Isoflavones and stilbenes of the heartwood ofMaackia amurensis

The isoflavin retusin, squalene, 3,4′,5-trihydroxystilbene (resveratrol), 3,3′,4′,5-tetrahydroxystilbene, and a new compound constructed of fragments of retusin and 3,3′,4′,5-tetrahydroxystilbene have been isolated for the first time from an ethanolic extract of the heartwood ofMaackia amurensis Rupr. et Maxim (Fabaceae) growing in Maritime Territory. The high-molecular-weight polyphenols that impart the characteristic coloration to macckia wood are present in an amount of 7%. The majority of the phenolic compounds isolated showed a high antiradical and antioxidant activity.     

Phenolic compounds of the bark of Syringa amurensis

Chemistry of Natural Compounds -     

Isoflavonoids from Heartwood of Maackia amurensis Rupr. et Maxim.

Orobol, tektorigenin, (-)-medicarpin, (±)-vestitol, and a new isoflavanone, the structure of which was established by chemical transformations and spectral data, were isolated from heartwood ofMaackia amurensis     

Isoflavonoids of the leguminosae

Isoflavonoids are found predominantly in subfamily Papilionoideae of the Leguminosae. This review describes more than 420 new examples of Leguminosae isoflavonoids, giving details of their source, identification, biological activity, synthesis, and ecological or chemosystematic significance. Other topics addressed include the application of hyphenated analytical techniques to the characterisation of legume-derived isoflavonoids, and advances made in biosynthetic studies. A checklist of new compounds by species is given, and 404 references are cited.     

Chemical constituents from leaves and trunk bark of Rinorea oblongifolia (Violaceae)

Abstract

Two new coruleoellagic acid derivatives, 3,4′,5,5′,-tetramethylcoruleoellagic acid (1); 3′,4,4′,5,5′-pentamethylcoruleoellagic acid (2) and a new friedelane-type triterpene derivative rinol (5), were isolated from leaves and trunk bark of Rinorea oblongifolia (Violaceae) along with seven known compounds including 3,3′,4,4′,5′-pentamethylcoruleoellagic acid (3), hexamethylcoruleoellagic acid (4), 28-hydroxyfriedelin (6), friedelin (7), friedelan-3-ol (8), scopoletin (9) and β-sitosterol-3-O-β-D-glucopyranoside (10). Their structures were elucidated by means of spectroscopic methods including IR, 1D and 2D NMR in conjunction with mass spectrometry. Crude extracts of leaves and trunk bark as well as compounds 1–4 were evaluated for their antibacterial activities against 7 pathogenic bacterial strains (Streptococcus pneumoniae ATCC49619, Staphylococcus aureus ATCC 43300, Klepsiella pneumoniae ATCC 700603, Haemophilus influenza ATCC 49247, Escherichia coli ATCC 25922, Pseudomonas aeruginosa HM601, Staphylococcus aureus BAA 977). Compound (3) displayed noteworthy activity against Haemophilus influenza with MIC value of 9.38?µg/mL.     

Antimicrobial and cytotoxic activities of leaves, twigs and stem bark of Scutia buxifolia Reissek

The antimicrobial and cytotoxic activities of the dichloromethane, ethyl acetate and butanolic fractions from the leaves, twigs and stem bark of Scutia buxifolia were evaluated using the broth microdilution method and the brine shrimp lethality method, respectively. Phytochemical analysis was performed by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The antimicrobial results demonstrated that the strongest effect occurred with the butanol fraction from the twigs and the ethyl acetate fraction from the stem bark against Saccharomyces cerevisiae (minimal inhibitory concentration; MIC?=?62.5?μg?mL(-1)), whereas the ethyl acetate and butanolic fractions from the twigs and stem bark were effective against Pseudomonas aeruginosa and Staphylococcus aureus, with MIC values ranging from 125 to 500?μg?mL(-1). LD(50) values varied from 50.00?±?0.22 to 82.23?±?0.34?μg?mL(-1). Quercetin, quercitrin, isoquercitrin and rutin were identified by HPLC and may be partially responsible for the antimicrobial activities observed. This study reports for the first time the antimicrobial and cytotoxic activities of S. buxifolia leaves, twigs and stem bark.     

Gel permeation chromatographic study of the molecular weight distribution of tannins in the wood,bark and leaves ofEucalyptus spp.

Summary The molecular weight distribution of tannins from the wood, bark and leaves ofEucalyptus camaldulensis, E. globulus andE. rudis from two different Spanish provenances has been studied by high performance gel permeation chromatography, using the compounds' acetylated derivatives. The MW distribution profiles showed important variability depending on the type of vegetal tissue, the species and, in some cases, on the geographical provenance of the samples. Bark was the vegetal tissue that yielded tannins with the highest molecular weight, followed by wood and leaves. Tannins from wood and bark ofE. camaldulensis were of higher molecular size than those fromE. globulus andE. rudis; those in the leaves ofE. globulus andE. camaldulensis were similar in molecular size and larger than those in the leaves ofE. rudis.     

Analysis of tree leaves,bark and wood by sequential inductively coupled argon plasma atomic emission spectrometry

The analysis of extracts from tree leaf, bark and wood samples for Ca, Mg, K, Na, P, Mn, Fe, Al, B, Cu and Zn by inductively coupled argon plasma sequential emission spectrometry is described. Recovery percentages for simulated tree extracts and for spiked tree samples are presented together with typical analysis values for a leaf and a wood sample. The choice of analytical line for each element is discussed and spectral interferences, not listed in the ICP tables of Boumans, of Cu on the 214.9 nm line of P and of Fe on the 249.7 nm line of B are noted.     

Three New Isoflavonoids from the Aerial Parts of Ammopiptanthus mongolicus

Three new isoflavonoids, namely (±)‐ammopiptanine A ( 1 ), ammopiptanine B ( 2 ), ammopiptanoside A ( 3 ), together with 13 known compounds, were isolated from the aerial parts of Ammopiptanthus mongolicus. Their structures were elucidated on the basis of detailed spectroscopic analyses and by comparison with those of related model compounds. The isoflavonoids described, except formononetin, wistin, daidzein, and calycosin, were isolated from this plant for the first time.     

Comparison of the essential oils of leaves and stem bark from two different populations of Drimys winteri a Chilean herbal medicine

The chemical composition of the essential oils obtained by hydrodistillation of stem bark and leaves of Drimys winteri J.R. et G. Foster var. chilensis /DC A. Gray (Winteraceae) from Chiloe Island (ID) and Continental Chile (Santiago) (CD) were studied by GC and GC/MS. Sesquiterpene hydrocarbons constituted the main chemical groups in the stem bark oils, with alpha-santalene, trans-beta-bergamotene and curcumenes as the major components. Monoterpenes constituted the main chemical groups in the leaves of Island plants with alpha-pinene (23.1%) beta-pinene (43.6%) and linalool (10.5%) as the main components whereas sesquiterpenes (germacrene D 17.6%) and phenylpropanoids (safrole 20.8%) are the most abundant in the leaves of Continental plants.     

Synthesis of Analogs of Natural Isoflavonoids Containing Phloroglucinol

Analogs of the natural isoflavonoids biochanin A and orobol were synthesized. Alkylation involving phenolic hydroxyls and the chromone ring was studied.     

葛根异黄酮成分的加压溶剂提取法研究

优化了中药葛根异黄酮类成分加压溶剂提取的条件。采用高效液相色谱法同时测定葛根提取液中葛根索、大豆苷和大豆苷元含量,以三者含量总和为评价指标,以用正交设计的考察方式对影响加压溶剂提取葛根异黄酮类成分的因数进行优化。优选出最佳提取条件：溶剂为甲醇;温度140℃;提取时间10min;压力8．27MPa,置换体积为60％,并与葛根药典提取方法进行比较,结果表明：加压溶剂提取法具有提取时间短、溶剂消耗少、提取效率高、重现性好、操作模式多样化以及操作过程自动化等优点,将有助于中药质量控制提取过程的标准化。