(+)-Isoshinanolone and 2-methylbenzofuran-4-carbaldehyde from the fish-stunning plant Habropetalum dawei

Hanson, Svenja; Crawford, Malcolm; Thanasingh, Devavaram P.J.

doi:10.1016/0031-9422(81)83057-9

Cited by 17 publications

(12 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, conventional isolation procedures, which require significantly higher quantities, were not possible. Former classical investigations revealed the occurrence of the tetralone 4 , but no alkaloids have so far been reported. For a first overview, an HPLC−NMR on-flow experiment was performed (see Figure ).…”

Section: Resultsmentioning

confidence: 99%

HPLC−CD On-Line Coupling in Combination with HPLC−NMR and HPLC−MS/MS for the Determination of the Full Absolute Stereostructure of New Metabolites in Plant Extracts

et al. 1999

View full text Add to dashboard Cite

The applicability of on-line coupling of gradient eluted nonchiral reversed-phase high-pressure liquid chromatography (HPLC) to circular dichroism (CD) spectroscopy for the stereochemical analysis of crude plant extracts was investigated. A detector measuring simultaneously UV absorbances and CD effects at constant wavelengths in the same detection cell was used. The solvent system water/acetonitrile was found to be suited to give high-quality CD chromatograms as a function of the elution time and even complete characteristic CD spectra in the stop-flow mode. The method was applied to the tropical liana Habropetalum dawei (Dioncophyllaceae). First, the extract solution was investigated by the combined application of HPLC−NMR and HPLC−ESI-MS/MS techniques. The constitution and relative configuration of two as yet unknown natural products thus detected, the isoquinoline phylline (5) and the naphthylisoquinoline alkaloid 5‘-O-methyldioncopeltine A (6), were characterized. Subsequent HPLC−CD experiments permitted the deduction of the absolute configurations of these new metabolites by empirical analysis of their CD data. Thus, using identical sample solutions and chromatographic conditions (including the same columns and solvent gradient programs), the combination of NMR, MS, and CD data permitted the complete structural elucidation of the two new metabolites in the extract matrix solution, without any isolation and sample purification prior to the coupling experiments.

show abstract

Section: Resultsmentioning

confidence: 99%

HPLC−CD On-Line Coupling in Combination with HPLC−NMR and HPLC−MS/MS for the Determination of the Full Absolute Stereostructure of New Metabolites in Plant Extracts

et al. 1999

View full text Add to dashboard Cite

show abstract

“…Based on their spectroscopic features, compounds 2 – 5 were identified (Supporting Information) as trans -isoshinanolone ( 2 ), cis -isoshinanolone ( 3 ) [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], plumbagin ( 4 ) [ 26 , 27 , 28 , 29 , 30 ], and 3,3′-biplumbagin ( 5 ) [ 14 , 17 , 25 ]. Of the five isolated compounds 1 , 4 , and 5 possess rigid planar 1,4-naphthoquinone skeletons whereas the saturated hydroxyl-cyclohexanone ring of 2 and 3 allow some conformational flexibility.…”

Section: Resultsmentioning

confidence: 99%

Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis

et al. 2016

View full text Add to dashboard Cite

As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae), a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8′-oxo-biplumbagin (1) was isolated along with the known tetralones trans-isoshinanolone (2) and cis-isoshinanolone (3), and the naphthoquinones plumbagin (4) and 3,3′-biplumbagin (5). Compounds 2, 4, and 5 showed cytotoxicity (IC50 520–82.1 μM) against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC50 16.1, 29.7 and > 100 μg/mL, respectively), and for the methanol extract of the stem bark (IC50 59.6 μg/mL). The radical scavenging activity of the isolated constituents (1–5) was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

show abstract

“…Naphthalenones are a class of polyketidic natural products widely distributed in plants and fungal species. − Among these, three methyl-substituted naphthalenones such as cis -isoshinanolones ( 1 ), trans -isoshinanolone ( 2 ) and its biosynthetic precursor, plumbagin ( 3 ) were isolated first from a plant, Diospyros maritima by Tezuka (Figure A) . Since then, all of the stereoisomers of isoshinanolones including less abundant 2 , ent - 1 , and ent - 2 have been reportedly isolated from several plant species including Dioncophyllum thollonii, Habropetalum Dawei, Plumbago Scandens, Plumbago zeylanica, ,, and Ancistrocladus heyneanus, an Ancistrocladaceae species endemic to India , Despite their wide occurrence and bioactivity, the absolute configuration of isoshinanolones remained elusive due to the reports of conflicting optical rotation values for cis -isoshinanolone ( 1 ) isolated from different sources. ,, Only after Bringmann et al published a summary of the optical rotation values, the more abundant (+)-isoshinanolone ( 1 ) has been assigned (3 R ,4 R )-configuration .…”

mentioning

confidence: 99%

“…Since then, all of the stereoisomers of isoshinanolones including less abundant 2 , ent - 1 , and ent - 2 have been reportedly isolated from several plant species including Dioncophyllum thollonii, Habropetalum Dawei, Plumbago Scandens, Plumbago zeylanica, ,, and Ancistrocladus heyneanus, an Ancistrocladaceae species endemic to India , Despite their wide occurrence and bioactivity, the absolute configuration of isoshinanolones remained elusive due to the reports of conflicting optical rotation values for cis -isoshinanolone ( 1 ) isolated from different sources. ,, Only after Bringmann et al published a summary of the optical rotation values, the more abundant (+)-isoshinanolone ( 1 ) has been assigned (3 R ,4 R )-configuration . Likewise, the trans -isomer was assigned (3 R ,4 S )-configuration and is often referred to as epi -isoshinanolone ( 2 ) .…”

mentioning

confidence: 99%

“…1−3 Among these, three methyl-substituted naphthalenones such as cis-isoshinanolones (1), trans-isoshinanolone (2) and its biosynthetic precursor, plumbagin (3) were isolated first from a plant, Diospyros maritima by Tezuka (Figure 1A). 4 Since then, all of the stereoisomers of isoshinanolones including less abundant 2, ent-1, and ent-2 have been reportedly isolated from several plant species including Dioncophyllum thollonii, 5 Habropetalum Dawei, 6 Plumbago Scandens, 7 Plumbago zeylanica, 3,8,9 and Ancistrocladus heyneanus, an Ancistrocladaceae species endemic to India. 10 Cis-and trans-isoshinanolones (1 & 2) show antimicrobial and radical scavenging activities.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Highly Efficient One-Pot Multienzyme Cascades for the Stereoselective Synthesis of Natural Naphthalenones

Saha

Manna

et al. 2022

ACS Catal.

View full text Add to dashboard Cite

Herein, a biocatalytic cascade containing an ene-reductase (NostocER) and naphthol reductase (tetrahydroxynaphthalene or trihydroxynaphthalene reductase) of Magnaporthe grisea and NADPH is developed. The optimized multienzyme cascade is applied for the one-pot reduction of plumbagin to obtain biologically active cis-(3R,4R)-isoshinanolone, with dr cis:trans 98:2 and >99% ee in 96% yield. Furthermore, naturally occurring (+)-isosclerone, (+)-shinanolone, (−)-shinanolone, and (S)-4-hydroxy-3,4-dihydronaphthalen-1(2H)-one were also synthesized with excellent stereoselectivity and high yields (71–89%) using the enzymatic cascades. The investigation of NostocER–T4HNR-cascade reduction of menadione, plumbagin, and 5-methoxymenadione revealed specificity of tetrahydroxynaphthalene reductase toward these substrates. In addition, the kinetic studies showed a high catalytic efficiency of NostocER and T4HNR toward plumbagin and dihydroplumbagin, respectively, compared to other enzymes.

show abstract

(+)-Isoshinanolone and 2-methylbenzofuran-4-carbaldehyde from the fish-stunning plant Habropetalum dawei

Cited by 17 publications

References 3 publications

HPLC−CD On-Line Coupling in Combination with HPLC−NMR and HPLC−MS/MS for the Determination of the Full Absolute Stereostructure of New Metabolites in Plant Extracts

HPLC−CD On-Line Coupling in Combination with HPLC−NMR and HPLC−MS/MS for the Determination of the Full Absolute Stereostructure of New Metabolites in Plant Extracts

Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis

Highly Efficient One-Pot Multienzyme Cascades for the Stereoselective Synthesis of Natural Naphthalenones

Contact Info

Product

Resources

About