Prenylated flavonoids from Tephrosia apollinea

In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia,re-investigation of the methylenechloride/methanol(1:1) extract of the air-dried aerial part of Tephrosia apollinea afforded a new prenylated flavonoid 1, in addition to an aromatic ester,a sesquiterpene,a lignan and several known prenylated flavonoids.The structures were established by(~1H NMR,~(13)C NMR,DEPT,~1H-~1H COSY,HMQC,HMBC,NOESY and HRMS).Relative configurations of 9 and 10 were confirmed by X-ray anal...     

A new coumestan from Tephrosia calophylla

A new coumestan, tephcalostan (1) has been isolated from the whole plant of Tephrosia calophylla BEDD. together with two known flavonoids, 7-O-methylglabranin (2) and kaempferol 3-O-beta-D-glucopyranoside (3). The structure of tephcalostan was elucidated as 5'-(R)-8, 9-methylenedioxy-5'-isopropenyl-4', 5'-dihydrofurano[2', 3':2, 3]coumestan by extensive one-and two-dimensional (1D- and 2D-)-NMR techniques including (1)H-(1)H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments.     

A new prenylated flavanone from Derris trifoliata Lour

A new flavanone, 4',5,7-trihydroxy-6,8-di-(2-hydroxy-3-methylbut-3-enyl)- flavanone, was isolated from the aerial parts of Derris trifoliate, together with eleven known compounds: rotenone, tephrosin, 12a-hydroxyrotenone, deguelin, 6a,12a-dehydro-rotenone, dehydrodeguelin, 7a-O-methyldeguelol, 7a-O-methylelliptonol, 5,7,3',4'-tetra-hydroxy-6,8-diprenylisoflavone, daidzein and 4'-hydroxy-7-methoxyflavanone. 7a-O-Methylelliptonol was isolated for the first time from the genus Derris. Their structures were characterized on the basis of spectral data. Eight of the isolated compounds were found to be significantly toxic to brine shrimp (LC(50) range 0.06-9.95 μg/mL). The new compound showed weak toxicity (LC(50) = 211.31 μg/mL).     

A new flavanone glycoside isolated from Tournefortia sibirica

A new flavanone glycoside, (2S)-dihydrooroxylin A 7-O-[β-D-apiosyl(1→2)]-β-D-glucoside (1), and four known compounds (2–5) were isolated from Tournefortia sibirica L. The chemical structures of these compounds were determined by 1?D and 2?D NMR and HR-ESI-MS spectra, and results were compared with data from the literature. These five compounds (1–5) were isolated from the family Boraginaceae for the first time. Anti-inflammatory effects of compounds (1–5) were evaluated in terms of inhibition of production of NO, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells.     

Parkintin: a new flavanone with epoxy-isopentyl moiety from Parkinsonia aculeata Linn. (Caesalpiniaceae)

A new flavanone with epoxy-isopentyl moiety named parkintin has been isolated from the methanol soluble part of Parkinsonia aculeata Linn. belonging to the family Caesalpiniaceae. The structure of parkintin has been established with the aid of spectroscopic techniques including COSY and HMBC experiments.     

Two new flavanone glycosides from Macrothelypteris torresiana （Gaud.） Ching

Two new flavanone glycosides 1 and 2 were isolated from the aerial parts oi Macrothelypteris torresiana(Gaud.)Ching.The structures of two products were identified as(2S)-5,7,2',5'-tetrahydroxyfiavanone-2'-O-β-D-6"-O-acetylglucopyranoside and(2S)- 5,7,2',5'-tetrahydroxyflavanone-2'-O-β-D-glucopyranoside on the basis of their chemical and spectral analysis,respectively.     

Isolation of a new flavanone from Daidai fruit and hypolipidemic activity of total flavonoids extracts

In order to further discover the medicinal value of Daidai fruit, an exploration on the hypolipidemic activity of total flavonoids extracts of Daidai fruit (TFEODF) was conducted in high-fat diet-induced hyperlipemia rats. Results indicated that TFEODF exhibited significant hypolipidemic activity which resulted in the decline of serum total cholesterol, triglyceride, low density lipoprotein cholesterol, arteriosclerosis index and rise of high density lipoprotein cholesterol in hyperlipemia rats. For the purpose of expounding the chemical constituents of TFEODF, a phytochemical investigation of TFEODF was carried out for the first time. Research resulted in the isolation of a new compound together with 17 known compounds. This study lay a foundation for the development of a new hypolipidemic agent of traditional Chinese medicine whose chemical constituents were clarified.     

Isolation and structure elucidation of a flavanone, a flavanone glycoside and vomifoliol from Echiochilon fruticosum growing in Tunisia

A flavanone and a flavanone glycoside, together with vomifoliol, have been isolated for the first time from the aerial parts of the plant Echiochilon fruticosum and identified. Their structures were established on the basis of spectroscopic measurements, mainly 2D NMR using COSY, HMQC and HMBC experiments.     

A new flavanone glycoside from the dried immature fruits of Poncirus trifoliata

A new flavanone glycoside, (2R)-5-hydroxy-4'-methoxyflavanone-7-O-{beta-glucopyranosyl-(1-->2)-beta-glucopyranoside} (1), was isolated from the EtOAc extract of dried immature fruit of Poncirus trifoliata, together with three known compounds, (2S)-poncirin (2), (2S)-naringin (3), and (2S)-poncirenin (4). The structure of compound 1 was elucidated by spectroscopic data analysis, including 1D and 2D NMR experiments. Among the isolates, compound 2 exhibited considerable inhibitory activity against lipopolysaccharide (LPS)-induced prostaglandin E(2) (PGE(2)) and interleukin-6 (IL-6) production, and mRNA expression in RAW 264.7 murine macrophage cells.     

Antiplasmodial prenylated flavanonols from Tephrosia subtriflora

The CH₂Cl₂/MeOH (1:1) extract of the aerial parts of Tephrosia subtriflora afforded a new flavanonol, named subtriflavanonol (1), along with the known flavanone spinoflavanone B, and the known flavanonols MS-II (2) and mundulinol. The structures were elucidated by the use of NMR spectroscopy and mass spectrometry. The absolute configuration of the flavanonols was determined based on quantum chemical ECD calculations. In the antiplasmodial assay, compound 2 showed the highest activity against chloroquine-sensitive Plasmodium falciparum reference clones (D6 and 3D7), artemisinin-sensitive isolate (F32-TEM) as well as field isolate (KSM 009) with IC₅₀ values 1.4–4.6 μM without significant cytotoxicity against Vero and HEp2 cell lines (IC₅₀ > 100 μM). The new compound (1) showed weak antiplasmodial activity, IC₅₀ 12.5–24.2 μM, but also showed selective anticancer activity against HEp2 cell line (CC₅₀ 16.9 μM).     

Flavonoids from Tephrosia—VIII: The structure of elongatin,an isoflavone from Tephrosia elongata E. Mey.

The structure of elongatin, an isoflavone isolated from Tephrosia elongata E. Mey., has been established as 4′,5-dihydroxy-2′,5′-dimethoxy-2″,2″-dimethylpyrano[5″,6″-g]isoflavone.     

Two new acylated flavanone glycosides from the leaves and branches of Phyllanthus emblica

Two new acylated flavanone glycosides, (S)-eriodictyol 7-O-(6"-O-trans-p-coumaroyl)-beta-D-glucopyranoside (1) and (S)-eriodictyol 7-O-(6"-O-galloyl)-beta-D-glucopyranoside (2) were isolated from the leaves and branches of Phyllanthus emblica together with a new phenolic glycoside, 2-(2-methylbutyryl)phloroglucinol 1-O-(6"-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside (3), as well as 22 known compounds. Their structures were determined by spectral and chemical methods.     

Total assignments of 1H and 13C NMR spectra of a new prenylated flavanone from Dioclea grandiflora

A new prenylated flavanone, floranol ( 1 ) 3,5,7,2′‐ tetrahydroxy‐6‐methoxy‐8‐prenylflavanone and a known flavanone (dioclein) were isolated from the roots of Dioclea grandiflora (Fabaceae). The structure and the relative stereochemistry were established by 2D NMR spectroscopic techniques (HMQC and HMBC) Copyright © 2002 John Wiley & Sons, Ltd.     

Flavonoids from Tephrosia—VII : The constitution and absolute configuration of lupinifolin and lupinifolinol,two flavanones from Tephrosia lupinifolia Burch (DC)

The structure and absolute configuration of lupinifolin, (2S) - 4′,5 - dihydroxy - 8 - (3? - methyl - 2? - butenyl) - 2″, 2″ - dimethylpyrano[5″.6″ - g]flavanone, and lupinifolinol, (2R,3R) - 8 - (3? - methyl - 2? - butenyl) - 3,4′,5 - trihydroxy - 2″,2″ - dimethylpyrano[5″.6″ - g]flavanone, have been deduced from spectroscopic and chemical evidence.     

o-Bornylphenol: Stereochemistry and synthesis of new derivatives from its (+)-enantiomer

New derivatives of the (+)-enantiomer of o-bornylphenol were synthesized with a view to determine the configuration of chiral centers therein. The absolute configuration of the terpene substituents in the Mannich reaction product obtained from 4,13-diaza-18-crown-6 was estimated as (1R,2R,4S) on the basis of anomalous X-ray scattering.     

Flavonoids from Tephrosia—IX : The structure of multijugin and multijuginol

The structures of two flavones, multijuginol and multijugin, isolated from Tephrosia multijuga Young, have been established as 5-methoxy-2?,2?-dimethyl-3?-hydroxy-tetrahydrofurano[5?,4?-b]-dihydrofurano[5″,4″-h]flavone and the 3?-O-acetate derivative, respectively by means of spectral evidence and chemical degradation reactions.     

(+)-Lepidozene a new bicyclic sesquiterpene from the gorgonia lophogorgia ruberrima

(+)-Lepidozene 1, a new sesquiterpene possessing a trans-fused (8,1,0) undecane system, has been isolated from the gorgonia Lophogorgia ruberrima. Its structure and absolute configuration have been determined by spectroscopical methods and X-ray diffraction analysis.     

A new flavanone, reflexin, from Cuscuta reflexa and its selective sensing of nitric oxide

A new compound, reflexin, 5-hydroxy-7-methoxy-6-(2,3-epoxy-3-methylbutyl)-flavanone, is isolated from the stems of Cuscuta reflexa along with three other known compounds. This new compound has good potential for application especially in the photoactivity of reflexin. It was found to be sensitive to glutathione, forming a fluorescent product that is utilized for sensing nitric oxide (NO). The lowest detection limit of NO analysis was found to be 0.05 μM.