Coumarins from unripe fruits of Poncirus trifoliata

Petrol extracts of unripe fruits of Poncirus trifoliata L. were found to contain 7-geranyloxycoumarin, bergapten, imperatorin, 6-methoxy-7-geranyloxycoumarin and two new coumarins which were shown by chemical and spectroscopic means to be 7-(3′-methyl-2′,3′-epoxybutyloxy)-8-(3″-methyl-2″,3″-epoxybutyl)coumarin and 7-(3′-methyl-2′,3′-epoxybutyloxy)-8-(3″-methyl-2″-oxobutyl)coumarin respectively.     

New coumarins from Seseli sibiricum

Three new coumarins, sesebrin(7-methoxy-5-[3-methylbut-2-enyloxy]-8-[3-methyl-2,3-epoxybutyl] coumarin), sesebrinol(7-methoxy-5-[3-methylbut-2-enyloxy]-8-[3-methyl-2,3-dihydroxybutyl] coumarin) and sibiricol (7-methoxy-5-hydroxy-8-[3-methylbut-2-enyl] coumarin) have been isolated from the roots of Seseli sibiricum, in addition to sitosterol and 7 known coumarins, isobergapten, bergapten, phellopterin, sibiricin, coumurrayin, osthenol and meranzin hydrate.     

Coumarins of Skimmia japonica

The coumarins, isoimperatorin, isomeranzin, meranzin hydrate, oxypeucedanin, oxypeucedanin hydrate, oxypeucedanin methanolate and umbelliferone and the triterpene, friedoolean-14-en-3β-ol (taraxerol) were isolated from leaves of Skimmia japonica.     

Toddanol and toddanone,two coumarins from Toddalia asiatica

Two new constituents isolated from the roots of Toddalia asiatica and designated as toddanol and toddanone have been characterized as 5,7-dimethoxy-6-(2-hydroxy-3-methylbut-3-enyl)coumarin (1) and 5,7-dimethoxy-6-(3-methyl-2-oxobutanyl)coumarin (3), respectively, by spectral analysis and interconversion experiments.     

Simple coumarins from two populations of Diosma acmaeophylla

Investigation of two collections of Diosma acmaeophylla afforded seven simple coumarins, three of which were common to both samples. The chemotaxon     

New coumarins from the umbels of Seseli sibiricum

Three new coumarins, seselinal, sesibiricol and sibirinol, and 12 known coumarins have been isolated from the umbels of Seseli sibiricum. The new coumarins have been characterized as 5, 7-dimethoxy-8-(2-methyl-2-formylpropyl)-2H-1-benzopyran-2-one, 5-(3-methylbut-2-enyloxy)-7-methoxy-8-(2-hydroxy-3-methylbut-3-enyl)-2H-1-benzopyran-2-one and 5,7-dimethoxy-8-(2-hydroxy-3-methylbut-3-enyl)-2H-1-benzopyran-2-one,respectively. The known ones were identified as sesibiricin, isosibiricin, osthol, coumurrayin, sesebrin, sesebrinol, sibiricin, imperatorin, bergapten, xanthotoxin, isopimpinellin and mexoticin.     

Isolation and synthesis of two coumarins from melampodium divaricatum

Two new coumarin isomers have been isolated from Melampodium divaricatum and identified by spectral procedures as 8-hydroxy-7-(3′-methyl-2′-butenyloxy)coumarin (1) and 7-hydroxy-8-(3′-methyl-2′-butenyloxy)coumarin (2). The regioselective synthesis of each isomer was made by two different alkylation pathways confirming their structures.     

New antileishmanial sesquiterpene coumarins from Ferula narthex Boiss

Two new sesquiterpene coumarins, fnarthexone (1) and fnarthexol (2), along with three known coumarin derivatives, conferol (3), conferone (4) and umbelliferone (5), were isolated from the plant Ferula narthex Boiss. The structures of the compounds 1–5 were elucidated using modern spectroscopic techniques. The structure of compound 3 was unambiguously deduced by the single-crystal X-ray diffraction technique. Compounds 1–4 were tested for in vitro leishmanicidal activity and promising results were obtained. Conferol (3) was found to be the most potent with IC₅₀ value of 11.51 ± 0.09 μg/mL.     

Coumarins in Eremocitrus glauca; Rutaceae; chemotaxonomy; coumarins; artifact; MS fragmentation.

2′,3′-Dihydroxydihydrosuberosin its acetonide derivative and 7-hydroxycoumarin has been isolated from the extracts of Eremocitrus glauca. The s     

N-methylflindersine from Spathelia sorbifolia

The isolation and taxonomic significance of N-methylflindersine from S. sorbifolia is discussed.     

Coumarins from Amyris balsamifera

Two new coumarins have been isolated from the aerial parts of Amyris balsamifera. On the basis of spectral and chemical data, these have been identified as (R)-(+)-6-(2′-hydroxy-3′-methyl-3′-butenyl)-7-methoxycoumarin and balsamiferone, 7-hydroxy-3,6-bis (3′-methyl-2′-butenyl)-coumarin.     

7-Phenylacetoxy coumarin from limonia crenulata

A new coumarin, 7-phenylacetoxycoumarin, has been isolated from Limonia crenulata along with luvangetin, xanthotoxin, umbelliferone and limonin. This is the first report of a coumarin phenol ester from a natural source.