Showing papers on "Excoecaria agallocha published in 2004"

Agallochaols a and b, two new diterpenes from the chinese mangrove Excoecaria agallocha L.

Abstract: Two new ent-isopimarane diterpenoids, agallochaols A (1) and B (2), were isolated from the dried stems and leaves of the mangrove Excoecaria agallochaL. Their structures were established on the basis of spectroscopic data and chemical evidence.

Diaspore traits and inter-tidal zonation of non-viviparous mangrove species

Abstract: Diaspore traits and germination of four non-viviparous mangrove species in Hong Kong, Lumnitzera racemosa (Jack.) Voigt., Heritiera littoralis (Drgand.) Ait., Excoecaria agallocha L. and Acanthus ilicifolius L., were investigated. L. racemosa fruits planted immediately after collection failed to germinate but those stored in wet condition for 35 or 50 d were successfully germinated. This suggested that L. racemosa had endogenous and morphological seed dormancy, with embryos continued to develop during the dormant period. Germination rates of L. racemosa decreased with increasing salinity and no germination was found at salinities over 25 ppt (ppt, parts per thausand). H. littoralis seeds were easily germinated if the fruit coat was artificially removed. Fruit dissection significantly shortened time for root initiation and leaf expansion. E. agallocha and A. ilicifolius seeds were also easy to germinate, initiating roots within 2 and 3 d, respectively. In terms of germination, A. ilicifolius had more tolerance to high salinity than L. racemosa. The four species exhibited three types of adaptation to unstable environments: (1) prolonged diaspore longevity as shown in L. racemosa and H. littoralis ; (2) shortened rooting time as in E. agallocha and A. ilicifolius ; and (3) produced sinking diaspores in L. racemosa. Diaspore buoyancy was one of the most important factors in determining inter-tidal zonation of non-viviparous mangrove species. Among the four species, L. racemosa was distributed in the most seaward zones because its diaspores were sinkers while diaspores of H. littoralis, E. agallocha and A. ilicifolius, more abundant at backshore locations, were floaters. Root initiation was also important in influencing the inter-tidal zonation of the three species whose diaspores were floaters. H. littoralis with the longest rooting time, as compared to E. agallocha and A. ilicifolius, was distributed in the most backshore zone. None of other factors including salinity of seawater, animal predation, diaspore size and seedling dimension could account for inter-tidal zonation of these species.

Ecological study on the mangrove communities in beilunhekou national nature reserve

Abstract: Ecological characteristics of habitat condition,flora,type,physiognomy,structure,species diversity and succession of mangrove communities in Beilunhekou National Nature Reserve,Guangxi,were systematically analyzed.14 species of mangrove plants,belonging to 11 families and 14genera,were found in the Reserve.Among them,11 species are true mangrove and 4 species are semi-mangrove.The true mangrove communities can be classified into 8 formations and 14 community types,and the main constructive species are Acrostichum aureum,Avicennia marina,Aegiceras corniculatum,Kandelia candel,Bruguiera gymnorrhiza,Excoecaria agallocha,Acanthus ilicifolius and Heritiera littoralis,respectively.The semi-mangrove communities can be classified into 2 formations and 2 community types,and the main constructive species are Hibiscus tiliaceus and Cerbera manghas,respectively.The Simpson index (D) of species diversity for the mangrove communities range from 1.09 to 5.34,Shannon-Weiner index (H) from 0.25 to 2.56,probability of interspecific encounter (PIE) from 0.08 to 0.82,and evenness (E) from 0.25 to 0.95.

Vegetation Analysis of Mangrove Forest of Krishna Wildlife Sanctuary , Andhra Pradesh , India

Abstract: Paper reports on a detailed analysis of a mangrove forest of Krishna Wildlife Sanctuary , Andhra Pradesh The study was conducted during July 2002 , and the vegetation was sampled through random sampling method This type of study is done for the first time in Indian Context The result shows that Avicennia officinalis , Rhizophora apiculata , Agiceras corniculatum , Bruguiera cylindrica , Ceriops decandra and Excoecaria agallocha are the common species with sufficient number of the individuals Good regeneration of all these species were also recorded Some areas viz , Nachugunta beat and Machlipatnam , support sparse vegetation composed of helophyte species ie Suaeda nudiflora , S monoicea , S maritima , Salcorina brachiata , Helotropium curassavicum and grasses Aeluropus lagopoides , Sporobolus verginicus , Spinifex littoreus and Zoysia mortella Few species of creeper Ipomoea pescarpae , herb Launea sarmentosa and hedges Cyperus arenarius and Fimbristylis polytrichoides have also been recorded In newly formed silt deposits in inter-tidal regions , the grass Porteresia coarcata found growing as pioneer species A pure stand of Prosopis juliflora spread over 6km area , where the seeds were brought by 1977 cyclone In Sorlagondi beat well grown trees of Salvadora persica were also noticed

Three Diterpenoids (Excoecarins V1—V3) and a Flavanone Glycoside from the Fresh Stem of Excoecaria agallocha.

Abstract: Three new diterpenoids, excoecarins V1-V3 (1-3) and a new flavanone glycoside (7) were isolated from the fresh stem of Excoecaria agallocha L. Their structures were elucidated as: 2alpha,3alpha,18-trihydroxy-3beta,20-epoxybeyer-15-ene (1), ent-2,3-secokaur-16-en-2,3-dioic acid (2), ent-3,4-seco-16alpha-hydroxyatis-4(19)-en-3-oic acid (3), and 3,5,7,3',5'-pentahydroxy-2R,3R-flavanonol 3-O-alpha-L-rhamnopyranoside (7) on the basis of spectroscopic data, chemical evidence, and/or X-ray analysis.