Spatial distribution patterns of Symplocos congeners in a subtropical evergreen broad-leaf forest of southern China

Studies on spatial distribution of congeneric species can supplement our understanding of species ecological processes. We analyzed population structure, spatial distribution, intra-and interspecific associations among six Symplocos tree species on a large(50 ha) plot in a subtropical, evergreen broad-leaf forest in southern China using spatial point pattern analysis methods. Our results suggested that the six Symplocos tree species were all clustered at small scales. The aggregation intensity of S. wikstroemiifolia with low abundance but relatively numerous large-diameter trees was much higher than that of the other five Symplocos species that occurred at high abundance but included few large-diameter trees. Spatial associations among the six congeners showed that 12 of 30 pairs were associated positively at small scales, and 13 of 30 pairs were unrelated. For species among different size classes, 79 of 120 pairs were not correlated, and 17 of 120 pairs were associated positively. These results showed insufficient evidence for interspecific competition and congeneric Symplocos species commonly coexist within subtropical plant communities. The spatial patterns of Symplocos species and their correlations changed with size(DBH) class and were simultaneously affected by spatial scales; the intensity of their aggregation and association decreased with increasing area of the sample plot.

Symplocosionosides A-C, Three Megastigmane Glycosides, a Neolignan Glucoside, and Symplocosins A and B, Two Triterpene Glycosyl Esters from the Leaves of <i>Symplocos cochinchinensis</i>var. <i>Philippinensis</i>

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Symplocos cochinchinensis var. philippinensis, 12 compounds were isolated. Spectroscopic analyses of compounds 1 - 3 established their structures to be megastig-mane glycosides, named symplocosionosides A-C. The absolute structure of 1 was determined by the modified Mosher’s method. Compound 4 was found to be a neolignan glucoside and named symplocosneolignan. The structures of com-pounds 5 and 6, named symplocosins A and B, were elucidated to be the saponins of hederagenin sugar esters. The structures of the remaining known compounds (7 - 12) were identified by comparison of spectroscopic data with those reported in the literature.

Preliminary Study on the Population Structure Characteristics of Symplocos in Xiaolingjiao Area of Huangshan Mountain

[Objectives] This study was conducted to understand the species diversity of plant communities in the Xiaolingjiao area of Anhui Province,and to analyze the current status of the plant resources of Symptocos.[Methods]Quadrats with a total area of 3 600 m^2 were set up in typical evergreen broad-leaved forests in the Xiaolingjiao area of Huangshan Mountain.[Results] There were 79 species of woody plants in the quadrats,belonging to 53 genera of 29 families.As seen from the age class structure,evergreen trees such as Castanopsis eyrei and Eurya nitida were growing populations,and Cyclobalanopsis glauca,Cunninghamia lanceolata,Pinus massoniana and Loropetalum chinense were declining populations.The age class structure of each species in Symplocos was of the growing type,and the various populations had not reached a stable state and would grow continuously.The communities had a tendency to develop to evergreen broad-leaved forests.[Conclusions]This study provides a scientific basis for the protection,development and utilization of Symplocos plants.

Somatic Embrygenesis of Symplocos paniculata

[Objectives]This study was conducted to provide a new way for the rapid reproduction of Symplocos paniculata.[Methods]With mature embryos of S.paniculata as explants,through the study of somatic embryogenesis,the effects of different media on the induction and differentiation of S.paniculata somatic embryos were discussed,and the somatic embryogenesis system for S.paniculata was preliminarily established.[Results]Calli suitable for somatic embryogenesis could be induced using modified MS(referred to as GMS)as the basic medium with the addition of 0.2 mg/L 6-BA and 0.1 mg/L NAA;the best medium combination for somatic embryo differentiation was GMS+0.25 mg/L 6-BA+0.15 mg/L NAA,and the differentiation rate could reach 71.99%;and plant regeneration needed to be carried out at low sugar concentrations.[Conclusions]This study provides a technical basis for resources protection,genetic transformation,artificial seed production,and large-scale development and utilization of S.paniculata.

Three new anthraquinone derivatives isolated from Symplocos racemosa and their antibiofilm activity

Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones A-C(Compounds 1-3) were isolated from Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses(UV, IR, Mass, ~1 H-and ^(13)C-NMR, and two-dimensional(2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds 1 and 3 exhibited good antibacterial activity in the concentration range of 160-83 μg·m L^(-1) against Streptococcus mutans, methicillin resistant Staphylococcus aureus and Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against Klebsiella pneumoniae.

Anti-androgenic effect of Symplocos racemosa Roxb.against letrozole induced polycystic ovary using rat model

Objective:To investigate the anti-androgenic properties of Symplocos racemosa Roxb.(S.racemosa)in the treatment of hyperandrogenemia associated polycystic ovary syndrome(PCOS)in a letrozole induced PCOS rat model.Methods:The testosterone levels were used to evaluate the anti-androgenic effect of S.racemosa in letrozole induced PCOS rats for 21 d.The low(250 mg/kg),mid(500 mg/kg)and high dose(1000 mg/kg)of S.racemosa was given to the PCOS induced rats for 15 d post letrozole induction to determine the effective dose of S.racemosa in the treatment of hyperandrogenemia associated PCOS.The hormones such as estrogen and progesterone were also assayed along with testosterone to determine the fluctuations in sex steroid levels in PCOS rats induced by letrozole.Results:S.racemosa treatment significantly decreased testosterone levels which were found to be elevated in PCOS rats induced by letrozole.S.racemosa significantly restored other blood biochemical parameters such as estrogen,progesterone and cholesterol levels.It also restored the histology of ovarian tissue.The ovarian weights and uterine weights were also significantly recovered after the S.racemosa treatment.Conclusions:The mid dose(500 mg/kg)and high dose(1000 mg/kg)of S.racemosa were found to be effective in the treatment of hyperandrogenemia in PCOS.This effect of S.racemosa was found to be comparable with clomiphene citrate.Clomiphene citrate which was being used as the major medicine in the treatment of PCOS could now be replaced with S.racemosa in the management of PCOS.

Endophytic Fungi Associated with a Holoparasitic Plant, Balanophora japonica (Balanophoraceae)

Holoparasitism is a special life cycle of flowering plants. All carbon resources are provided by photosynthetic host plants. A recent study revealed the presence of endophytic fungi in holoparasitic plants, but their ecological and evolutionary roles are still unknown. In this study, we examined endophytic fungi isolated from the holoparasitic plant Balanophora japonica (Balanophoraceae), collected from Kochi, Shikoku in western Japan. We isolated 23 fungal strains on inflorescences and tubers from three B. japonica plants at two locations and on one sample of the host plant (Symplocos lancifolia, Symplocaceae). Predominant isolates were Trichoderma-Hypocrea, Penicillium and Phialemonium. The first group was also predominant in the host plant. Fungal composition revealed in this study differed from the composition on B. harlandii or other root holoparasites with endophytic fungal (Rafflesia cantleyi) data. Those differences might be caused by various factors, including growth habits, location, phylogenetic position or host-parasite relationship.

白檀繁殖技术试验

本研究以小陇山林区白檀(Symplocos paniculata)为试验材料,研究种子繁殖出芽率及枝条扦插生根率2种繁殖方式的效果。结果表明:用沙藏和浓度为0.02%的赤霉素(GA_3)处理的种子与ABT1∶NAA∶IBA=8∶1∶2配比下处理的生根效果基本相同。沙藏的种子出苗率高于冷藏、干藏,为70%;粒径越大出苗效果最好,为76.7%;5月播种平均出苗率高于4、7月。ABT1∶NAA∶IBA=8∶1∶2配比处理下,一级侧根数、二级侧根数、粗根位置、根长、根数高于试验其他配比。