Heartwood of Charnaecyparis obtusa contains significant amounts of a dibenzylbutyrolactone lignan, hinokinin (8). This investigation demonstrated that the contents of 8 and a norlignan, hinokiresinol (12), were higher in the heartwood region than in the sapwood, indicating their nature of being heartwood extractives. Eleven lignans -xanthoxylol (1), 7-oxohinokinin (2), savinin (3), dihydrosesamin (4), isoactifolin (5), sesamin (6), piperitol (7), hinokinin (8), pluviatolide (9), haplomyrfolin (10), and matairesinol (11) -were isolated from young shoots of Chamaecyparis obtusa cv. Breviramea. Eight lignans (1, 2, 4, 5, 7, 9, 10, and 11) were isolated from this plant for the first time. Chiral high-performance liquid chromatographic analysis showed that 8, 9, 10, and 11, were found to be levorotatory and optically pure (>99% e.e.). Based on the chemical structures of the isolated lignans, possible biosynthetic pathways of 8 are discussed.

ABSTRACT:The molecular morphology of lignophenol and conventional lignins were analyzed with SEC-MALLS system. MALLS analysis has been used as method for absolute molecular weight of polymers. However determination of absolute molecular weight of lignin is difficult due to divisively and complication of lignin structure. But the difference in the molecular weight of lignin determined by MALLS and conventional calibration methods using linear polystyrene standard can show the difference of molecular morphology of lignin. Lignin is the most abundant natural aromatic network polymer and exists in plant cell walls as one of the major constituents. It serves as a cement between wood fibers, as a stiffening agent within fibers, and as a barrier to the enzymatic degradation of the cell wall, because pulp delignificated pulp is easily resolved by the microorganism. But lignin-based products have scarcely been in human life in spite of the importance in nature. This phenomenon is due to complex structure of lignin. Lignins are three-dimensional network polymers of phenylpropane units with many different linkages between the monomers leading to a complicated structure that can only be defined by the frequency of occurrence of the various linkages. This random structure arises from an enzymatically initiated free radical polymerization of lignin precursors in the form of p-hydroxycinnamyl alcohols.1-3 Furthermore, non-selective modifications of the lignin structure are caused by different ways due to the conditions for isolation from the cell wall. The control of structure is necessary to utilize lignin based polymer as functional polymer.Recently Lignin-based functional polymer (lignophenol) were derived from native lignins through the phase-separation process. [4][5][6][7] This process includes a phase-separattion reaction system composed of phenol derivatives and concentrated acid. In the process the concentrated acid is a solvent for carbohydrate and act as a catalyst for the hydrolysis of carbohydrate, but also works as a catalyst for the fragmentation and phenolation of lignin, whereas phenol derivatives act as phenolation agents, a barrier to minimize the attack of acid on the lignin and a solvent for the lignin fractions. The lignin derivatives (lignophenol) have several unique functions, which conventional lignins do not have, in spite of retention of the original interunit linkages, for example, solid-liquid transformation and high immobilization capability for proteins (enzyme). 7 It is thought that the cause of these unique functions of lignophenol is attribute to molecular morphology of lignophenol. In the present paper, we attempted comparison of molecular morphology of lignophenol and conventional lignins by molecular weight measurement with the on-line combination analysis of size exclusion chromatography (SEC) and multi-angle laser light scattering (MALLS).In an early review, Goring described the applicability of a number of different analytical methods employed to determine the average molecular weight of...

Lignin is one of the components in the plant cell wall, after cellulose, making up 20-30% of the global plant biomass. Lignophenols (LPs) are derivatives of lignin with high phenolic function and antioxidant properties. However, their medicinal property is not well characterised. Apolipoprotein-B (apo-B) is an essential component in very low-density lipoprotein, and high levels of serum apolipoprotein-B (apo-B) are a major factor for coronary heart disease. In this study, we examined the effect of lignophenols on apo-B secretion in HepG2 cells. HepG2 cells were treated with varying concentrations of LPs and 0.8 mM sodium oleate. LPs decreased oleate-induced apo-B secretion in a dose-dependent manner. LPs also decreased oleate-induced microsomal triglyceride transfer protein (MTTP) mRNA expression and cellular total cholesterol, suggesting that lipid bioavailability and lipidation of lipoprotein are likely involved in the decreased secretion of apo-B. Furthermore, LPs decreased oleate-induced mature sterol regulatory element binding protein 2 (SREBP-2), a transcription factor that activates cholesterol biosynthesis. This is the first study to show that LPs can decrease oleate-induced apo-B secretion in HepG2 cells. The modulations of MTTP mRNA expression, cellular total cholesterol metabolism and mature SREBP-2 expression may be important factors in the regulation of apo-B secretion by LPs.Coronary heart disease is a leading cause of death. High prevalence and death rate have spurred the search for novel strategies to prevent coronary heart disease. Apolipoprotein-B (apo-B) is an essential component in very low-density lipoprotein, and its blood level is positively correlated with the incidence of coronary heart disease and atherosclerosis [1]. To meet the public demand for primary prevention of coronary heart disease, medicinal substances that control the rate of apo-B secretion are of great interest.Lignin constitutes 20-30% of woody plant cell walls. Following cellulose, lignin is the second most abundant biopolymer on earth [2]. An original reaction system, a phase-separation system, was developed for the production of lignophenols (LPs) from native lignin [3]. Although LPs have been reported to possess highly phenolic functions, high stability and antioxidative properties in vitro [4], their medicinal properties have remained unclear. Recently, an LPs from bamboo has been reported to prevent hydrogen peroxideinduced cell death in vitro [5]. We have also reported the protective effect of LPs from Beech (Fagus crenata Blume) on copper-and zinc-mediated cell death in rat pheochromocytoma (PC12) cells [6]. However, to the best of our knowledge, no previous study has examined the physiological effects of LPs on lipid metabolism.Several antioxidative polyphenols such as epigallocatechin gallate [7], quercetin [8] and curcumin [9] have been reported to moderately decrease apo-B secretion. Since LPs have also been reported to possess high phenolic function and antioxidant properties in vitro [4], we invest...

ABSTRACT:A polymer structure and function of lignophenol was examined by various structural analysis of lignophenols fractionated with preparative SEC. The base unit of lignophenol is 1,1-bis (aryl) propane-2-O-aryl ether unit in all the molecular weight areas by NMR analysis. But the amounts of combined cresol and phenolic hydroxyl groups were increased with decreasing molecular weight of fractionated lignophenols. The protein-adsorbing capacities and thermoplastic property of fractionated lignophenols differed with the molecular weights.[doi:10.1295/polymj.PJ2005142] KEY WORDS Lignin / Fractionation / Molecular Weight / Polymer Structure / Phase-separation System / Lignophenol / Lignin is the most abundant natural polymer next to cellulose and exists in plant cell walls as one of the major constituents. However, in contrast to the importance and potential of lignin in nature, lignin-based products have scarcely been in human life. This strange phenomenon is due to complicated structure and reactivity of lignin. Lignin is biosynthesized via random radical coupling of p-hydroxycinnamyl alcohols, which is initiated by enzymatic one-electron oxidation of phenolic hydroxyl groups.1,2 Thus lignin has a variety of inter-unit linkage and an amorphous three-dimensional network polymer.3,4 Furthermore, complicated modifications of the lignin structure are caused through isolation process from the cell wall. Presently kraft lignin which is the most abundant commercial lignin can be produced mainly as byproducts in kraft pulping process. However the lignin from kraft pulping process are burned for the production of energy for pulping process, so they are not utilized as raw materials for chemicals. In order to utilize the kraft lignin as more valuable materials, the conversion of kraft lignin to functional polymers has been attempted by many researchers, 5-8 but any industrial use of the lignin has not been accomplished. Therefore it is difficult to change highly modified lignin into functional polymers.Recently lignin-based functional polymer (lignophenols) has originally been designed and their synthesis process from native lignin (original lignin in wood) has been developed. 9 This process includes the phase-separation reaction system composed of phenol derivatives and concentrated acid. In the process, native lignin was modified by selectively grafting phenol derivatives to benzyl position, the most reactive sites, to give lignophenols that remain the original interunit linkage of lignin and have high phenolic content (Scheme 1).The lignophenols have several unique functions, for example lignophenols indicate an apparent solidliquid transformation at ca. 130 C in hardwood and at ca. 170 C in softwood, and high immobilization capability for proteins (enzyme). 10,11 In this study, the correlation between these unique functions of lignophenols and polymer structures were investigated. EXPERIMENTAL Wood and Lignin PreparationsAir-dried wood samples were ground to pass an 80 mesh screen and extracted with ethanol-benzene (...

Lignophenols (LP) are the derivatives of native lignin, which is an abundant organic polymer in the plant kingdom. This study investigated whether LP can attenuate vascular oxidative stress and inflammation in streptozotocin (STZ)-induced diabetic rats. The diabetic rats induced by a single intravenous injection of STZ were randomly divided into two groups fed either 0 or 1.0% LP-containing diet. After 5 weeks of treatment, the superoxide (O(2)(-)) production, mRNA expression levels of nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidase subunits, monocyte chemoattractant protein-1 (MCP-1) and its receptor C-C chemokine receptor 2 (CCR2), and protein expression level of inducible nitric oxide synthase (iNOS) were examined in the aorta of vehicle-injected control and diabetic rats treated with or without LP. The increased O(2)(-) production and mRNA expression levels of NAD(P)H oxidase subunits Nox4 and p47phox were found to be significantly reduced in the aorta of diabetic rats treated with LP. The mRNA expression of MCP-1 and CCR2, and the protein expression of iNOS were found to be increased in the aorta of untreated diabetic rats, whereas these levels were significantly lower in the LP-treated group. These findings suggest that LP could attenuate vascular oxidative stress and/or inflammation via inhibition of NAD(P)H oxidase. This may lead to an improvement in the vascular impairment of diabetes.