notably, the resulting chiral bicyclic lactams could be used as the key precursors for the total synthesis of various bioactive alkaloids, such as cephalotaxine, [4b] squarrosine A, [4c] and fluvirosaone B [4d] . Herein, we report a novel copper‐nitrene‐catalyzed asymmetric intramolecular tandem oxaziridination/rearrangement reaction to produce a chiral fused bicyclic lactam.…”

Section: Methodsmentioning

confidence: 99%

Copper‐Nitrene‐Catalyzed Desymmetric Oxaziridination/1,2‐Alkyl Rearrangement of 1,3‐Diketones toward Bicyclic Lactams

et al. 2021

View full text Add to dashboard Cite

Although copper-nitrene has been extensively studied as a versatile active species in various transformations, asymmetric reactions involving copper-nitrene have been limited to the aziridination of olefins. Herein, we report the novel copper-nitrene-catalyzed desymmetric oxaziridination reaction of cyclic diketones with alkyl azides and the subsequent rearrangement of the resulting highly active intermediate, which produces a synthetically challenging chiral bicyclic lactam containing a quaternary carbon center. This procedure not only enriches the copper-nitrene-catalyzed asymmetric reactions, but also provides an alternative strategy to address the inherent challenges of catalytic asymmetric Schmidt reactions. This unique reaction could inspire the investigation of novel copper-nitrene-catalyzed asymmetric transformations and their reaction mechanisms.Scheme 1. The outline of Cu-catalyzed asymmetric reactions involving nitrenoid intermediates.

show abstract

“…Löve & D. Löve (Huperziaceae) is an epiphytic clubmoss mainly distributed in Southeast Asia, Oceania, and Southwest China that can be found on trees and rocks in lowland to mid-altitude forests . The first study on the alkaloidal constituents of this plant was reported in 2011; since then, dozens of Lycopodium alkaloids with diverse structures have been isolated. − As part of our ongoing search for structurally intriguing and biologically significant alkaloids, , the aerial parts of P. squarrosus collected from Guangxi Zhuang Autonomous Region of China were studied. This investigation led to the isolation of 18 new Lycopodium alkaloids, namely, eight lycopodine-type ( 1 – 8 ), seven lycodine-type ( 9 – 15 ), two fawcettimine-type ( 16 and 17 ), and a miscellaneous alkaloid ( 18 ), as well as eight known alkaloids.…”

mentioning

confidence: 99%

Lycosquarrines A–R, Lycopodium Alkaloids from Phlegmariurus squarrosus

et al. 2020

View full text Add to dashboard Cite

Eighteen new Lycopodium alkaloids, lycosquarrines A−R (1−18), and eight known alkaloids were isolated from the aerial parts of Phlegmariurus squarrosus. Compounds 1−5 and 19, identified from natural sources for the first time, are uncommon lycopodine-type alkaloids with β-oriented H-4. Pentacyclic 4 and 5 represent the first examples of 5,12-and 5,11-epoxy Lycopodium alkaloids, respectively, and an epoxide-opening cyclization reaction is suggested to be a key step in their biosynthesis. Compound 18 possesses the same carbon skeleton as carinatine A ( 22), which was previously reported as a unique Lycopodium alkaloid with a 5/ 6/6/6 ring system. X-ray crystallographic data analysis was used to determine the absolute configuration of 18, leading to the establishment of the absolute configuration of 22 by comparison of the ECD spectra. An anti-acetylcholinesterase activity assay showed that 11 and 20 exhibited inhibitory activities with IC 50 values of 4.2 and 2.1 μM, respectively.

show abstract

Squarrosine A and Pyrrolhuperzine A, New Lycopodium Alkaloids from Thai and Philippine Huperzia squarrosa

Cited by 23 publications

References 21 publications

Phytochemical analysis of Ononis arvensis L. by liquid chromatography coupled with mass spectrometry

Phytochemical analysis of Ononis arvensis L. by liquid chromatography coupled with mass spectrometry

Copper‐Nitrene‐Catalyzed Desymmetric Oxaziridination/1,2‐Alkyl Rearrangement of 1,3‐Diketones toward Bicyclic Lactams

Lycosquarrines A–R, Lycopodium Alkaloids from Phlegmariurus squarrosus

Contact Info

Product

Resources

About