Overview of Research on Citral in Lauraceae Plants and Its Biological Activity

Citral is a monoterpene aldehyde,which is the main chemical component of essential oils from Litsea cubeba and Cymbopogon citratus,as well as one of the most important representatives of open-chain monoterpene compounds.The lemon flavor released by citral is very strong,and thus,it is widely used in essence,spices,manufacturing of various foods and beauty and other industries.It has antibacterial,anti-inflammatory,antioxidant,anti-tumor,insecticidal and other biological activity.This paper reviewed citral in Lauraceae plants and its biological activity,in order to provide reference for the development and utilization of citral in Lauraceae plants and its diversified applications.

An Uncertain Future for American Lauraceae: A Lethal Threat from Redbay Ambrosia Beetle and Laurel Wilt Disease (A Review)

Laurel wilt is a destructive vascular disease responsible for high mortality of American tree species in the family Lauraceae, particularly redbay (Persea borbonia) and swampbay (P. palustris), two dominant components of Coastal Plain forest communities in the southeastern United States. The disease syndrome emerged as a result of establishment of an exotic wood-boring beetle, Xyleborus glabratus, now known as the redbay ambrosia beetle. During gallery excavation, females of X. glabratus introduce a newly-described, obligatory fungal symbiont, Raffaelea lauricola. This fungus proliferates within the gallery and provides food for the beetles, but it has proven to be pathogenic to American lauraceous hosts, which have had no co-evolved history with R. lauricola. Presence of the foreign fungus elicits secretion of resins and formation of extensive parenchymal tyloses within xylem vessels. The extreme defensive response results in blockage of water transport, systemic wilt, and ultimately tree death. The beetle vector was first detected near Savannah, Georgia in 2002, and since has spread throughout the Southeast to become established in six states. The epidemic spread south through Florida more rapidly than predicted and currently threatens commercial production of avocado (Persea americana). Recent research indicates that California bay laurel (Umbellularia californica) can serve as a reproductive host for X. glabratus and is susceptible to laurel wilt disease. Thus, the US Pacific coastal forest ecosystems (and the California avocado industry) would be negatively impacted should the vector become established along the western coast. This review article summarizes our current understanding of the insect vector, the mycopathogen, and the susceptible host tree species. It also addresses elements of disease management and limitations with our current detection methods for redbay ambrosia beetle, which rely on manuka oil lures. Of the host-based attractants evaluated, cubeb oil shows the most promise as a potential new lure for X. glabratus.

The late Pliocene species with ternate venation of Lauraceae from Tuantian flora, Tengchong, Yunnan Province, China

A number of fossil leaves of the Lauraceae were collected from Tuantian flora of the late Pliocene strata in Yunnan, China. They have a whole leaf shape and well-preserved cuticles. In this paper, features of the architecture and epidermis of three species of the Lauraceae family with ternate venation are reported. Results of the comparison between the venation characteristics of Lauraceae fossils from four fossil floras in the world and those of extant Lauraceae in China suggest that the proportion of Lauraceae species with ternate venation is increasing. The proportion has risen from 10% in the Eocene to 12.5% in the late Pliocene in China, whereas the proportion in the modern era is 21%. Moreover, the proportion of Australian floras with ternate venation has rised from 8.3% to 10% between the Eocene and the Miocene. Because of the effect of the global drought during the Cenozoic era, we suggested that species with ternate venation in Lauraceae have become increasingly prevalent between the Eocene era and the present day in China. Data on Nerriga flora and Maarlake flora since the Eocene era in the Southern Hemisphere show the same trend. While features of the leaf architecture and epidermis of Lindera acuminatissima differ in details. They all have similar identification characteristics with regard to basal eucamptodromous venation, interior 2° present, minor 2° simple brochidodromous, anticlinal walls, no surface ornamentation, lip-like guard cells, outer stomatal ledge plain or dimness, and paracytic stomatal aperture. These differences are also present in extant species. Compared with Lindera tonkinensis, the nearest living relative(NLR) of L. acuminatissima shows that these differences are relevant to the growth, position, and development of leaves. Leaf-type classification statistics of L. acuminatissima indicate that when all fossil leaves are taken into consideration, A-type leaves account for 24%, B-type leaves make up 56%, and C-typy leaves account for 20%. Comparing the above result with that of NLRs, A-type leaves are generally immature spires and cannot be preserved easily, B-type leaves are regular mature leaves and fossilize more easil, and C-type leaves are usually old leaves occurring at the bottom, broken, ill and consumed by worms.

珍稀树种浙江楠植物物种鉴定

浙江楠（Phoebe chekiangensis C.B Shang）为樟科（Lauraceae）楠属（Phoebe）,是我国特有的珍稀树种,为我国著名植物分类学家向其柏教授于1974在研究天目山、龙塘山植物区系时发现的一个新种。因其木材坚韧致密,质地温润,纹理细密,富有光泽和香气,是楠木类中材质较佳的一种,也是优良的园林绿化树种。浙江楠树干通直,材质优良,用途广泛,木材可制作建筑、家具、雕刻等,由于历代对浙江楠的砍伐利用,成年植株直接受到破坏,野生大树数量急剧减少。

One New A-type Proanthocyanidin Trimer from Lindera aggregata(Sims) Kosterm.

One new A - type proanthocyanidin trimer, lindetannin trimer, was isolated from the stems of Lindera aggregata (Sims) Kosterm.. Its structure was elucidated by spectral and chemical methods.

Dendrochronology and climatic signals in the wood of Nectandra oppositifolia from a dense rain forest in southern Brazil

Nectandra is one of the most representative genera of Lauraceae in the subtropical Atlantic Forest of Brazil. The objective of this work was to study the dendrochronological potential of Nectandra oppositifolia Nees and Mart. from two sites in Santa Catarina State in southern Brazil. A tree-ring chronology of 34 trees was developed. The time span ranged from 1843 to 2013. The oldest and youngest trees were 171 and 47 years-old and the average length of the series was 103 years. Average diameter and annual increment were 20.64 cm and0.74 mm a-1; diameter and age were unrelated. The species has good dendrochronological potential with an intercorrelation of 0.61 between sites, indicating the existence of a synchronous pattern in the development of the trees. The climate response of the species could be seen by negative tree growth effects for previous hot and current rainy growth seasons.

中国樟科物种编目:问题和展望

樟科（Lauraceae）隶属于被子植物木兰亚纲（Magnoliidae）木兰超目（Magnolianae）樟目（Laurales）（Reveal＆Chase,2011）。该科的化石记录可追溯至白垩纪中期,现存50属2,500–3,000种,泛热带分布（李捷和李锡文,2004）,是被子植物分类中最困难的科之一（Paton et al.,2008）。

广西3科植物内生拟盘多毛孢多样性

为进一步了解植物内生拟盘多毛孢(Pestalotiopsis)的组成及变化规律,本研究对广西林科院植物园的壳斗科(10种)、樟科(7种)和棕榈科(5种)植物的内生真菌拟盘多毛孢多样性分四季进行了调查。经分离鉴定得拟盘多毛孢属真菌30种,其中从壳斗科分离到17种、樟科分离到19种、棕榈科分离到17种,优势种为小孢拟盘多毛孢(P.microspora)。从壳斗科的饭甑青冈(Cyclobalanopsis fleuryi),樟科的樟树(Cinnamomum camphora)和棕榈科的香桄榔(Arenga engleri)中分离得到的拟盘多毛孢种数分别为8、12和12种,这3种植物分别是3科中内生拟盘多毛孢定殖种类最多的代表物种;其中樟树内生拟盘多毛孢定殖率最高(6.67%)。除棕榈科植物软叶针葵(Phoenix roebelenii)外,内生拟盘多毛孢在植物枝条中的定殖率均高于叶片,而且这些植物枝条中内生拟盘多毛孢物种多样性更加丰富。春夏秋冬四季分离得到内生拟盘多毛孢分别为18、16、12和10种;定殖率分别为3.44%、1.53%、1.10%和1.75%;物种多样性指数分别为2.5006、2.2902、2.2475和1.9541。本研究表明拟盘多毛孢偏好在某些植物种类中定殖,并有明显的组织选择偏向性,且定殖率有季节差异性。

Eocene fossil Alseodaphne from Hainan Island of China and its paleoclimatic implications

Alseodaphne changchangensis sp. nov. (Lauraceae), with a perfectly preserved fossil leaf, was found in the Eocene Changchang Formation from the Changchang Basin of Hainan Island, China. This represents the earliest occurrence at the lowest latitude for the genus Alseodaphne, and offers important fossil evidence for further investigation of the origin and evolution of this genus and the paleo-climate of Hainan Island in the Eocene. Based on leaf morphology and cuticle characteristics, our fossil specimen is closest to the living species A. hainanensis Merrill, which is distributed mainly in tropical lowland rain forests, tropical montane rain forests, and subtropical montane evergreen broad-leafed forests on Hainan Island, and also found on the Wanshan Islands of Zhuhai of Guangdong Province and in northern parts of Vietnam. In the above areas, the climate factors are similar, i.e., the mean annual temperature is 20-22.6℃, the mean annual range of temperature 12-12.6℃ and the mean annual precipitation 1784-2500 mm. Based on the nearest living species analysis, we conclude that the climate of the Changchang Basin on Hainan Island during the Eocene was close to that of the distribution areas of the living A. hainanensis.

Ecological monophagy in Tasmanian Graphium macleayanum moggana with evolutionary reflections of ancient angiosperm hosts

Local host plant specialization in an insect herbivore may be caused by numerous factors, including host-specific natural enemy pressures or a local lack of suitable host-plant choices that are available elsewhere in its range. Such local specialization or ＂ecological monophagy＇, for whatever reason, may reflect reduced ability to behaviourally accept or physiologically utilize other allopatric hosts that are naturally used elsewhere by the species. We tested this feeding specialization hypothesis using the Tasmanian subspecies of Macleay＇s swallowtail butterfly, Graphium macleayanum moggana （Papilionidae）, which uses only a single host-plant species, Antherosperma moschatum （southern sassafras, of the Monlmiaceae）. Further north, this same butterfly species （G. m. macleayanum） uses at least 13 host-plant species from seven genera and four families （Lauraceae, Rutaceae, Winteraceae, and Monlmiaceae）. Our larval feeding assays with G. m. moggana from Tasmania showed that certain Magnoliaceae and Lauraceae could support some larval growth to pupation. However, such growth was slower and survival was lower than observed on their normal southern sassafras host （Monimiaceae）. We also found that toxicity of particular plant species varied tremendously within plant families （for both the Magnoliceae and the Monlmiaceae）.

Cinnamomum cebuense的化学成分(英文)

调查 Cinnamomum cebuense 的化学成分的目的，一棵地方性、极其危及的树仅仅在宿务岛发现了，菲律宾。混合物被硅石胶化层析孤立的方法。isolates 的结构被 NMR 光谱学阐明。结果 C 的 bark 的 dichloromethane (DCM ) 摘录。cebuense 负担得起一个新 monoterpene 天赋产品 1 并且新 sesquiterpene 2 与已知的混合物一起， 4-hydroxy-3-methoxycinnamaldehyde (3 ) ， 4-allyl-2-methoxyphenol (4 ) ， -terpineol (5 ) 和 humulene (6 ) 。C 的叶子的 DCM 摘录。cebuense 产出 6， -caryophyllene (7 ) ， squalene (8 ) ，和 -amyrin (9 ) 的混合物， -amyrin (10 ) 和 bauerenol (11 ) 。17 的结构被广泛的 1D 和 2D NMR 光谱学阐明，当 811 的结构被他们有那些的数据在文学报导了的 13C NMR 的比较识别时。结论 C 的 bark。cebuense 负担得起 monoterpenes， sesquiterpenes 和 phenolics，当叶子产出 sesquiterpenes 和 triterpenes 时。

Diverse sesquiterpenoids from Litsea lancilimba Merr.with potential neuroprotective effects against H_(2)O_(2)-induced SH-SY5Y cell injury

Five undescribed sesquiterpenoids(1–5),and nine known sesquiterpenoids(6–14)were obtained from the fruits of Litsea lancilimba Merr.by LC-MS/MS molecular networking strategies.Litsemene A(1)possessed a unique 8-member ring through unexpected cyclization of the methyl group on C-10 of guaiane.Their structures were elucidated by spectroscopic techniques including IR,UV,NMR,HR-ESI-MS,and their absolute configurations were assigned by ECD calculations.All isolated sesquiterpenoids were analyzed by bioinformatics and evaluated for their neuroprotective effects against H_(2)O_(2)-induced injury in human neuroblastoma SH-SY5Y cells.

PALEOBOTANY

20090382 Deng Shenghui (Research Institute of Petroleum Exploration and Development, Beijing 100083, China); Lu Yuanzheng Fossil Plants from Lower Cretaceous of the Jiuquan Basin, Gansu Province, Northwest China and Their Palaeoclimatic Implications (Acta Geologica Sinica, ISSN0001-5717, CN11-1951, 82(1), 2008, p.104-114, 2 plates, 59 refs.)