Diarylpropanes from Iryanthera coriacea

The trunk wood of Iryanthera coriacea Ducke (Myristicaceae) contains six compounds which belong to the recently discovered 1,3-diarylpropane type of flavonoids, 1-(2-hydroxy-4-methoxyphenyl)-3-(3,4-methylenedioxyphenyl)-propane, 1-(2,4-dihydroxyphenyl)-3-(3,4-methylenedioxyphenyl)-propane, 1-(4-methoxyphenyl)-3-(2-hydroxy-4,5-methylenedioxyphenyl)-propane, 1-(4-hydroxy-2-methoxy-phenyl)-3-(4-hydroxy-3-methoxyphenyl)-propane, 1-(2,4-dihydroxyphenyl)-3-(2-methoxy-4,5-methylene-dioxyphenyl)-propane, 1-(2,4-dihydroxy-3,5-methylphenyl)-3-(2-hydroxy-4,5-methylenedioxyphenyl)-propane.     

Flavonoids from Iryanthera laevis

Trunk wood of Iryanthera laevis Markgr. (Myristicaceae) contains 2′,4′-dihydroxy- 4,6′dimethoxydihydrochalcone, three 2′-hydroxy-4′,5′-methylenedioxyflavans with differently substituted A-rings (7-OH-6,8-diMe; 7-OH-5,8-diMe; 5-OH-7-OMe-6,8-diMe) and 1-(2′-hydroxy-4′-methoxy-5′-methylphenyl)-3(2″-hydroxy-4″,5″-methylenedioxphenyl)- propane, as well as three additional known diarylpropanes.     

Diarylpropanoids from Iryanthera polyneura

The trunk wood of Iryanthera polyneura Ducke (Myristicaceae) contains pinocembrin, 1-(2′,4′-dihydroxyphenyl)-3-(3″,4″-methylenedioxyphenyl)-propane, 1-(2′,4′-dihydroxy-3′-methylphenyl)-3-(2″-methoxy-4″, 5″-methylenedioxyphenyl)-propane and 4,2′,4′-trihydroxy-3-methoxydihydrochalcone.     

Diarylpropanes and lignans from Horsfieldia tetratepala

Two new diarylpropanes (1–2), four known compounds, and a new artifact, were isolated from 70% aqueous acetone extract of the twigs of Horsfieldia tetratepala. Their structures were elucidated by spectroscopic analysis. Cytotoxicity evaluation against five cancer cell lines showed that none of these compounds was cytotoxic.     

Boron impregnation treatment of Eucalyptus grandis wood

Eucalyptus grandis is suitable for small timber purposes, but its wood is reported to be non-durable and difficult to treat. Boron compounds being diffusible, and the vacuum-pressure impregnation (VPI) method being more suitable for industrial-scale treatment, the possibility of boron impregnation of partially dry to green timber was investigated using a 6% boric acid equivalent (BAE) solution of boric acid and borax in the ratio 1:1.5 under different treatment schedules. It was found that E. grandis wood, even in green condition, could be pressure treated to desired chemical dry salt retention (DSR) and penetration levels using 6% BAE solution. Up to a thickness of 50mm, in order to achieve a DSR of 5 kg/m(3) boron compounds, the desired DSR level as per the Indian Standard for perishable timbers for indoor use, it was found that neither the moisture content of wood nor the treatment schedule posed any problem as far as the treatability of E. grandis wood was concerned.     

Lipophyllic antioxidants from Iryanthera juruensis fruits

The phytochemical investigation of the hexane extract of Iryanthera juruensis (Myristicaceae) fruits led to the isolation of two tocotrienols and four lignans which exhibited antioxidant activity towards beta-carotene on TLC autographic assay. Two inactive quinones and three omega-arylalkanoic acids were also isolated. The isolates were investigated for their redox properties using cyclic voltammetry. The structure elucidation of the new compounds (one tocotrienol. one quinone and three omega-arylalkanoic acids) was based on analysis of spectroscopic data.     

Tetronic acid and diarylpropanes from Iryanthera elliptica

The trunk wood of Iryanthera elliptica Ducke (Myristicaceae) contains, besides 2-(ω-piperonyltridecyl) -4-methylidenetetronic acid (iryelliptin), three biogenetically related compounds: (±)-7,4′-dihydroxy-3′-methoxyflavan, 1-(4′-hydroxy-2′-methoxyphenyl)- 3-(4″-hydroxy-3″-methoxyphenyl)-propane and spiro-[3-methoxy-2,5-cyclohexadien-1.1′-6′,7′- dihydroxy-5′-methoxy-1′,2′,3′,4′-tetrahydronaphthalen]-4-one-(spiroelliptin). Spiroelliptin rearranges upon methylation to 2,2′-trimethylene-3,4,5,4′,5′-penta-methoxybiphenyl.     

Structural confirmation of spiroelliptin from Iryanthera elliptica by synthesis

Spiroelliptin, a spiro[cyclohexadienone-1,1′-tetralin] from Iryanthera elliptica, was synthesized by a novel process which involved the catalytic hydrogenation of the appropriate chalcone. This and other spiro[methoxycyclobexadienone-1,1′-tetralin] derivatives, obtained by the same process or by the oxidative coupling of the appropriate 1,3-diarylpropanes, were used as models in the compilation of ¹H and ¹³C NMR data allowing the recognition of three such naturally occurring structural types.     

Structure and estrogenic activity of new lignans from Iryanthera lancifolia

Five new dibenzylbutane type lignans (1-5) were isolated from the stem bark of Iryanthera lancifolia. Their structures were determined by extensive 1D and 2D NMR spectroscopic studies and chemical evidence. Seventeen of the isolated compounds were tested for their estrogenic activities in the estrogen responsive human breast cancer cell line MCF-7 BUS using the E-Screen proliferation assay. Cell proliferation was evaluated by the SRB assay to calculate the estrogenic parameters. The majority of the compounds induced a mitogenic response. This effect, given as Relative Proliferative Effect (RPE) to reference estrogen 17beta-estradiol (E(2)), ranged between 14% and 84%.     

Source-driven remobilizations of nutrients within stem wood in Eucalyptus grandis plantations

Nutrient remobilizations in tree ligneous components have been little studied in tropical forests. A complete randomized block design was installed in Brazilian eucalypt plantations to quantify the remobilizations of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) within stem wood. Three treatments were studied: control with neither K nor Na addition (C), 3 kmol ha^?1 K applied (+K), and 3 kmol ha^?1 Na applied (+Na). Biomass and nutrient contents were measured in the stem wood of eight trees destructively sampled at 1, 2, 3 and 4 years after planting in each treatment and annual rings were localized on discs of wood sampled every 3 m in half of the trees. Chemical analyses and wood density measurements were performed individually for each ring per level and per tree sampled. Nutrient remobilizations in annual rings were calculated through mass balance between two successive ages. Our results show that nutrient remobilizations within stem wood were mainly source-driven. Potassium and Na additions largely increased their concentration in the outer rings as well as the amounts remobilized in the first 2 years after the wood formation. The amount of Na remobilized in annual rings was 15 % higher in +Na than in +K the fourth year after planting despite a 34 % higher production of stem wood in +K leading to a much higher nutrient sink. A partial substitution of K by Na in the remobilizations within stem wood might contribute to enhancing Eucalyptus grandis growth in K-depleted soils.     

Properties of erythrocruorin from Cirraformia grandis

The respiratory protein erythrocruorin from the annelid worm Cirraformia grandis has been subjected to a detailed physicochemical characterization. The amino acid composition and heme content for this protein have been determined. Molecular weight measurements indicate a value of 3.0 × 10⁶ for the native species and 18,500 for the subunit. The number of subunits in the intact molecule is estimated as 162 ± 24. Oxygen binding experiments revealed a high affinity for oxygen, an unusually large Bohr effect, and little or no interaction among the heme groups in the pH range of 6.5–7.2.     

Bioactive apocarotenoids from Tectona grandis

The bioactive fractions of Tectona grandis have yielded seven apocarotenoids, two of which have been isolated for the first time as natural products (tectoionols A and B). The chemical structures were determined through 1D and 2D nuclear magnetic resonance experiments. The absolute configuration of tectoionol A was determined using a modified Mosher methodology. Some NMR assignments for the compounds 9(S)-4-oxo-7,8-dihydro-beta-ionol and 3beta-hydroxy-7,8-dihydro-beta-ionone have been corrected on the basis of g-HSQC and g-HMBC experiments. The general bioactivities of isolated compounds have been studied using etiolated wheat coleoptiles. Those compounds that presented higher levels of activity were assayed on standard target species (Lactuca sativa, Lycopersicum esculentum, Lepidium sativum and Allium cepa).     

Three putrescine bisamides from the leaves of Aglaia grandis

Three putrescine (i.e. 1,4-butanediamine) bisamides were isolated from the leaves of Aglaia grandis. Their structures were elucidated by interpretation of spectral data.     

C-methylated flavonoids from Pisonia grandis roots

Five new C-methylated flavonoids (1–5) together with seven known compounds have been isolated after chromatographic separation of the hexane and CH₂Cl₂ extracts of the roots of Pisonia grandis (Nyctaginaceae). Structural identification of the new compounds was accomplished by spectroscopic methods. The radical scavenging and antimicrobial properties of the isolates were investigated.     

The use of X-ray densitometry to evaluate the wood density profile of Tectona grandis trees growing in fast-growth plantations

Tectona grandis (teak) is an important commercial tree species that is widely used in tropical dendrochronology due to the formation of climate-sensitive annual growth rings. However, young trees growing in plantation conditions exhibit poor ring visibility during the first years of growth, limiting the dendrochronology application. In the present study, we use x-ray densitometry to determine the wood density profile between and within annual rings and at the sapwood-heartwood boundary in trees from fast-growth plantations. The resulting wood density profiles (WDP) can be categorized as uniform, stable growth, unstable growth, and false. The annual ring boundaries were indistinct in trees less than 8 years old. In mature trees, the annual ring boundaries are more defined. In relation to the sapwood-heartwood boundary, the WDP showed a decrease in the wood density; however, this decrease is influenced by the annual ring boundary when the two boundaries coincide. The identification of annual rings in trees growing in fast-growth plantations should be combined with X-ray densitometry and visual identification if wood density data are necessary for deriving other analysis, as climate change, from annual ring.     

Effects of leaf and branch removal on carbon assimilation and stem wood density of Eucalyptus grandis seedlings

The rate of leaf CO₂ assimilation (A _l) and leaf area determine the rate of canopy CO₂ assimilation (A _c) can be thought proportional to assimilate supply for growth and structural requirements of plants. Partitioning of biomass within plants and anatomy of cells within stems can determine how assimilate supply affects both stem growth and wood density. We examined the response of stem growth and wood density to reduced assimilate supply by pruning leaf area. Removing 42% of the leaf area of Eucalyptus grandis Hill ex Maiden seedlings did not stimulate leaf-level photosynthesis (A _l) or stomatal conductance, contrary to some previous studies. Canopy-level photosynthesis (A _c) was reduced by 41% immediately after pruning but due almost solely to continued production of leaves, and was only 21% lower 3 weeks later. Pruning consequently reduced seedling biomass by 24% and stem biomass by 18%. These reductions in biomass were correlated with reduced A _c. Pruning had no effect on stem height or diameter and reduced wood density to 338 kg m⁻³ compared to 366 kg m⁻³ in control seedlings. The lower wood density in pruned seedlings was associated with a 10% reduction in the thickness of fibre cell walls, and as fibre cell diameter was invariant to pruning, this resulted in smaller lumen diameters. These anatomical changes increased the ratio of cross-sectional area of lumen to area cell wall material within the wood. The results suggest changes to wood density following pruning of young eucalypt trees may be independent of tree volume and of longer duration.     

Acylated flavonol glycosides from leaves of Planchonia grandis

Three acylated flavonol glycosides have been identified from leaves of Planchonia grandis Ridley. They possess kaempferol as aglycone and two triglycosidic chains substituting hydroxyl groups at the 3- and 7-positions. The first glycosidic unit of each chain is esterified by a cis or trans p-coumaric acid. Structural elucidation was achieved by means of UV, NMR and mass spectrometry.