Chalcone glycosides of Antirrhinum majus

Three chalcones have been found in yellow flowers of A. majus, two of which have been identified as chalcononaringenin 4′-glucoside and 3,4,2′,4′,6′-pentahydroxychalcone 4′-glucoside.     

Methoxyspheroidene and methoxyspheroidenone,two carotenoids from Rhodopseudomonas spheroides

Two new carotenoids isolated from Rhodopseudomonas spheroides (Rhodospirillaceae) have been identified as methoxyspheroidene (1,1′-dimethoxy-3,4-didehydro-1,2,1′,2′,7$\text{,}\text{?}$8′-hexahydro-ψ,ψ-carotene) obtained from anaerobic cultures and methoxyspheroidenone (1,1′-dimethoxy-3,4-didehydro-1,2,1′,2′,7′,8′-hexahydro-ψ,ψ-caroten-2-one) recovered from aerobic cultures.     

Two methylated flavones from Artemisia frigida

Two new highly oxygenated flavones were isolated from Artemisia frigida. Their structures were determined by spectroscopic methods as 5,7,4′-trihydroxy-6,3′,5′-trimethoxyflavone and 5,7,3′-trihydroxy-6,4′,5′-trimethoxyflavone.     

Myricetin and quercetin methyl ethers from Haplopappus integerrimus var. Punctatus

Nine flavonoids including two new myricetin derivatives, myricetin 3′,4′-dimethyl ether and myricetin 3,3′, 4′-trimethyl ether, were obtained from Haplopappus integerrimus var. punctatus. The known compounds are quercetin 7,3′-dimethyl ether, querectin 3,3′-dimethyl ether, isorhamnetin, quercetin 3,7-dimethyl ether, quercetin 3-methyl ether, quercetin and quercetin 3-β-d-glucoside.     

Flavonoids from Artemisia ludoviciana var. ludoviciana

Nineteen flavonoids were isolated from Artemisia ludoviciana var. ludoviciana, including a new 2′- hydroxy- 6-methoxyflavone, 5,7,2′,4′-tetrahydroxy-6,5′-dimethoxyflavone. The known compounds include quercetagetin 3,6,3′,4′-tetramethyl ether, eupatilin, 5,7-dihydroxy-3,6,8,4′-tetramethoxyflavone, luteolin 3′,4′-dimethyl ether, jaceosidin, 5,7,4′-trihydroxy-3,6-dimethoxyflavone, tricin, hispidulin, chrysoeriol, kaempferol 3-methyl ether, apigenin, axillarin, eupafolin, selagin and luteolin together with three flavones which were previously isolated for the first time from Artemisia frigida: 5,7,4′-trihydroxy-6, 3′,5′-trimethoxyflavone, 5,7,3′-trihydroxy-6,4′,5′-trimethoxyflavone and 5,7,3′,4′-tetrahydroxy-6,5′- dimethoxyflavone.     

Flavonoids from the exudate of Acacia neovernicosa

2′,4′-Dihydroxychalcone, 4′-hydroxy-2′-methoxychalcone and 2′,4′-dihydroxy-3′-methoxychalcone were isolated and characterized from the resinous exudate produced by Acacia neovernicosa. Smaller amounts of isoliquiritigenin, pinocembrin and chrysin were also found and identified by their chromatographic properties and UV spectra. The material of one collection contained galangin, 3-methylkaempferol and 3,3′ -dimethylquercetin.     

Two new C-methylated flavonoids from Myrica gale

From the leaves of Myrica gale 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone has been isolated. The fruits yielded 2′-hydroxy-4′,6′-dimethoxy-3′-methyldihydrochalcone. The constitutions were deduced from spectroscopic data and confirmed by synthesis.     

The structure and synthesis of neobavachalcone,a new component of Psoralea corylifolia.

Reinvestigation of the seeds of P. corylifolia has given, besides known compounds, a new formylated chalcone named neobavachalcone whose structure has been deduced as 5′-formyl-2′,4-dihydroxy-4′-methoxychalcone from spectral data and confirmed by synthesis. Its dimethyl ether has also been synthesised by an alternative procedure.     

Dihydrochalcones from lindera umbellata

Two dihydrochalcones, 2′,6′-dihydroxy-4′-methoxydihydrochalcone and 2,4′,6′-trihydroxydihydrochalcone have been isolated from leaves of Lindera umbellata.     

Isoflavones from Xanthocercis zambesiaca

In addition to the previously described 7-hydroxy-8,4′-dimethoxy- and 7,3′-dihydroxy-8,4′-dimethoxy-isoflavone the heartwood of Xanthocercis zambesiaca has been shown to contain 7-hydroxy-8,3′,4′-trimethoxy-,3′,4′-dimethoxy-6,7-methylenedioxy- and 8,3′,4′-trimethoxy-6,7-methylenedioxy-isoflavone. A technique of determining isoflavone hydroxylation patterns by deuterium labelling is described.     

7′,8′,11′,12′-Tetrahydro-γ-carotene: A novel carotene from Phycomyces blakesleeanus

The natural occurrence of 7′,8′,11′,12′-tetrahydro-γ-carotene (7′,8′,11′,12′-tetrahydro-γ-carotene, IV) is predicted and its isolation from diphenylamine-inhibited cultures of a mutant of Phycomyces blakesleeanus and characterization are described. The possible role of this novel monocyclic carotene in β-carotene biosynthesis is discussed.     

Germacranolides from Viguiera microphylla

Three new germacranolides, including two heliangolides (niveusin C-2′,3′-epoxide and 1,2-dehydroniveusin C-2′,3′-epoxide) and a germacrolide (3β-hydroxy-8β-epoxyangeloyloxycostunolide-1β,10α-epoxide) were isolated from Viguiera microphylla. Their structures were established by spectroscopic analyses, including extensive ¹H NMR and ¹³C NMR decoupling experiments and chemical transformations. X-ray diffraction analysis confirmed the structure of niveusin C-2′,3′-epoxide.     

Flavonoids of Gardenia cramerii and G. fosbergii bud exudates

From the bud exudates of Gardenia cramerii and G. fosbergii, two species endemic to Sri Lanka, a new flavonoid with an unusual B-ring oxidation pattern, 5,5′-dihydroxy-6,7,2′,3′-tetramethoxyflavone, was characterized. Two other rare flavonoids, 5,3′,5′-trihydroxy-3,6,7,4′-tetramethoxyflavone and 5-hydroxy-6,7,3′,4′,5′-pentamethoxyflavone were also isolated from both Gardenia species.     

Six 2′-hydroxyflavonols from Gutierrezia microcephala

Six 2′-hydroxyflavonols were isolated from Gutierrezia microcephala, including four new compounds, 5,7,2′-trihydroxy-3,6,4′,5′-tetramethoxyflavone, 5,7,2′-trihydroxy-3,6,8,4′,5′-pentamethoxyflavone, 5,2′-dihydroxy-3,6,7,8,4′,5′-hexamethoxyflavone and 5,7,2′,4′-tetrahydroxy-3,8,5′-trimethxoyflavone and two known compounds, 5,7,2′,5′-tetrahydroxy-3,6,8,4′-tetramethoxyflavone and 5,7,2′,4′-tetrahydroxy-3,6,8,5′-tetramethoxyflavone.     

Octasubstituted flavones from Ageratum houstonianum

Two new highly oxygenated flavones, were isolated from aerial parts of Ageratum houstonianum. Their structures were established as 3′-hydroxy-5,6,7,8,2′,4′,5′-heptamethoxyflavone and 5,3′-dihydroxy-6,7,8,2′,4′,5′-hexamethoxyflavone on the basis of spectral data and chemical degradation. The structure of the latter compound was confirmed by X-ray analysis.     

Flavonoids and isoflavonoids from Zollernia paraensis

The wood of Zollernia paraensis contains (+)-medicarpin, (+)-vestitol, isoliquiritigenin, formononetin, (±)-7-hydroxy-4′-methoxyisoflavanone, (±)-liquiritigenin and (+)-α-2′,4,4′-tetrahydroxydihydrochalcone.     

Polyphenols of Intsia heartwoods

Robinetin is the main polyphenol of the heartwood of Intsia bijuga and is accompanied by smaller amounts of 3,5,4′-tri- and 3,5,3′,4′-tetra-hydroxystilbenes, dihydromyricetin, myricetin and naringenin. The wood contains large amounts of water soluble polymers including leucocyanidin. The stilbenes are absent from the sapwood. Samples of I. bijuga and I. palembanica from several countries revealed differences in composition.     

4′-hydroxy-3,5,6,7,3′,5′-hexamethoxyflavone from Murraya paniculata

4′-Hydroxy-3,5,6,7,3′,5′-hexamethoxyflavone has been isolated from the leaves of Sri Lankan Murraya paniculata.     

Three highly oxygenated flavone glucuronides in leaves of Spinacia oleracea

Droplet counter-current chromatographic separation and subsequent TLC demonstrated the existence of at least 14 phenolics in the leaves of Spinacia oleracea. Three have now been isolated and identified, respectively, as the 4′-glucuronides of 5,7,4'-trihydroxy-3,6,3′-trimethoxyflavone (jaceidin), 5,3′,4′-trihydroxy-3-methoxy-6:7-methylene-dioxyflavone and 5,4′-dihydroxy-3,3′-dimethoxy-6:7-methylenedioxyflavone.