New gingerdione from the rhizomes of Zingiber officinale

A new gingerdione has been isolated from the rhizomes of Zingiber officinale and identified as 1-dehydrogingerdione (1).     

Floristic attributes of small cardamom (Elettaria cardamomum (L.) Maton) growing areas in the Western Ghats of peninsular India

A field study was conducted in the Western Ghats of peninsular India to test the following two hypotheses: (1) lower floristic diversity for the cardamom hill reserves (CHR —a traditional agroforestry system of the tropics) compared to undisturbed evergreen forests and (2) a truncated vegetation structure for shade trees in the cardamom areas. The experimental sites involved three CHRs and an evergreen forest site.The CHRs, regardless of their locations, were characterized by lower floristic diversity and density than the evergreen forest site. The undisturbed forest site at Ayyappancoil registered the highest floristic richness and diversity (Simpson's floristic diversity index, D=0.93), followed by the well-managed CHR site, suggesting that managerial interventions may have a strong bearing on the floristic diversity of CHRs. The current suite of species in the CHRs included both heliophilic as well as shade-tolerant components. However, dominant tree species, their density and relative abundance exhibited marked variations among the CHR sites, albeit about one-third of the species were common at all sites.Stand physiognomy was characterized by the dominance of a single layer of trees in the CHRs, while the wet evergreen forest exhibited a multilayered canopy structure. Some of the lower height classes were poorly represented in the cardamom areas, whereas the evergreen forests depicted an inverse J shaped height distribution pattern. Implicit in the truncated stand structure of the CHR is the poor regeneration status, due to systematic removal of the lower size classes.     

Litterfall,decomposition and nutrient release of <Emphasis Type="Italic">Shorea robusta</Emphasis> and <Emphasis Type="Italic">Tectona grandis</Emphasis> in a sub-tropical forest of West Bengal,Eastern India

We studied leaf litter fall, decomposition and nutrient release patterns of Shorea robusta and Tectona grandis by using a litter bag technique to better understand the release pattern of nutrients to soil from leaf litter. Annual litterfall varied from 13.40 ± 2.56 t ha^?1 a^?1 for S. robusta to 11.03 ± 3.72 t ha^?1 a^?1 for T. grandis and the decay constant (k) of decomposed leaf litter was distinctly higher for T. grandis (2.70 ± 0.50 a^?1) compared to S. robusta (2.41 ± 0.30 a^?1). Biomass loss was positively correlated with the initial litter C, WSC, C/N and ash content in S. robusta and N, P and K concentration for T. grandis. Biomass was negatively correlated with lignin and L/N ratio for S. robusta and L, WSC, L/N and C/N ratio for T. grandis (P < 0.01). Nutrient use efficiency (NUE) and nutrient accumulation index (NAI) of S. robusta was higher than for T. grandis. The retranslocation of bioelements from senescent leaves ranked as P > N > K. Annual N, P and K input to soil through litterfall differed significantly between the two species in the following order: N>K>P. S. robusta was superior in terms of K and P return and T. grandis was superior in terms of N return. The two tree species showed a similar patterns of nutrient release (K > P > N) during decomposition of their leaf litter. Nutrients of N, K and P were the primary limiting nutrients returned to soil through litterfall with important roles in soil fertility and forest productivity.     

A new phorbol diester from Aleurites moluccana

A new phorbol diester, 13-O-myristyl-20-O-acetyl-12-deoxyphorbol (1), has been isolated from the benzene extract of the heartwood of Aleurites moluccana. In addition, hentriacontane, 6,7-dimethoxycoumarin, 5,6,7-trimethoxycoumarin and beta-sitostenone are being reported for the first time from this species.     

Resistance of bamboo scrimber against white-rot and brown-rot fungi

ABSTRACT

Bamboo scrimber is one of the most emerging structural materials for future building applications and it possesses properties comparable to other natural wood-based engineered materials such as glulam, laminated veneer lumber and cross-laminated timber. The goal of this work was to study the decay resistance of bamboo scrimber against white-rot (Trametes versicolor) and brown-rot fungi (Serpula lacrymans). Bamboo scrimber samples were incubated in petri dishes with the wood-decaying fungi and the weight loss after 12 weeks was measured. The surface morphology of fungal-degraded bamboo scrimber was evaluated using optical microscopy. Based on the percentage weight loss, bamboo scrimber could be classified as highly resistant against bio-deterioration by white and brown-rot fungi.     

Antimicrobial activity of Ixora coccinea leaves

Ether and methanol extracts of Ixora coccinea dry leaves were tested for their antimicrobial activity. Ether fraction was found to be more active than the methanol fraction.     

Viability retention of seeds of shisham (Dalbergia sissoo Roxb.) on the trees after maturity

In 1991 and 1992 studies on Dalbergia sissoo Roxb. showed the availability of ample amount of viable seed from November to May. Viability of seeds collected from December to March was more than 90 per cent. There was a slight but significant decrease in germination from March to may. Again germination per cent was slightly and significantly decreased from May to July. Thereafter, seed availability and viability were got drastically reduced. Sufficient viable seed of Dalbergia sissoo Roxb. can be collected at any time from November to July.     

A new steroidal alkaloid from the seeds of Holarrhena antidysenterica

A new steroidal alkaloid, named antidysentericine, has been isolated from the seeds of Holarrhena antidysenterica and characterized as 3 beta-dimethylaminocon-5-enin-18-one (1).     

Accumulation of bioactive compounds during growth and development of mango ginger (Curcuma amada Roxb.) rhizomes

Accumulation of bioactive compounds and storage components during developmental stages of mango ginger ( Curcuma amada Roxb.) rhizome was investigated from 60 to 240 days, as a function of physiological maturity. Four distinct developmental phases were defined, namely, vegetative phase (up to 60 days from planting), initiation and development phase (60-150 days), maturation phase (150-180 days), and senescence phase (180 days). Difurocumenonol, a bioactive terpenoid compound and phenolics were identified as biomarkers, to determine the optimum physiological maturity to harvest mango ginger rhizome. Accumulation of phenolics was observed in newly initiated rhizomes (after 60 days from planting). The phenolic content was high in mango ginger pulp compared to its juice. Newly initiated rhizome contained no difurocumenonol, and it was observed after 120 days after planting. Peak accumulation of phenolics, difurocumenonol, and total protein were noticed in 180 day old rhizome. Accordingly, the abundance of these components on 180 days was set as an optimum maturity standard for harvest of mango ginger rhizome, compared with a conventional harvest period that ranges from 200 to 240 days.