Molecular simulations of Taxawallin I inside classical taxol binding site of β-tubulin

A new taxoid Taxawallin I (1) along with two known taxoids (2-3) were isolated from methanolic bark extract of Taxus wallichiana Zucc. Structural characterization was confirmed by mass and NMR spectral techniques. Taxawallin I exhibited significant in-vitro anticancer activity against HepG2, A498, NCI-H226 and MDR 2780AD cancer lines. Tubulin binding assay was performed to assess its tubulin binding activity. Molecular docking analysis was performed to study the potential binding mode inside the taxol binding site of β-tubulin.     

Assessment of natural regeneration status and diversity of tree species in the biodiversity conservation areas of Northeastern Bangladesh

A study was conducted at two-biodiversity conservation areas of Northeastern Bangladesh (a part of Sylhet Forest Division) to assess the species composition, diversity and density of natural regeneration of tree species both indigenous and exotic species. Data were collected by stratified random quadrate method during January 2010 to July 2010. Totally 200 circular plots of 2 m×2 m in size had 5 different habitat types of plants namely; forest, roadside, homestead (surrounding forest dwellers house), fallow land and others (canals, streams and tea gardens side), which included a total of 55 regenerating species belonging to 28 families. Meliaceae is the dominant family and shows the highest family importance value (26.3), having six species, followed by Moraceae (24.24). Among the five habitat types, forest (43 species) possess the highest number of species, followed by roadside (23 species). Total 15 exotic species among 9 families and 40 indigenous species with 24 families were recorded. For exotic species, Tectona grandis possess the highest relative density (11.7%) and relative frequency (10.5%); Senna siamea had highest relative abundance (7.83%). In case of indigenous species, Chickrassia tabularis possess the highest relative density (4.23%) and relative frequency (4%); Dipterocarpus turbinatus had the highest relative abundance (3.92%). Tectona grandis (29.66) and Chickrassia tabularis (10.8) had the highest IVI for exotic and indigenous species respectively. Different diversity indices such as Shanon-Winner diversity index, species diversity index, species richness index, species evenness index, Simpson index and species dominance index, etc. were applied to quantify definite diversity. The regeneration of species associated with low levels of disturbance was in the exotic species. Study suggests that proper protection from human disturbances and scientific management of natural regeneration of two-study forests may lead a rich biodiversity site in the country.     

Phenolic glycosides from Dodecadenia grandiflora and their glucose-6-phosphatase inhibitory activity

Phytochemical investigation of Dodecadenia grandiflora leaves led to the isolation and identification of three phenolic glycosides, designated 1-[(4′-O-(E)-p-coumaroyl)-β-d-glucopyranosyl]-oxy-2-phenol (1), 1-[(6′-O-(E)-p-coumaroyl)-β-d-glucopyranosyl]-oxy-2-phenol (2) and 1-[O-β-d-glucopyranosyl(1→2)-β-d-glucopyranosyl]-oxy-2-phenol (3), along with nine known compounds. Compounds 1, 2, 5 and 9 exhibited significant glucose-6-phosphatase inhibitory activity (63.7, 66.9, 82.9 and 85.4%) with IC₅₀ values of 88.5, 81.0, 51 and 50 μM respectively. On the basis of biological results, a structure–activity relationship has been discussed.     

Leaf litter decomposition of dominant tree species of Namdapha National Park,Arunachal Pradesh,northeast India

Rates of weight loss and nutrient (N and P) release patterns were studied in the leaf litter of the dominant tree species (Ailanthus grandis, Altingia excelsa, Castanopsis indica, Duabanga sonneriatioides, Dysoxylum binectariferum, Mesua ferrea, Shorea assamica, Taluma hodgsonii, Terminalia myriocarpa and Vatica lancefolia) of a tropical wet evergreen forest of northeast India. Nitrogen and phosphorus mineralization rate and decay pattern varied significantly from species to species. In general, the decay pattern, characterized by using a composite polynomial regression equation, exhibited three distinct phases of decay during litter decomposition—an initial slow decay phase (0.063% weight loss day⁻¹), followed by a rapid decay phase (0.494% weight loss day⁻¹) and a final slow decay phase (0.136% weight loss day⁻¹). The initial chemical composition of the litter affected decomposition rates and patterns. Species like D. sonneriatoides, D. binectariferum, and T. hodgsonii with higher N and P content, lower carbon and lignin content, and lower C:N ratio and lignin:N ratio exhibited relatively faster decomposition rates than the other species, for example M. ferrea, C. indica and A. grandis. A slow decay rate was recorded for species such as M. ferrea, C. indica, and A. grandis. The initial N and P content of litter showed significant positive correlations with decay rates. Carbon and lignin content, lignin:N, and C:N showed significant negative correlations with decay rates. Soil total N and P, and rainfall, soil temperature, and soil moisture had positive correlations with decay rates. The rapid decomposition rates observed in comparison with other different forest litter decay rates confirm that tropical wet evergreen forest species are characterized by faster decomposition rates, indicating a faster rate of organic matter turnover and rapid nutrient cycling.     

孟加拉无机肥料对几种农林作物生物固氮和种苗生长的影响(英文)

比较了不同浓度无机肥料(尿素和重过磷酸钙)对四种农林作物(楹树、雨豆树、相思树和印度田菁)生物固氮和种苗生长的影响。种子萌发一个月后利用不同浓度肥料(尿素:40kg·hm-2,80kg·hm-2;重过磷酸钙:40kg·hm-2,80kg·hm-2;(尿素 重过磷酸钙)40kg·hm-2和(尿素 重过磷酸钙)80kg·hm-2)处理种苗。结果表明:中等浓度无机肥料促进了种苗的生长,但较高浓度无机肥料也不利于种苗的生长。当施加尿素时根瘤菌的数量大小明显受抑制,但随着增加磷肥(重过磷酸钙)根瘤菌的数量大小增加。本研究有助于农业人员利用无机肥料改善土壤提高农林作物的生物固氮和种苗生长。图2表6参33。     

Antibacterial activity of Artocarpus heterophyllus

The crude methanolic extracts of the stem and root barks, stem and root heart-wood, leaves, fruits and seeds of Artocarpus heterophyllus and their subsequent partitioning with petrol, dichloromethane, ethyl acetate and butanol gave fractions that exhibited a broad spectrum of antibacterial activity. The butanol fractions of the root bark and fruits were found to be the most active. None of the fractions were active against the fungi tested.     

1-(3-Hydroxy-4-methoxy-5-methylphenyl) ethanone, a new compound from the stem bark of Lamprothamnus zanguebaricus

The chloroform extract of the stem bark of Lamprothamnus zanguebaricus has yielded two ethanones; 1-(3-hydroxy-4-methoxy-5-methylphenyl)ethanone (I) (a new compound) and 1-(3-hydroxy-4-methoxyphenyl)ethanone (II). The structures of both compounds were established by spectroscopic methods.     

Vegetative propagation of Aesculus indica through stem cuttings treated with plant growth regulators

Cuttage propagation of Aesculus indica was tested by treatments with different concentrations of indole-3-acetic acid (IAA) @ 2000, 4000 (ppm), indolebutyric acid (IBA) @ 2000, 4000 (ppm) and naphthlcetic acid (NAA) @ 2000, 4000 (ppm) in dry formulation in the Forest Nursery, Faculty of Forestry, SKUAST-K, Shalimar. The cuttings treated with IBA @ 4000 ppm and IBA @ 2000 ppm had a sprouting rate of 75% and 50%, respectively, which was significantly higher than that of control and other treatments. The highest rooting rate (50%) was recorded in the cuttings with the application of IBA @ 4000 ppm. The cuttings treated with IBA @ 2000 ppm had 25% rooting rate. All other treatments along with control (talc powder) failed to induce rooting. It was concluded that IBA @ 4000 ppm was a better-applied concentration for vegetative propagation of A. indica under Kashmir conditions. Biography: Mumtaz Majeed (1980– ), male, post graduate in Faculty of Forestry, Sher-e-Kashmir University of Agricultural Science & Technology, Shalimar, Srinagar - 191 121, J&K, India.     

Projected benefit-cost analysis of agri-silvicultural system: vegetable crops intercropping with <Emphasis Type="Italic">Salix alba</Emphasis> (Willow)

An experiment upon an agri-silvicultural system involving Willow (Salix alba) tree, Kale (Brassica oleracea var. acephala) and Knol khol (Brassica oleracea var. caularapa) was laid in randomized block designed at farmers’ willow field at Shalimar near Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar India during 2005 and 2006. The main plot was divided into sub-spots with 8 m × 2 m in size each in which four two-year-old willow (Salix alba) trees were at a spacing of 2 m × 2 m in a sub-spot. The intercrops were maintained at recommended spacing and supplied with recommended doses of fertilizers. The benefit-cost ratio in willow plantation intercropped with vegetable crops of Kale and Knol Khol was analyzed and compared with the benefit-cost ratio of sole willow tree forestry. The results showed that every rupee invested in plantation of agri-silvicultural system generates benefit-cost ratio of 2.78 and 2.79 in case of Willow intercropping with Kale and Willow with Knol khol, respectively, while as for sole crop of willows benefit-cost ratio was calculated to be 2.66. These results provided circumstantial evidence in favour of adopting agroforestry involving willow instead of Sole tree forestry.