A new cycloartane glycoside from Camptosorus sibiricus

A new cycloartane glycoside was isolated from the whole herbs of Camptosorus sibiricus. By means of spectroscopic methods its structure was established as 3beta, 7beta, 24beta, 25, 30-pentahydroxycycloartane-24, 30-di-O-beta-D-glucopyranoside (1). proflixian@163.com     

Two new benzophenone glycosides from the fruit of Psidium guajava L.

The ripe edible fruits of Psidium guajava L. was phytochemically investigated, three benzophenone glycosides, 2, 6-dihydroxy-3, 5-dimethyl-4-O-β-D-glucopyranosyl-benzophenone (1), 2, 6-dihydroxy-3-methyl-4-O-(6″-O-galloyl-β-D-glucopyranosyl)-benzophenone (2), 2, 6-dihydroxy-3, 5-dimethyl-4-O-(6″-O-galloyl-β-D-glucopyranosyl)-benzophenone (3) were isolated by means of chromatography, and their structures were elucidated on the basis of mass spectrometry, ¹H NMR, ¹³C NMR, HSQC and HMBC data. Compounds 1 and 2 were new benzophenone glycosides, and here we report the complete spectroscopic assignments for 3.     

A new natural azulene-type pigment from Oreocnide frutescens

A new natural red-purple azulene-type pigment, 1,1,6-trimethylazuleno[1,8-cd]pyran-3(1H)-one, named oreolactone (1), together with nine known compounds, scopoletin (2), pomolic acid (3), friedelin (4), 3β-friedelinol (5), 3α-friedelinol (6), stigmast-4-en-3-one (7), stigmast-4, 22-dien-3-one (8), β-sitosterol (9), and daucosterol (10), was isolated from the rhizomes of Oreocnide frutescens. The structures were elucidated on the basis of spectroscopic analysis.     

Microenvironmental heterogeneity of physical soil properties in a broad-leaved Pinus koraiensis forest gap

Microenvironmental heterogeneity of soil physical properties in 0–20 cm and 20–40 cm soil layers in a broad-leaved Pinus koraiensis forest gap in Xiao Xing’anling Mountains were analyzed by geostatistical method. The results show that the amount of soil water, saturation water capacity, capillary water capacity and porosity in the top layer were greater than those in the lower layer, except for bulk density, where the opposite applied. Soil physical properties in the top soil layer had relatively higher ranges and coefficients of variation. The total and auto correlation spatial heterogeneity of soil physical properties in the top layer were larger than those in the lower layer. The soil water had a strong anisotropic structure in an easterly and northerly direction, but porosity shows isotropy in the same directions. With increasing spatial distance, the other three physical factors exhibited anisotropic structures. The mutual effect between semi-variograms of soil physical properties in the top layer within the spatial autocorrelation range was not significant. For spatial distribution of physical properties within different layers, the patches at the middle and lower ranks in the forest gap dominated. Patches at higher rank were only distributed in the 0–20 cm soil layer and were located north of the forest gap center. __________ Translated from Science of Soil and Water Conservation, 2007, 5(3): 52–58 [译自: 中国水土保持科学]     

Ferulic acid esters from Euphorbia hylonoma

Octacosyl cis-ferulate (1), along with the trans isomer (2), cholest-5-en-3beta-ylhexadecanoate, chrysophanol and octadecanoic acid was isolated from the roots of Euphorbia hylonoma.     

The preliminary study on juvenile-mature correlation ofPinus koraiensis

Through studying seven analytic trees from two stands ofPinus koraiensis artificial forests, the results show that the individual variation coefficient of tree heigh, dbh and volume decreases with age increasing after age of 25. Age of 25 is the age that difference of individual growth is from acute difference to comparatively stability. The optimum selection age is 25a forPinus koraiensis’s artificial forests according to the analysis of juvenile-mature correlation, and early selection efficiency. (Responsible Editor: Zhu Hong)     

2种修剪方式对红松生长量的影响

通过对红松人工林进行截顶和修枝2种修剪试验,研究不同修剪方式对红松生长量的影响,结果表明：密度适中的林分截顶后能促进林木直径的生长,试验区比对照区提高了30.8%;适当的修枝(修去枯死枝和下层1~2轮活枝)不仅可以提高林木的质量,还可以提高林木直径的生长量。     

Three new acetylated benzyl-beta-resorcylate glycosides from Cassia obtusifolia

Three new acetylated benzyl-beta-resorcylate glycosides (1-3) were isolated from seeds of Cassia obtusifolia. Their structures were determined on the basis of the spectroscopic methods and physicochemical properties as 2-benzyl-4,6-dihydroxy benzoic acid-6-O-[2,6-O-diacetyl]-d-glucopyranoside (1), 2-benzyl-4,6-dihydroxy benzoic acid-6-O-[3,6-O-diacetyl]-d-glucopyranoside (2) and 2-benzyl-4, 6-dihydroxy benzoic acid-6-O-[4,6-O-diacetyl]-d-glucopyranoside (3), respectively.     

2-aryl benzofurans and their derivatives from seeds of Styrax macranthus

Two new 2-aryl benzofuran derivatives, 3-[7-methoxy-2-(3,4-methylenedioxyphenyl) benzofuran-5-yl]propyl 3-[7-methoxy-2-(3,4-methylenedioxyphenyl)benzofuran-5-yl]propanoate (1) and demethoxy egonol gentiobioside (2), were isolated from the aqueous ethanolic extract of the seeds of Styrax macranthus, together with 7-methoxy-2-(3,4-methylenedioxyphenyl)benzofuran-5-carbaldehyde, egonol, demethoxy egonol, demethyl egonol, egonol glucoside, egonol gentiobioside, egonol gentiotrioside, stigmasterol, 2,3-dihydroxypropyl tetracosoate, and daucosterol. Their structures were elucidated on the basis of spectral and chemical evidence.     

New coumarin glycosides from Rhododendron lepidotum

Two new coumarin glycosides, named Rhodonin (1) and Rhodonetin (2) were isolated from the aerial parts of Rhododendron lepidotum.     

Tannins from barks of Pinus caribaea protect Escherichia coli cells against DNA damage induced by gamma-rays

This work was aimed to evaluate genotoxicity and antigenotoxicity activity against gamma-rays of a tannin fraction obtained from barks of Pinus caribaea, as well as to elucidate the antigenotoxic mechanisms involved in radioprotection by using different approaches as pre-, co- and post-irradiation cell treatments with plant extract. The tannin fraction was not genotoxic to Escherichia coli cells in experiments using different exposure times. This extract was antigenotoxic against gamma-rays when the cells were pre- or co-treated with this extracts, but not during post-irradiation treatments, suggesting a possibly antigenotoxic action through free radical scavenging mechanisms. The results are discussed in relation to the chemopreventive and therapeutic potential of the studied plant species.     

Two new coumarins from Euonymus hamiltonianus

Two new coumarins, named Euonidiol (1) and Euoniside (2) were isolated from the aerial parts of Euonymus hamiltonianus.     

Rainfall redistribution of a virgin Pinus koraiensis forest and secondary Betula platyphylla forest in Northeast China

A virgin Pinus koraiensis forest in the Xiaoxing’an Mountains was selected to study its rainfall redistribution effect via 97 rainfall occurrences during a growing season. The following results were obtained: 1) The canopy interception of the P. koraiensis virgin forest amounted to 98168 mm during a growing season (May to September), which was 19.6 per cent of the total rainfall and 1.3 times that of a secondary Betula platyphylla forest. Compared with other forest types in China (11.4%–36.5%), the ratio of the canopy interception in the virgin pine forest was at a medium level. 2) The throughfall of the virgin pine forest was 395.77 mm, which accounted for 78.7% of total precipitation, and the stem-flow was 8.78 mm, accounting for 1.74% of total precipitation. Compared with the secondary birch forest, the virgin pine forest had lower throughfall but higher stem-flow. 3) Cubic regression equations (p < 0.01) which describe the relation between throughfall, stem-flow and canopy interception in the virgin pine forest and rainfall in an open field were fitted. A linear regression equation (p < 0.01) was found to be a better fit for the relationship between throughfall of the secondary birch forest and rainfall outside the forest. Factors affecting throughfall and stem-flow were analyzed, with results providing a good reference to the study of rainfall redistribution in coniferous and broadleaved mixed forests. __________ Translated from Science of Soil and Water Conservation, 2006, 4(6): 61–65 [译自: 中国水土保持科学]     

Soil properties in forest gaps and under canopy in broad-leaved Pinus koraiensis forests in Changbai Mountainous Region, China

The species composition and diversities, and soil properties under canopy gaps in broad-leaved Pinus koraiensis forests were studied in the Changbai Mountains. The results indicated that the species composition and diversities in gap were different from those under canopy. The Shannon-Wiener index, evenness index, and abundance index in gap were higher than those under canopy in the seedling layer, while the community dominance in the seedling layer increased in closed canopy. The physicochemical properties of soil changed with the change of space and resource availability in gaps. The thickness, standing crop, and water holding capacity of the litter layer under canopy were significantly (p<0.01) higher than those in gap. The content of total nitrogen and total potassium of litter in gap were 10.47% and 20.73% higher than those under canopy, however, the content of total phosphorus and organic carbon under canopy were 15.23% and 12.66% more than those under canopy. The water content of 0–10 cm and 10–20 cm of soil layer in gap were 17.65% and 16.17% more than those under canopy. The soil buck density of 0–10 cm were slightly higher under canopy than that in gaps, but there was no significant difference in the soil buck density of the 10–20 cm soil layer. The soil pH values were 5.80 and 5.85 in gap and under canopy, respectively, and were not significantly different. The content of soil organic matter, total nitrogen, and total potassium in gap were 12.85%, 7.67%, and 2.38% higher than those under canopy. The content of NH₄ ⁺-N, available phosphorus, available potassium, and total phosphorus in soil under canopy were 13.33%, 20.04%, 16.52%, and 4.30% higher than those in gap. __________ Translated from Forest Research, 2006, 19(3): 347–352 [译自: 林业科学研究]     

A new triterpenoidal ester from Celastrus rosthornianus

3-O-Palmitate of 1beta, 3beta, 11beta-trihydroxy-olean-12-ene (1),was isolated from the stalks of Celastrus rosthornianus. The structure was elucidated by MS, 1D- and 2D-NMR experiments as well as by chemical degradation.     

A new cerebroside from Gynura divaricata

A new cerebroside, 1-O-β-d-glucopyranosyl-(2S,3S,4R,10E)-2-[(2′R)-2′-hydroxyltricosanoyl-amino]-10-octadecene-1,3,4-triol was isolated from the aerial parts of Gynura divaricata DC.     

A new phytosterone from the roots of Achyranthes bidentata

A new phytosterone, (20R, 22R)-2beta, 3beta, 20, 22, 26-pentahydroxy-cholestan-7,12-dien-6-one (1), was isolated from the roots of Achyranthes bidentata. The structure was elucidated on the basis of spectral data.     

Fallen wood decomposition ofPinus koraiensis andTilia amurensis

Fallen wood decomposition rate ofPinus koraiensis andTilia amurensis in broadleaved Korean pine forest was studied in this paper. The result showed that decomposition rate of fallen wood was different from that of little diameter wood and coarse woody debris for the same tree species. Fallen wood decomposition was generally rotten from outside to inside. And decomposition speed of fallen woods was different according to tree species and site, and it was also related to diameter of fallen woods. Decomposition depth ofTilia amurensis fallen wood for 17 years was 14 cm, but that ofPinus koraiensis in the same condition was less than 7 cm.Tilia amurensis was decomposed faster thanPinus koraiensis. For same tree species, if the diameter was small, the decomposition speed was quick. This project was supported by Natural Science Foundation of China (No. 39670144) and funded by the Opened Research Station of Changhai Mountain Forest Ecosystem, Chinese Academy of Sciences. (Responsible editor: Zhu Hong)     

A new phenolic glycoside from the aerial parts of Dryopteris fragrans

A new phenolic glycoside, 3,5-dimethyl-6-hydroxy-2-methoxy-4-O-D-glucopyranosyl-oxy-acetophenone (1), was isolated from the aerial parts of Dryopteris fragrans. The structure was elucidated on the basis of spectroscopic methods.     

Study on improving the growth quality of planted seedling ofPinus koraiensis in initial stage

Each link in initial process of artificial regeneration ofPinus koraiensis in clear cutting site was researched. The seedling recovery processes after transplantation, the affecting seedlings survival factors in different time, and the characters of seedling growth were analyzed. Results of this study suggest that the root recovery of Korean pine seedlings after transplanting is the key link in the artificial regeneration management. The synthetically management was proposed on basis of seedling root recovery process. The project was surpported by Natural Science Fund of Heilongjiang Province