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.     

Methylated Chalcones from Bidens torta

Four new natural products, all methylated chalcones, including an acetylated glycoside, were isolated from Bidens torta. Their structures were determined by spectroscopic methods as okanin 3,4,3′,4′-tetramethyl ether, okanin 3,4,3′-trimethyl ether 4′-glucoside, okanin 4-methyl ether 4′-glucoside and okanin 4-methyl ether 4′-glucoside monoacetate. Okanin 3,4-dimethyl ether 4′-glucoside was also isolated.     

Flavone C-glycosides from Coronilla varia

One new and 5 known flavone C-glycosides were isolated from leaves and stems of Coronilla varia. The new compound was shown to be isoorientin 2″-O-rhamnoside. The known compounds were isovitexin, isoorientin, isovitexin 4′-O-glucoside, isoorientin 4′-O-glucoside, and isoorientin 7-O-glucoside.     

Cinnamate and shikimate incorporation into 3′,4′- and 3′,4′,5′-hydroxy substituted anthocyanins: Are there alternative pathways?

The incorporation of shikimate-[¹⁴C] and cinnamate-[¹⁴C] into 3′,4′- and 3′,4′,5′-hydroxy substituted anthocyanins was studied in isolated petals of Petunia hybrida. According to the dilution values, the incorporation of shikimate-[¹⁴C] was about 3–6 times better than that of cinnamate-[¹⁴C]. However a comparison of the incorporation of the 2 precursors on a relative basis showed no significant differences in the relative proportions of the specific activities of the 3′,4′-dihydroxysubstituted cyanidin-3-monoglucoside and the 3′,4′,5′-trihydroxysubstituted delphinidin-3-monoglucoside. This result and the [¹⁴C]-incorporation behaviour of the 3′-methoxy-4′-hydroxysubstituted peonidin-3-monoglucoside do not support the hypothesis that there are alternative pathways of flavonoid biosynthesis.     

Luteolin 7-glucuronide-3′-mono(trans)ferulylglucoside and other unusual flavonoids in the aquatic liverwort complex, Riccia fluitans

Thirteen flavonoid glycosides, including eight which are new have been identified in Riccia fluitans; aquatic and terrestrial forms of this plant have the same pattern. Luteolin 7-O-glucuronide-3′-O-mono(trans)ferulylglucoside is proposed as the type flavonoid for this species. Its absence from, and the presence of chrysoeriol in R. duplex, support the proposed separation of R. duplex from the R. fluitans complex. A micro-deacylation technique is described which can also be used for specific deglycosylation of luteolin glycosides at the 4′-hydroxyl.     

Flavans from Zephyranthes flava

A new optically active flavan aglucone, 7-hydroxy-3′,4′-methylenedioxyflavan, and its 7-glucoside have been isolated from the bulbs of Zephyranthes flava, collected at flowering. Additionally, two known flavans, 7,4′-dihydroxy-3′-methoxyflavan and 7-methoxy-2′-hydroxy-4′,5′-methylenedioxyflavan, have been isolated for the first time from this species. The structures of these flavans have been established by comprehensive analyses (UV, IR, ¹H NMR, ¹³C NMR, mass spectrometry, [α]_D) of the compounds and their acetates, and also by chemical correlation.     

Algal carotenoids with novel end groups

The structures of three previously unidentified carotenoids from Eutreptiella gymnastica are reported. These include siphonein with defined n-2-trans-2-dodecenoic esterifying acid and assigned 3R(?), 3′R,6′R chirality, (3R)-3′,4′-anhydrodiatoxanthin and eutreptiellanone (3,6-epoxy-3′,4′,7′,8′-tetradehydro-5,6-dihydro-β,β-caroten-4-one) with probable 3S,5R,6S chirality.     

Isoflavonoids from Myroxylon balsamum

Myroxylon balsamum (Leguminosae-Lotoideae) trunk wood contains a series of biogenetically related flavonoids, including the novel (±) -7-hydroxy-4′-methoxyisoflavanone, (±)-7,3′-dihydroxy-4′-methoxyisoflavanone and 2-(2′,4′-dihydroxyphenyl)-5,6-dimethoxybenzofuran.     

Synthesis of dihydrochalcones of Myrica gale

4,4,6-Trimethyl-2-(3-phenylpropionyl)cyclohexane-1,3,5-trione, 2′-hydroxy-4′,6′-dimethoxy-3′-methyldihydrochalcone, 2′,6′-dihydroxy-4′-methoxy-3′,5′-dimethyldihydrochalcone and 2,2,5-trimethyl-4(3-phenylpropionyl)cyclopent-4-ene-1,3-dione, constituents of Myrica gale, have been synthesized.     

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.     

Nucleosides and Nucleotides. 232. Synthesis of 2′-C-Methyl-4′-thiocytidine: Unexpected Anomerization of the 2′-Keto-4′-thionucleoside Precursor

The synthesis of 2′-C-methyl-4′-thiocytidine (16) is described. Since the 2′-keto-4′-thiocytidine derivative 2β unexpectedly isomerized to 2α and the methylation of 2β proceeded predominantly from the less hindered α-face to give 7, the desired product 16 was synthesized via the Pummerer reaction of the sulfoxide 14 and N ⁴ -benzoylcytosine.     

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.     

Flavones from Eupatorium leucolepis

Chloroform extraction of Eupatorium leucolepis gave the new flavones 3′-hydroxy-5,6,7,8,4′,5′-hexamethoxyflavone, 4′-hydroxy-5,6,7,8,3′,5     

Pyrenocine C,A phytotoxin-related metabolite produced by onion pink root fungus,Pyrenochaeta terrestris

The structure of pyrenocine C, a new metabolite isolated from onion pink root fungus, Pyrenochaeta terrestris (Hansen) has been elucidated as (±)-(2′E)-5-(1′-hydroxybut-2′-enyl)-4-methoxy-6-methyl-2-pyrone by spectroscopic methods and chemical correlation with pyrenocine A.     

Les constituants flavonoïdes de Cephalanthus spathelliferus

We have isolated from Cephalanthus spathelliferus (Rubiaceae) five compounds: umbelliferone, skimmin, 7,4′-dimethylkaempferol,7,4′-dimethylaromadendrin and its 5-glucoside. The latter two are new compounds.     

7,2′,4′-Trihydroxy-3′-methoxyisoflavone from zollernia paraensis

Three further compounds have been isolated from Zollernia paraensis: 2,7-dihydroxy-4′-methoxy-3-phenylcoumarin, (±)-5,7-dihydroxy-2′,4′-dimethoxyisoflavanone and the new 7,2′,4′-trihydroxy-3′-methoxyisoflavone.     

Dihydrochalcones from lindera umbellata

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

Thiolytic cleavage of the anti-tumour compound 4′-(9-acridinylamino)-methanesulphon-m-anisidine (m-AMSA,NSC 156 303) in blood

4′-(9-acridinylamino)methanesulphon-m-anisidide (m-AMSA), a compound with a broad spectrum of experimental anti-tumour activity, was found to have a short biological half-life in mice bearing L1210 leukaemia. The fate of m-AMSA [³H]-labelled in the acridine nucleus, was determined following injection into mice. There was rapid formation of covalent adducts with plasma proteins. Adducts were also formed in freshly isolated blood samples following incubation at 37°C, and were found to be highly fluorescent. The formation of adducts was accompanied by a decrease in the free thiol concentration in plasma, and the concomitant addition of radioactivity from [³H]acridine nuclei. Acid or alkaline hydrolysis of the plasma protein adduct liberated acridone, while digestion with a protease produced unstable fluorescent compounds. A comparison of the rates of acid hydrolysis of the adducts and of model compounds suggested that the adducts were produced as a result of nucleophilic attack at the C-9 position of m-AMSA by protein thiol groups. The side chain of m-AMSA was liberated as 4-amino-3-methoxymethanesulphonanilide. Several congeners of m-AMSA were shown to form similar or identical adducts both in vivo and in vitro, and at rates which correlated with their reactivity towards simple organic thiols.     

Anthocyanidin glycosides from the flowers of Alstroemeria

Three anthocyanins were isolated from the red flowers of four cultivars of Alstroemeria. Two compounds were novel anthocyanidin glycosides; the 3-rutinoside and 3-monoglucoside of 6-hydroxycyanidin. Cyanidin 3-rutinoside was also present in the petals.