Biologically important polyphenol (+)-catechin was isolated from catechu, the extract of the red heartwood of Acacia Catechu tree (Khoiyer tree). The isolation procedure was developed to get better yield (25%) and to reduce the isolation cost and time. The structure of the isolated (+)-catechin was confirmed with several spectral analyses and chemical studies. Keywords:  Acacia Catechu; (+)-catechin; Polyphenol. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1635

Laboratory experiments were carried out to investigate the efficacy of sugarcane bagasse-based lignin against four stored grain insect pests viz., Tribolium castaneum, Tribolium confusum, Sitophilus oryzae and Callosobruchus maculatus. Mortality was assessed after 24, 48 and 72 h of treatment and LD50 values were calculated at the respective time intervals. It was observed that T. castaneum is more susceptible to the lignin than the other test insects. Repellent activity of the product was conducted for T. castaneum and T. confusum. All the concentrations of the product were found to be repellent to both the insect species. Strong repellent activity was observed at concentrations of 471.57 and 628.76 µg.cm-2 to T. confusum showing the repellency of class V activity. Key words: Bagasse-based lignin, toxicity, repellency, Tribolium castaneum, T. confusum, Sitophilus oryzae, Callosobruchus maculatus Univ. j. zool. Rajshahi Univ. Vol.25 2006 p.27-30

An experiment was carried out to study the effect of phosphorus and zinc on yield, phosphorus and zinc content in rice as well as P distribution in post harvest soil, on a silty loam soil of Sonatola series (Non-calcareous Dark Grey Floodplain Soil) at Bangladesh Agricultural University Farm. There were 3 levels of P (0, 25 and 50 kg ha-I from TSP) and 4 levels of Zn (0,5,10 and 20kg Zn ha-1 from zinc sulphate) along with basal doses of 100 kg N ha-1 from urea, 40 kg K20 ha-1 from mediate of potash and 12 kg S ha-1 from gypsum. The single and interaction effect of P and Zn had significant positive effect on the grain and straw yield. The highest grain yield (5.97 t ha-l) and straw yield (11.50 t ha-1) were obtained from Zn10 P50 treatment. Phosphorus application significantly increased the P content in grain and straw but zinc content significantly decreased while effect of zinc significantly decreased the P content in grain and straw but increased the Zn content. The highest amount of P content in grain and straw were 0.35% and 0.140% respectively obtained from Zn0 P50 treatment whereas the zinc content in grain and straw were 32.8 ppm and 50.60 ppm respectively obtained from Zn20 P0 treatment. The availability of phosphorus gradually increased with the increasing levels of P and decreased with the increasing levels of Zn. The maximum water-soluble P (4.5mgkg-1) and labile P (1.8 mgkg-I) were obtained from Zn0 P50 treatment. The application of P and Zn gradually increased the Al-Fe-P, Mg/Ca-P and Total P with the increasing levels of P and Zn. The highest amount of Al/Fe-P, Mg/Ca­P and Total-P were obtained from Zn20 and P50 treatment. The combined application of P and Zn increased the grain and straw yield but decreased P and Zn content and availability of P to from Al/Fe-P and Mg/Ca-P as a result of Zn-P interaction in soil solution.

Studies were carried out on the lipid classes and fatty acid compositions of petuli seed oil. It was observed that petuli seed grown under the soil and climatic condition of Bangladesh contains about 22% pale yellow coloured oil. The total lipids were fractionated into three major lipid classes, neutral lipid glyco lipid and phospho lipid by silicic acid column chromatography. The neutral lipid was accounted to 92.5% of the total weight of the lipid applied. The oil was also fractionated into mono, di and triglyceride by silicic acid column chromatography.The triglyceride was counted for over 90% of the total weight of the oil. The fatty acid compositions of the oil were analyzed by Gas liquid Chromatography and found the major fatty acid α-elaeostearic acid 38.50%, oleic acid 34.35%, linoleic acid 26.15% and small amount of arachidic acid 1%.

When the raw and bleached jute were kept in air tight and normal conditions it was found that in normal condition the tensile strength of raw jute decreased with increase of times. But in air tight condition the decreasing rate of tensile strength of both kinds of jute was approximately similar.