Differences in the floral anthocyanin content of violet–blue flowers of Vinca minor L. and V. major L. (Apocynaceae)

Two novel delphinidin 3-(tri or di)-glycoside-7-glycosides were isolated from the violet–blue flowers of Vinca minor L. and V. major L. (Family: Apocynaceae), and determined to be delphinidin 3-O-[2-O-(β-xylopyranosyl)-6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= delpphinidin 3-(2^G-xylosylrobinobioside)-7-rhamnoside] as major floral anthocyanin of V. minor and delphinidin 3-O-[6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= delpphinidin 3-robinobioside-7-rhamnoside] as major floral anthocyanin of V. major by chemical and spectroscopic methods. In addition, chlorogenic acid and kaempferol 3-O-[6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= kaempferol 3-robinobioside-7-rhamnoside (robinin)] were identified in these flowers. In this paper, the relation between the structure of floral anthocyanins and classification of Vinca species was discussed.     

Anthocyanin and pH in the color of ‘Heavenly Blue’ morning glory

The major anthocyanin in blue morning glory flowers, peonidin 3-(dicaffeylsophoroside)- 5-glucoside, is stable in a neutral aqueous solution and is solely responsible for the color of the flowers. Co-ocurring flavonols based on quercetin at the pH's of epidermal cells have no effect on the color of the anthocyanin. Deep or strong reddish-purple buds change to moderate or light blue open flowers within a 4 hr period, and during this time the pH of epidermal tissue increases from ca 6.5 to 7.5.     

Flavonoids in the blue flowers of Parochetus communis Buch.-Ham. ex D. Don (Leguminosae)

A rare anthocyanin, malvidin 3-O-rhamnoside, was isolated from the blue flowers of Parochetus communis Buch.-Ham. ex D. Don along with two known flavonols: kaempferol 3-O-(2-O-glucosyl-6-O-rhamnosyl)-glucoside and kaempferol 3-O-(2,6-di-O-rhamnosyl)-glucoside. These structures were identified using Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS).     

Flavonoid glycosides of Kalanchoe spathulata

A new glycoside, patuletin 3,7-di-O-rhamnoside, together with patuletin, quercetin, quercetin 3-O-glucoside-7-O-rhamnoside, kaempferol and kaempferol 3-O-rhamnoside were identified from leaves and flowers of Kalanchoe spathulata.     

Flavonol 3-glycosides from the leaves of Flemingia stricta

A new glycoside, tamarixetin 3-rhamnoside together with kaempferol 3-rhamnoside, mearnsetin 3-rhamnoside, quercetin 3-rhamnoside, myricetin 3-rhamnoside and sitosterol glucoside, was identified from the leaves of Flemingia stricta     

Flavonoids from Flindersia australis

Dihydrokaempferol, dihydrokaempferol 3-O-rhamnoside (engeletin) and kaempferol were isolated from the stem bark of Flindersia australis. This is the first report of the occurrence of these flavonoids in Flindersia.     

A malonylated anthocyanin and flavonols in blue Meconopsis flowers

The structures of the major anthocyanin and two flavonols from the blue flowers of Meconopsis were identified by NMR spectroscopy as being cyanidin 3-O-[(6-O-malonyl-2-O-B-D-xylopyranosyl)-beta-D-glucopyranoside]-7-O-beta-D-glucopyranoside, kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-glucopyranoside and kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside respectively.     

Relationship between the composition of flavonoids and flower colors variation in tropical water lily (Nymphaea) cultivars

Water lily, the member of the Nymphaeaceae family, is the symbol of Buddhism and Brahmanism in India. Despite its limited researches on flower color variations and formation mechanism, water lily has background of blue flowers and displays an exceptionally wide diversity of flower colors from purple, red, blue to yellow, in nature. In this study, 34 flavonoids were identified among 35 tropical cultivars by high-performance liquid chromatography (HPLC) with photodiode array detection (DAD) and electrospray ionization mass spectrometry (ESI-MS). Among them, four anthocyanins: delphinidin 3-O-rhamnosyl-5-O-galactoside (Dp3Rh5Ga), delphinidin 3-O-(2"-O-galloyl-6"-O-oxalyl-rhamnoside) (Dp3galloyl-oxalylRh), delphinidin 3-O-(6"-O-acetyl-β-glucopyranoside) (Dp3acetylG) and cyanidin 3- O-(2"-O-galloyl-galactopyranoside)-5-O-rhamnoside (Cy3galloylGa5Rh), one chalcone: chalcononaringenin 2'-O-galactoside (Chal2'Ga) and twelve flavonols: myricetin 7-O-rhamnosyl-(1 → 2)-rhamnoside (My7RhRh), quercetin 7-O-galactosyl-(1 → 2)-rhamnoside (Qu7GaRh), quercetin 7-O-galactoside (Qu7Ga), kaempferol 7-O-galactosyl-(1 → 2)-rhamnoside (Km7GaRh), myricetin 3-O-galactoside (My3Ga), kaempferol 7-O-galloylgalactosyl-(1 → 2)-rhamnoside (Km7galloylGaRh), myricetin 3-O-galloylrhamnoside (My3galloylRh), kaempferol 3-O-galactoside (Km3Ga), isorhamnetin 7-O-galactoside (Is7Ga), isorhamnetin 7-O-xyloside (Is7Xy), kaempferol 3-O-(3"-acetylrhamnoside) (Km3-3"acetylRh) and quercetin 3-O-acetylgalactoside (Qu3acetylGa) were identified in the petals of tropic water lily for the first time. Meanwhile a multivariate analysis was used to explore the relationship between pigments and flower color. By comparing, the cultivars which were detected delphinidin 3-galactoside (Dp3Ga) presented amaranth, and detected delphinidin 3'-galactoside (Dp3'Ga) presented blue. However, the derivatives of delphinidin and cyanidin were more complicated in red group. No anthocyanins were detected within white and yellow group. At the same time a possible flavonoid biosynthesis pathway of tropical water lily was presumed putatively. These studies will help to elucidate the evolution mechanism on the formation of flower colors and provide theoretical basis for outcross breeding and developing health care products from this plant.     

The blue anthocyanin pigments from the blue flowers of Heliophila coronopifolia L. (Brassicaceae)

Six acylated delphinidin glycosides (pigments 1-6) and one acylated kaempferol glycoside (pigment 9) were isolated from the blue flowers of cape stock (Heliophila coronopifolia) in Brassicaceae along with two known acylated cyanidin glycosides (pigments 7 and 8). Pigments 1-8, based on 3-sambubioside-5-glucosides of delphinidin and cyanidin, were acylated with hydroxycinnamic acids at 3-glycosyl residues of anthocyanidins. Using spectroscopic and chemical methods, the structures of pigments 1, 2, 5, and 6 were determined to be: delphinidin 3-O-[2-O-(β-xylopyranosyl)-6-O-(acyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside], in which acyl moieties were, respectively, cis-p-coumaric acid for pigment 1, trans-caffeic acid for pigment 2, trans-p-coumaric acid for pigment 5 (a main pigment) and trans-ferulic acid for pigment 6, respectively. Moreover, the structure of pigments 3 and 4 were elucidated, respectively, as a demalonyl pigment 5 and a demalonyl pigment 6. Two known anthocyanins (pigments 7 and 8) were identified to be cyanidin 3-(6-p-coumaroyl-sambubioside)-5-(6-malonyl-glucoside) for pigment 7 and cyanidin 3-(6-feruloyl-sambubioside)-5-(6-malonyl-glucoside) for pigment 8 as minor anthocyanin pigments. A flavonol pigment (pigment 9) was isolated from its flowers and determined to be kaempferol 3-O-[6-O-(trans-feruloyl)-β-glucopyranoside]-7-O-cellobioside-4′-O-glucopyranoside as the main flavonol pigment.On the visible absorption spectral curve of the fresh blue petals of this plant and its petal pressed juice in the pH 5.0 buffer solution, three characteristic absorption maxima were observed at 546, 583 and 635 nm. However, the absorption curve of pigment 5 (a main anthocyanin in its flower) exhibited only one maximum at 569 nm in the pH 5.0 buffer solution, and violet color. The color of pigment 5 was observed to be very unstable in the pH 5.0 solution and soon decayed. In the pH 5.0 solution, the violet color of pigment 5 was restored as pure blue color by addition of pigment 9 (a main flavonol in this flower) like its fresh flower, and its blue solution exhibited the same three maxima at 546, 583 and 635 nm. On the other hand, the violet color of pigment 5 in the pH 5.0 buffer solution was not restored as pure blue color by addition of deacyl pigment 9 or rutin (a typical flower copigment). It is particularly interesting that, a blue anthocyanin-flavonol complex was extracted from the blue flowers of this plant with H₂O or 5% HOAc solution as a dark blue powder. This complex exhibited the same absorption maxima at 546, 583 and 635 nm in the pH 5.0 buffer solution. Analysis of FAB mass measurement established that this blue anthocyanin-flavonol complex was composed of one molecule each of pigment 5 and pigment 9, exhibiting a molecular ion [M+1] ⁺ at 2102 m/z (C₉₃H₁₀₅O₅₅ calc. 2101.542). However, this blue complex is extremely unstable in acid solution. It really dissociates into pigment 5 and pigment 9.     

Continuous ethanol production by yeast immobilized on to channeled alumina beads

Vertical and near-horizontal (15° angle) packed-bed columns were compared for continuous ethanol fermentation using an alcohol- and glucose-tolerant Saccharomyces cerevisiae strain immobilized on to channeled alumina beads (5·0 × 10⁹ cells g⁻¹ beads). Spaces between beads (1·0–6·5 mm) and angle (15°) of near-horizontal reactor columns (with six ports in each) efficiently removed CO₂ and increased ethanol productivity. Malt-glucose-yeast-extract broth containing 16·7% glucose at 35°C fed at a dilution rate of 3· h⁻¹ to thw two horizontal columns (in series) yielded maximum ethanol productivity of 40·0 g liter⁻¹ h⁻¹. Feedstock flow rate and other factors (temperature, pH, nutrients, and glucose levels) affected productivities. The immobilized-cell system showed operational stability for >3 months without plugging, and could be stored for at least one year with no loss of bioreactor performance. Scanning electron micrographs of the beads revealed large numbers of yeast-cells attached on to internal and external surfaces of beads.     

Covalent anthocyanin-flavonol complexes from flowers of chive, Allium schoenoprasum

The structures of eight anthocyanins have been determined in acidified methanolic extract of pale-purple flowers of chive, Allium schoenoprasum. Four of them have been identified as the anthocyanin-flavonol complexes (cyanidin 3-O-beta-glucosideAII) (kaempferol 3-O-(2-O-beta-glucosylFIII-beta-glucosideFII)-7-O-beta-gl ucosiduronic acidFIV) malonateAIII (AII-6-->AIII-1, FIV-2-->AIII-3), 1, (cyanidin 3-O-(3-O-acetyl-beta-glucosideAII) (kaempferol 3-O-(2-O-beta-glucosylFIII-beta-glucosideFII)-7-O-beta-gl ucosiduronic acidFIV) malonateAIII (AII-6-->AIII-1, FIV-2-->AIII-3), 2, and their 7-O-(methyl-O-beta-glucosiduronateFIV) analogous, 3 and 4. Pigments 1 and 2 are the first final identification of covalent complexes between an anthocyanin and a flavonol, while 3 and 4 are formed during the isolation process. The other four anthocyanins (5-8) were found to be the 3-acetylglucoside, 3-glucoside, 3-(6-malonylglucoside) and 3-(3,6-dimalonylglucoside) of cyanidin. The three latter pigments have earlier been identified as the major anthocyanins of the chive stem. The covalent anthocyanin-flavonol complexes show intramolecular association between the anthocyanidin (cyanidin) and flavonol (kaempferol) units, which influence the colour.     

Flavonoid constituents of Ephedra alata

Two new flavonol glucosides have been identified in Ephedra alata, namely, herbacetin 8-methyl ether 3-O- glucoside-7-O-rutinoside and herbacetin 7-O-(6″-quinylglucoside). The known flavonoids vicenin II, lucenin III, kaempferol 3-rhamnoside, quercetin 3-rhamnoside and herbacetin 7-glucoside were also found. The structure of the isolated compounds was determined mostly by FABMS and ¹H NMR spectroscopy. The final structure of the new compounds and of herbacetin 7-glucoside was confirmed by ¹³C NMR spectroscopy.     

The effects of copper, iron and zinc on digestive enzyme activity in the hybrid tilapia Oreochromis niloticus (L.) ×Oreochromis aureus (Steindachner)

The present experiment was conducted to study effects of Cu, Fe and Zn on activities of digestive enzymes of the hybrid tilapia Oreochromis niloticus×Oreochromis aureus. The acidic protease activities increased 65·5 and 55·1% by addition of homogenates of digesta‐containing stomach with copper (75 mg l⁻¹) and zinc (50 mg l⁻¹) respectively. Addition of Cu and Zn increased the activities of protease in the hepatopancreas homogenates by 132·7 and 38·1% respectively, and reduced the activity of protease in the digesta‐containing intestine homogenates by 11·0 and 13·8% respectively. Addition of Fe (50 mg l⁻¹) increased the acidic protease activity by 96·7% but did not alter the activities of protease in the intestine and hepatopancreas. Addition of Cu markedly inhibited activities of amylase in intestine and hepatopancreas homogenates, while Zn addition showed no effects. Addition of Fe reduced activities of amylase in the intestine homogenates by 47·9% but had no effect on amylase activities in the hepatopancreas. When Cu (75 mg kg⁻¹), Fe (50 mg kg⁻¹) and Zn (50 mg kg⁻¹) were supplemented to basal diet for 3 weeks, the activities of amylase in hepatopancreas homogenates increased 125·3, 215·6 and 70·0%, respectively, the activities of amylase in intestine increased 79·8, 74·6 and 48·5%, respectively, and the activities of lipase in intestine increased 90·5, 149·8 and 84·0%, respectively. Supplementation of Cu, Fe or Zn into diet had no effects on activity of protease in all digestive organs. Therefore, the results suggest that effects of Cu, Fe and Zn on activity of digestive enzymes in vitro were different from those seen in vivo, and that the positive effects of Cu, Fe and Zn supplemented to fish diet would be valuable information for formulating fish feed.     

Spectral characteristics of human fetal adrenal microsomes.

Investigations of human fetal adrenal gland microsomes indicated that a carbon monoxide binding pigment had an absorption maximum of 446 to 448 nm. This pigment, upon heat treatment at 37°C was degraded to the form of cytochrome p-420. NADPH reduced cytochrome p-450 slowly and completely. Typical concentrations of 0.75 and 0.16 nmoles/mg protein cytochrome P-450 and b₅, respectively, were observed. Reduced ethylisocyanide spectra were similar to those of rat hepatic microsomes with absorption maxima at 430 as well as 454 nm. Typical type I spectral changes were observed with progesterone, 17-α-OH-progesterone, pregnenolone and androstenedione when these steroids were added to the sample cuvettes. Androstenedione exhibited an apparent spectral dissociation constant (K_S) of 5×10⁻⁶M pregnenolone and progesterone exhibited higher affinities with apparent dissociation constants of 1.1×10⁻⁷M and 1.8×10⁻⁷M, respectively. The maximal absorbance change induced by androstenedione was lower (Emax = 0.027 per mg protien) than the changes in absorbance maxima induced by pregnenolone or progesterone (Emax = 0.060 and 0.047 per mg protein, respectively) when saturating concentrations of these steroids were added to the sample cuvettes. Ethylmorphine and aminopyrine (10⁻³M final concentrations) did not exhibit observable spectral changes; however, type II spectra could be elicited with aniline and nicotinamide and apparent dissociation constants of 3.5×10⁻²M and 2.5×10⁻²M, respectively, were obtained.     

Trisubstituted flavonol glycosides in Coronilla emerus flowers

A novel trisubstituted kaempferol glycoside has been isolated from leaves and flowers of Coronilla emerus and identified as the 3-glucoside-7,4′-dirhamnoside. It co-occurs in the flowers with the 3-glucosides and 3-glucoside-7-rhamnosides of kaempferol and quercetin. A second kaempferol triglycoside based on glucose and xylose is also present. All six glycosides contribute to the UV patterning present in the wings of the flowers. This is the first report of kaempferol triglycosides with monosaccharide units substituting hydroxyl groups at the 3-, 7- and 4′-positions.     

Cultivation of Lemna gibba under desert conditions. I: Twelve months of continuous cultivation in open ponds

Duckweed, Lemna gibba, was grown in 12 m² shallow ponds in the Negev desert, during 12 months of continuous cultivation, beginning April 1984. Average monthly growth rates varied with the season of the year. The lowest daily yield, 2·6±0·4 g dry weight m⁻² day⁻¹, was obtained during January. Highest daily yields, 7·9±2·6 g dry weight m⁻² day⁻¹ and 7·0±1·2 g dry weight m⁻² day⁻¹, were obtained during September and May. A 35% decline of the yield was seen during midsummer (July), 4·8±1·2 g dry weight m⁻² day⁻¹. The average rate for the year was 5·15±1·7 g dry weight m⁻² day⁻¹. The protein content of the plants ranged from 30 to 38% per unit dry weight.Growth performance is discussed in relation to the prevailing climatic conditions.     

Algal biomass production,N uptake and N2 fixation in a synthetic medium

An experiment was conducted in the growth chamber to quantify the biomass production, N removal and N₂ fixation from a synthetic medium by Chlamydomonas reinhardtii and Anabaena flos-aquae. Nitrogen was supplied at a concentration of 100 mg liter⁻¹ of NO₃⁻−¹⁵N and NH₄⁺−¹⁵ (3·5 atom %), respectively. After 21 days Chlamydomonas reinhardtii removed an average of 83·8 and 78·7 mg N liter⁻¹ as NO₃⁻ and NH₄⁺, respectively. Averages of 0·89 and 0·71 g liter⁻¹ (first batch), 1·63 and 0·95 g liter⁻ (second batch) algal biomass were collected from NO₃⁻ and NH₄⁺ media, respectively. Uptake rates of 0·11 mg ¹⁵N g⁻¹ algae day⁻¹ from NO₃⁻ medium and 0·10 mg ¹⁵N g⁻¹ algae day⁻¹ from NH₄⁺ medium were calculated. Algal cells grown in NO₃⁻ and NH₄⁺ medium contained 71 and 65 g N kg⁻¹ (first batch), 39 and 58 g N kg⁻¹ (second batch), respectively. Anabaena flos-aquae produced averages of 0·58 and 0·46 g liter⁻¹ (first batch), 0·55 and 0·48 g liter⁻¹ (second batch) after 14 days of growth from NO₃⁻ and NH₄⁺ media, respectively. Blue-green algal biomass contained higher N (81–98 g kg⁻¹) than green algae. Isotope dilution method for determining N₂ fixation indicated that 55% and 77% of total N of blue-green algae grown in NO₃⁻ and NH₄⁺ media, respectively, was derived from the atmosphere.     

Flavonol glycosides of Warburgia ugandensis leaves

Four new flavonol gycosides: kaempferide 3-O-beta-xylosyl (1-->2)-beta-glucoside, kaempferol 3-O-alpha-rhamnoside-7,4'-di-O-beta-galactoside, kaempferol 3,7,4'-tri-O-beta-glucoside and quercetin 3-O-[alpha-rhamnosyl (1-->6)] [beta-glucosyl (1-->2)]-beta-glucoside-7-O-alpha-rhamnoside, were characterized from a methanolic leaf extract of Warburgia ugandensis. The known flavonols: kaempferol, kaempferol 3-rhamnoside, kaempferol 3-rutinoside, myricetin, quercetin 3-rhamnoside, kaempferol 3-arabinoside, quercetin 3-glucoside, quercetin, kaempferol 3-rhamnoside-4'-galactoside, myricetin 3-galactoside and kaempferol 3-glucoside were also isolated. Structures were established by spectroscopic and chemical methods and by comparison with authentic samples.     

Ca2+-mobilizing receptors of gastrulating chick embryo

1. Gastrulating chick embryo cells (stages 3–5 by HH) possess Ca²⁺-mobilizing receptors for ACh and ATP; insulin and noradrenaline have a weaker effect on [Ca²⁺], mobilization.2. The ed₅₀ value for ACh is 4 (±0.5)· 10⁻⁶M and for ATP 20 (±5)· 10⁻⁶M.3. Addition of ACh and ATP to dissociated chick embryo cells causes rapid accumulation of IP₃.4. The stimulatory effects of ACh and ATP on [Ca²⁺], mobilization and IP₃ rapid formation are both additive.     

Flavonoid glycosides from fiveCyathea species

The leaves of 5 fern species of the genusCyathea, i.e.C. fauriei, C. mertensiana, C. leichhardtiana, C. podophylla andC. hancockii, have been chemically analysed. The former 3 species have kaempferol 3-sophoroside (sophoraflavonoloside) and kaempferol 7-rhamnoglucoside as glycosidic components, and the latter 2 species contain kaempferol 3-galactoside (trifolin) and kaempferol 3-rhamnoglucoside (nicotiflorin). In addition, vitexin, orientin, kaempferol 3-glucoside (astragalin), kaempferol 3-rhamnoside (afzelin) and kaempferol 7-arabinoside are detected as common constituents in all the 5 species analysed.