Isoflavones of Iris spuria

A new isoflavone, 5,7-dihydroxy-6,2′-dimethoxyisoflavone, together with iristectorigenin A and iristectorin A were isolated and characterized from the methanol extract of Iris spuria.     

Two new flavonoid glycosides from Iris tectorum

Phytochemical investigation of the ethanol extract of rhizomes of Iris tectorum resulted in the isolation and characterization of two new flavonoid glycosides, tectorigenin-7-O-β-d-fucopyranoside (1), 3,5,4′-trihydroxy-7,3′-dimethoxyflavanone-5-O-α-l-rhamnopyranoside (2), together with two known ones (3, 4). The rhamnose substituent at C-5 displayed uncommon connection in naturally occurring flavonoid glycosides. Their structures were elucidated on the basis of extensive spectroscopic analysis. All of the isolates were evaluated for their in vitro inhibitory activity against aldose reductase.     

Phenolic constituents of Iris milesii rhizomes

Analysis of a methanol extract of the rhizomes of Iris milesii resulted in the isolation of a new isoflavone, 5,6,7,4′-tetrahydroxy-8-methoxyisoflavone along with prunetin, sakuranetin, 2:6-dimethoxy-1,4-benzoquinone, tectorigenin, irigenin,4-β(D-glucosyloxy)-ferulic acid methyl ester, quercetin-3-methyl ether, tectoridin, iridin and iristectorin B.     

德国鸢尾对Cd胁迫的生理生态响应及积累特性

通过盆栽研究了Cd胁迫下德国鸢尾的生长状况、生态效应、生理特性及吸收和富集Cd的能力.结果表明:德国鸢尾对小于5 mg/kg的Cd有较强的耐性,适用于城区土壤修复;Cd浓度大于5 mg/kg时抑制德国鸢尾生长,降低了其生态效应.随着Cd浓度的增大,德国鸢尾根系活力、叶绿素含量和含水量逐渐降低,游离脯氨酸和可溶性糖含量先升高后降低,细胞膜透性逐渐升高.Cd在德国鸢尾体内分布为根系＞地上部分,随着Cd浓度的增大,德国鸢尾根系和地上部分Cd积累浓度逐渐升高、富集系数和转运系数逐渐降低;Cd浓度为20 mg/kg时德国鸢尾对Cd的积累量最大,为2.122 mg/plant.     

云南鸢尾属一新种

报道了鸢尾属植物一新种,即哈巴鸢尾(Iris habanesis X. D. Dong)。该种以植株矮小,花茎单一不分枝,具鸡冠状附属物与尼泊尔鸢尾不同,同时又以花期花茎长15~20 cm而与高原鸢尾有所不同。     

Relationship between subfamilies,tribes and genera in iridaceae inferred from chemical characters

Free amino acids and γ-glutamyl peptides have been examined in 22 species of Iridaceae. 3-(3′-Carboxyphenyl)alanine and 3′-carboxyphenylglycine, previously known from the tribes Irideae and Tigridideae in the subfamily Iridodeae have been identified also in the tribe Mariceae of Iridoideae and the genera Bobartia, Orthrosanthus and Libertia of the subfamily Sisyrinchioideae. γ-Glutamyl peptides, previously known from the tribe Irideae, have been found also in the tribe Mariceae, both tribes being from subfamily Iridoideae. γ-Glutamyl-S-methylcysteine, γ-glutamylmethionine and the corresponding sulphoxides are the dominating γ-glutamyl peptides in the genera Dietes, Gynandriris, Moraea (tribe Irideae), Neomarica and Trimezia (tribe Mariceae), whereas γ-glutamyl peptides with non-sulphur amino acids are predominant in genera Ferraria, Hermodactylus, Homeria, Iris, Iridodyctyum and Xiphium (tribe Irideae). Dietes robisoniana, endemic to Lord Howe Island, has the same technical characters as other Dietes species from Southern Africa. The results are discussed in relation to botanical classification of and within the subfamilies Iridoideae and Sisyrinchoideae.     

On the Chemical Structure of a New Isoflavone Glucoside,Homotectoridin, Isolated Together with Tectoridin from the Rhizomes of Iris germanica Linnaeus

Homotectoridin (II), C₂₃H₂₄O₁₂ H₂O, mp 186°C, a new isoflavone isolated from ethanolic extracts of the rhizomes of Iris germanica Linnaeus, was formulated as 5,4′-dihydroxy-8,3′dimethoxy-isoflavone-7-O-mono-d-glucoside. Tectoridin (I) was also isolated from the same extract.     

Karyological studies of some species of the Mongolian flora

The paper gives the chromosome numbers for 38 species of the Mongolian Flora. Some of the counts appear to be the first findings for the species. They are:Allium anisopodium 2n = 16, Caltha membranacea 2n = 32, Carex macroura 2n = 50, Carex redowskiana 2n = 26, Gastrolychnis brachypetala 2n = 72, Iris biglumis 2n = 40, Iris flavissima 2n = 28 andVicia multicaulis 2n = 24.     

8-Hydroxyirilone 5-methyl ether and 8-hydroxyirilone,new antioxidant and α-amylase inhibitors isoflavonoids from Iris germanica rhizomes

Iris species are well recognized as wealthy sources of isoflavonoids. In the present study, phytochemical investigation of the rhizomes of Iris germanica (Iridaceae) procure the isolation of two new isoflavonoids namely, 8-hydroxyirilone 5-methyl ether (2) and 8-hydroxyirilone (3), along with eight known isoflavonoids: irilone 4′-methyl ether (1), irilone (4), irisolidone (5), irigenin S (6), irigenin (7), irilone 4′-O-β-d-glucopyranoside (8), iridin S (9), and iridin (10). The isolated flavonoids were structurally characterized with the assist of comprehensive spectroscopic analyses (UV, IR, 1D and 2D NMR, and HRMS) and comparing with the published data. They were estimated for their antioxidant and antidaibetic capacities using DPPH and α-amylase inhibition assays, respectively. Compounds 2, 3, and 4 exhibited prominent antioxidant activities with IC₅₀ values of 12.92, 9.23, and 10.46 μM, respectively compared to propyl gallate (IC₅₀ 7.11 μM). Moreover, 2–5 possessed highest α-amylase inhibitory activity with % inhibition 66.1, 78.3, 67.3, and 70.1, respectively in comparison to acarbose (reference α-amylase inhibitor). Additionally, their structure-activity relationship has been discussed.     

Neolignans from stem bark of ocotea veraguensis

The stem bark of Ocotea veraguensis has yielded nine neolignans of which five appear to be novel. The new neolignans, which were identified on the basis of spectral characteristics, are^* (7S,8R,1′S,2′S,3′R,4′S)-Δ^8′-2′,4′-dihydroxy-3,3′5′-trimethoxy-4,5-methylenedioxy-1′,2′,3′,4′-tetrahydro-7.3′,8.1′-neolignan, (7S,8R,1′S,3′S,4′S)-Δ^8′-4,4'-dihydroxy-3,3′,5′-trimethoxy-1′,2′,3′,4′-tetrahydro-2′-oxo-7.3′,8.1′-neolignan, (7S,8S,1′R)-Δ^8′-3′,5′-dimethoxy-3,4-methylenedioxy-1′,4′-dihydro-4′-oxo-7.0.2′,8.1′-neolignan, (7S,8S,1′R )-Δ^8′-1′-methoxy-3,4-methylenedioxy-1′,6′-dihydro-6′-oxo-7.0.4′,8.3′-neolignan and (7S,8S)-Δ^8′-2′,6′-dimethoxy-3,4-methylenedioxy-7.0.3′,8.4′,1′.0.7′-neolignan.     

Hepatoprotective activity of LC–ESI-MS standardized Iris spuria rhizome extract on its main bioactive constituents

The study was designed to evaluate the hepatoprotective activity of Iris spuria against paracetamol induced toxicity at two different doses 100 and 200 mg/kg. The extract showed significant protective activity (p > 0.01) at both the doses in dose dependent manner. Administration of the plant extract restored the paracetamol induced elevated levels of serum marker and distorted hepatic tissue architecture. The lipid peroxides (LPO) and glutathione (GSH) levels were also restored towards normal in liver tissue significantly. The main chemical constituents of the extract identified by the liquid chromatography–tandem mass spectrometry (LC–ESI-MSMS) were found to be flavones and isoflavonoids. Tectoridin and iristectorigenin A were the principal compounds present in the methanolic extract of Iris spuria.     

Four new C-glycosylflavones from the leaves of Iris lactea Pall. var. chinensis (Fisch.) Koidz.

Four new acylated C-glycosylflavones, termed embinins A–C and irislactin C, were isolated from the leaves of Iris lactea and their structures were elucidated by extensive NMR experiments and mass spectrometry studies. Embinin A and irislactin C showed weak cytotoxicity against A549 (human lung cancer) cells.     

Minor Carotenoid Sulfates from lanthella basta

The structural elucidation of the minor carotenoid sulfates from the marine sponge lanthella basta is discussed in context with the structure assigned to the major sulfate bastaxanthin (c; 3,19,17′-trihydroxy-7,8-didehydro-β-κ-carotene-3′,6′-dione 3-sulfate. Plausible structures are assigned to other bastaxanthins (b,b₂, c₂, d, e and f) on the basis of electroic, IR, ¹H NMR, mass and CD spectra, electrophoretic behaviour, chemical derivatization and enzymatic or acid-catalysed hydrolysis. The minor sulfates represent structural variation in the cylopentane end group with different oxidation levels. Bastaxanthol b (desulfated bastaxanthin b) was a minor carotenoid constituent of l. basta. Including tentative chiralities, the structures favoured for the bastaxanthins are: c₂, (3R,3′R, 5′R)-3,19,3′-trihydroxy-7,8-didehydro-β,κ-caroten-6′-one 3-sulfate; b₂, (3R,3′R,5′R)-3, 19-dihydroxy-7,8-didehydro-β,κ- dione 3-sulfate; b, (3R,1′R, 5′R)-3, 19-dihydroxy 3′,6′-dioxo-7,8-didehydro-β,κ-caroten-17′-al 3-sulfate; d. (3R,1′R,3′R,5′R)-3, 19,3′,17′-tetrahydroxy 7,8 didehydro-β,κ-caroten-6′-one 3-sulfate; e. hydrogen (3R,1′R,5′R)-3, 19-dihydroxy-3′,6′-dioxo-7,8-didehydro-β,κ-caroten-17′-oate 3 sulfate (?); and f, hydrogen (3R.1′R,3′R,5′R)-3,19,3′-trihydroxy-7,8-didehydro-6′-oxo-β,κ-caroten-17′-oate 3-sulfate; for bastaxanthol b(3R.1′R.5′R)-3, 19-dihydroxy-3′,6′-dioxo-7,8-didehydro-β,κ-caroten-17′-al. The bastaxanthins are considered as metabolic products of l. basta, diadinoxanthin of phytoplankton origin representing a plausiable precursor.     

Absolute configuration of heteroxanthin and diadinoxanthin

The absolute configurations of heteroxanthin ((3S,5S,6S,3′R)- 7′,8′-didehydro-5,6-dihydro-β,β-carotene-3,5,3′,6′-tetrol) ex Euglena gracilis and of diadinoxanthin ((3S,5R,6S,3′R)-5,6-epoxy-7′,8′-didehydro-5,6-dihydro-β,β-carotene-3,3′-diol) from the same source have been established by chemical reactions, hydrogen bonding studies, ¹H NMR and CD. Two previously unknown carotenoids (artefacts?) from Trollius europaeus, assigned the structures (3S,5S,6S,3′S,5′R,6′R)-6,7-didehydro-5,6,5′,6′-tetrahydro-β,β -carotene-3,5,6,3′,5′-pentol and its 5R epimer, served as useful models.     

Occurrence of juvabione-type and epijuvabione-type sesquiterpenoids in Abies alba

The petrol-soluble fractions from the branchwood of four Abies alba trees were examined. Only two trees contained sufficient amounts of ‘juvabione-type’ insect juvenile hormone analogues for isolation and characterization. The first contained juvabione (4R, 1′R), 4′-dehydrojuvabione (4R, 1′R) and its 4R, 1′S diastereomer in a ratio of 3:1, and juvabiol (4R, 1′R, 3′S), isojuvabiol (4R, 1′R, 3′R) and epijuvabiol (4R, 1′S, 3′S) in an approximate ratio of 7:3:2. 4′-Dehydroepijuvabione (4R, 1′S) was the only ‘juvabione-type’ compound ioslated from the second tree. If it is accepted that juvabione and epijuvabione are enzymatically reduced forms of dehydrojuvabione and dehydroepijuvabione, respectively; then for these two A. alba our results indicate that only one enzyme which is specific for R chirality at C-1′ is present, since epijuvabione is not observed.     

Configurational studies on red algae carotenoids

The configurations of (6′R)-β,ε-carotene, (3′R,6′R)-β,ε-caroten-3′-ol (α-cryptoxanthin), (3R,3′R,6′R)-β,ε-carotene-3,3′-diol (lutein), (3R)-β,β-caroten-3-ol (β-cryptoxanthin), (3R,3′R)-β,β-carotene-3,3′-diol (zeaxanthin) and all-trans (3S,5R,6S,3′R)-5,6-epoxy-5,6-dihydro-β,β-carotene-3,3′-diol (antheraxanthin) were established by CD and ¹H NMR studies. The red algal carotenoids consequently possessed chiralities at each chiral center (C-3, C-5, C-6, C-3′, C-6′), corresponding to the chiralities established for the same carotenoids in higher plants. Two post mortem artifacts from Erythrotrichia carnea were assigned the chiral structures (3S,5R,8R,3′R)-5,8-epoxy-5,8-dihydro-β,β-carotene-3,3′-diol [(8R)-mutatoxanthin] and (3S,5R,8S,3′R)-5,8-epoxy-5,8-dihydro-β,β-carotene-3,3′-diol [(8S)-mutatoxanthin]. This is the first well documented report of a naturally occurring β,ε-caroten-3′-ol (¹H NMR, CD, chemical derivatization).     

Isolation and structural elucidation of cucurbitaxanthin a and b from pumpkin cucurbita maxima

Two new carotenoids, cucurbitaxanthin A [(3S,5R,6,R3′R)-3,6-epoxy-5,6-dihydro-β,β-carotene-5,3′-diol] and cucurbitaxanthin B [(3S,5R,6R,3′S,5′R,6′S)-3,6,5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β-β-carotene-5,3′-diol] have been isolated from the pumpkin Cucurbita maxima.     

A steady-state kinetic study of the ribonuclease A catalyzed hydrolysis of uridine-2′:3′(cyclic)-5′-diphosphate

Initial velocity measurements were made on the ribonuclease A catalyzed hydrolysis of P-5′-Urd-2′:3′-P in the pH range 4.0–8.0 at 25 °C in 0.1 m Tris-acetate/0.1 m KCl. The pH dependence of the Michaelis constant, K_m, the turnover number k_s, and $\text{k}{}_{\mathrm{s}}\text{K}{}_{\mathrm{m}}$ for P-5′-Urd-2′:3′-P were similar to those reported for Urd-2′:3′-P (5). When P-5′-Urd-2,3-P and Urd-2′:3′-P were compared under similar conditions the average difference in k_s and K_m indicated that these parameters were 5-fold and 23-fold lower, respectively, for P-5′-Urd-2′:3′-P. The slight difference in the pH dependence of $\text{k}{}_{\mathrm{s}}\text{K}{}_{\mathrm{m}}$ for these two substrates can be interpreted in terms of a specific interaction of the enzyme at the 5′ position of P-5′-Urd-2′:3′-P, which permits a less exclusive dependence on the ionized state of the free enzyme in binding this substrate. The nature of the interaction of the substrate 5′-phosphomonoester group with the enzyme is discussed in terms of possible interactions with Lys-41 and His-119.     

Comparison of fungal communities among ten macrophyte rhizospheres

The fungal community composition, size and several physico-chemical properties were individually investigated in ten macrophyte rhizospheric substrates using nested PCR-denaturing gradient gel electrophoresis and soil chemical methods. Results indicated that both Dothideomycetes and Sordariomycetes were dominant fungi in macrophyte rhizospheric substrates, and denitrifying fungi (Fusarium graminearum) was found in nine of ten macrophyte rhizospheres. Fungal Shannon-Wiener diversity index (H) and richness (S) in Thalia dealbata, Typha latifolia, Iris hexagona and Hemerocallis aurantiaca rhizospheres were higher than those in other six rhizospheres. Fungal number and biomass were 1.91 × 10³ CFUs g^?1 dw and 1.53 μg ergosterol g^?1 dw in Iris pseudacor rhizosphere, and were greater than in other nine rhizospheres. The correlation analysis showed that fungal number and biomass significantly and positively correlated to total soil phosphorus, while fungal H and S were significantly and negatively correlated to total organic carbon. The principal components analysis (PCA) showed that the fungal community significantly divided ten macrophyte rhizospheres into four groups, showing the significant difference of fungal communities among ten rhizospheric substrates. The current study revealed for the first time the importance of rhizospheric fungal community in distinguishing macrophyte rhizospheres, thus will undoubtedly widen our insight into fungal communities in aquatic rhizospheres.