小果南烛三萜类化学成分研究

羊毛甾烷三萜是南烛属植物主要活性成分之一。为进一步研究南烛属植物功效物质基础,结合民族民间对小果南烛的应用实际,该文利用硅胶、MCI、Sephadex LH-20、半制备高效液相色谱等植物化学技术手段对该植物95%乙醇提取物进行分离、纯化,综合理化性质和波谱数据对其化合物进行鉴定。结果表明:从小果南烛的茎、叶提取物中分离得到14个三萜及其皂苷,分别鉴定为mollic acid 3-O-α-Larabinopyranoside (1)、mollic acid 3-O-β-D-glucopyranoside (2)、cycloart-3,7-dihydroxy-24-en-28-oic acid (3)、白桦脂酸(4)、1β,3α,11α-trihydroxy-urs-12-ene (5)、oleanderolide (6)、(Z)-马斯里酸-3-O-对香豆酸酯(7)、木栓酮(8)、坡模酸(9)、2α,3α-二羟基乌苏-12-烯-28-酸(10)、科罗索酸(11)、齐墩果酸(12)、熊果酸(13)、委陵菜酸(14)。其中,化合物1-7为首次从南烛属植物分离得到,化合物8-11,14为首次从小果南烛植物中分离得到。     

Lyonin A, a new 9,10-Secograyanotoxin from Lyonia ovalifolia

Phytochemical studies on the branches and leaves of Lyonia ovalifolia yielded a new grayanane diterpenoid, lyonin A ( 1 ), together with two known compounds, secorhodomollolides A and D ( 2 and 3 , resp.). The structure of 1 was elucidated by combination of 1D‐ and 2D‐NMR, and MS analyses. Compound 1 turned out to be a new, highly O‐acylated grayanane diterpenoid, of which ring B has undergone an oxidative cleavage between C(9) and C(10), yielding a system differing from the previously reported grayanane type with a 5/7/6/5 ring system. Results of the cAMP regulation activity assay showed that compounds 2 and 3 at 50 μM induced a significantly decreased cAMP level in N1E‐115 neuroblastoma cells (p<0.001), indicating neuropharmacological potential.     

丹霞柿，广东柿属(柿科)一新组合及其一新异名

通过查阅模式标本后发现丹霞南烛(Lyonia danxiaensis R. H. MiaoW. Q. Liu)具有聚伞花序,花部为4数,雄蕊16枚且成对着生,花丝非膝曲状等特征与珍珠花属(Lyonia)不符,而与柿科(Ebenaceae)柿属(Diospyros)一致,因此提出一新组合:丹霞柿[Diospyros danxiaensis (R. H. MiaoW. Q. Liu) Y. H. TongN. H. Xia]。且经标本比对后发现,新近发表的彭华柿(Diospyros penghuae W. B. Liao, Q. FanW. Y. Zhao)与丹霞柿实为同种,在此也予以合并。     

Host‐associated pre‐mating reproductive isolation between host races of Acrocercops transecta: mating site preferences and effect of host presence on mating

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Host race formation in the leaf-mining moth Acrocercops transecta (Lepidoptera: Gracillariidae)

Genetic differentiation in ecological traits plays an important role in the reproductive isolation of phytophagous insects. The present study aims to elucidate the genetic changes involved during the process of host shifts, by combining analyses for (1) host adaptations, (2) pre‐ and postmating isolation, and (3) phylogeney among populations, using a leaf‐mining moth, Acrocercops transecta. This species is associated with Juglans ailanthifolia and Lyonia ovalifolia. Transplantation of the larvae demonstrated that the Juglans‐associated population completely failed to survive on Lyonia, whereas the Lyonia‐associated population survived on Juglans as well as on Lyonia. Females of respective host‐associated populations oviposited on their natal host plant only. An mtDNA‐based phylogeny clearly separated the Lyonia‐associated population from the Juglandaceae‐associated population, and indicated that the Lyonia‐associated population once evolved from the Juglandaceae‐associated population. These results indicate that the processes of host shifting from juglandaceous species to Lyonia involved genetic changes both in larval ability to use host plants and in host preference of females. The derived Lyonia‐associated population has retained the potential to assimilate the ancestral host, Juglandaceae. Mating between the two host‐associated populations was successful for both directions of crossing, and there were no significant differences in egg hatchability between hybrids and control crosses. No adults emerged when the F₁ hybrid larvae were maintained on Lyonia; however, on Juglans the F₁ hybrid larvae grew to adulthood as well as in the control, suggesting a lack of genomic incompatibilities between the two host‐associated populations. In conclusion, the results showed that the two host‐associated populations are host races that are partially reproductively isolated, and that the differences in performance and preference function as strong barriers against gene flow between the host races. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93 , 135–145.