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The norlignan (NorL) content in extractives of sugi (Cryptomeria japonica) shows a decreasing tendency from the outer to the inner part of the heartwood (hW). The hypothesis, that this effect may be due to polymerization, which aggravates NorL extraction, has been explored in the present study. To this purpose, samples were collected and extracted from the outer, middle and inner parts of the hW. Fractionation procedures of NorL-oligomers by LH-20 column chromatography were established, and the fractions were characterized by advanced analytical methods such as HPLC-SEC and HPLC combined with electrospray ionization ion trap mass spectrometry (HPLC-ESI-ion-trap-MS). Agatharesinol and sequirin C were the most abundant compounds. Several individual NorL-dimers and -trimers were detected for the first time, and four kinds of NorL-dimers and seven kinds of NorLtrimers were semi-quantitatively analyzed by HPLC-ESIMS combined with selected ion monitoring (SIM). The oligomer contents show an increasing tendency from the outer part toward the middle and inner part of the hW, which accounts mainly for the monomeric NorL decrement in the same direction. [ABSTRACT FROM AUTHOR]

Abstract  Heartwood extracts from Amazonian trees cumaru-ferro (Dipteryx odorata), jatoba (Hymenaea courbaril), and guarita (Astronium lecointei) exhibit antioxidant activities comparable with that of α-tocopherol, a well-known antioxidant. This article reports the characterization of the antioxidant compounds in the extracts of the three heartwoods. Silica gel column chromatography of the cumaru-ferro EtOAc extract yielded (−)-(3R)-7,2′,3′-trihydroxy-4′-methoxyisoflavan and (+)-(3R)-8,2′,3′-trihydroxy-7,4′-dimethoxyisoflavan. Silica gel column chromatography followed by preparative high-performance liquid chromatography of the jatoba EtOAc extract yielded (−)-fisetinidol and (+)-trans-taxifolin. Chemical structures were assigned using electron-ionization mass spectrometry, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy including nuclear Overhauser effect spectroscopy (NOESY), as well as optical rotation and circular dichroism. Gas chromatography-mass spectrometry demonstrated that the isolated compounds were predominant in the EtOAc extracts. In the guarita EtOAc extract, catechin and gallic acid were identified by comparing their retention times and mass fragmentation patterns with those of authentic samples. Antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl assay demonstrated that all these compounds had activities comparable with that of α-tocopherol. [ABSTRACT FROM AUTHOR]

Abstract  The heartwood and sapwood characteristics of 11 Amazonian trees were investigated. Whereas 7 of the specimens had densities greater than 0.7 g/cm3, the heartwood density of ipê amarelo (Tabebuia serratifolia), maçaranduba (Manilkara huberi), cumaru-ferro (Dipteryx odorata), and guarita (Astronium lecointei) exceeded 1.0 g/cm3. Jatobá contained small amounts of Klason lignin and α-cellulose, and large amounts of holocellulose and alkali extract, suggesting that it has a high polysaccharide content that can be dissolved in an alkaline medium. The difference in the syringyl/guaiacyl (S/G) ratios of the samples before and after alkali extraction suggests that alkali extracts contain syringyl-type polyphenols. In all of the samples, the heart-wood methanol extracts were larger in volume than the sapwood methanol extracts, and the sapwood alkali extracts were larger in volume than the heartwood alkali extracts. The antioxidant activities of the methanol and alkali extracts were assayed by measuring the levels of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and super oxide dismutase (SOD)-like activity, respectively. The heart-wood methanol extract of jatobá (Hymenaea courbaril) exhibited the highest level of activity (EC50 = 44 mg/l), which exceeded that of α-tocopherol (EC50 = 48 mg/l), and the heartwood alkali extracts of jatobá and ipê amarelo had high SOD-like activity comparable with red wine. [ABSTRACT FROM AUTHOR]

Abstract??To study the behavior of hardwood sulfuric acid lignin (SAL) during phenolization, we compared the product yield, average molecular weight, methoxy content, and reactions of simple model compounds with those of softwood SAL, focusing on the difference between syringyl and guaiacyl units. The beech SAL reacted with phenol more readily than red pine SAL and yielded a larger soluble fraction of phenolized SAL. To investigate the difference in the phenolization activity of the syringyl and guaiacyl units in beech lignin, we prepared syringyl-nucleus-rich sulfuric acid lignin (S-rich-SAL) and guaiacyl-nucleus-rich sulfuric acid lignin (G-rich-SAL) from beech, which were subjected to phenolization. The results suggest that the syringyl unit in SAL had greater phenolization activity and its phenolized products were more soluble in acidic aqueous medium and introduced less phenol than the guaiacyl unit. Using model compounds, the study also showed that the syringyl unit had higher phenolization reactivity than the guaiacyl unit. [ABSTRACT FROM AUTHOR]

Matairesinol and pinoresinol were isolated from sugisapwood 40 days after felling. These lignans were not detected in the heartwood. Accordingly, they are probably the result of post-mortem biosynthesis in sapwood parenchyma cells. [ABSTRACT FROM AUTHOR]