Black pepper (Piper nigrum) is a spice vine crop which is used as a food preservative and as an essential component in traditional medicines. The aim of this study was to extract, isolate and characterize the structure of piperine. The fruits of black pepper were extracted in ethanol and compounds present identified by TLC under iodine vapour. A compound (A 2 ) having R f value 0.54 was isolated by column chromatography which may be responsible for the pungency of black pepper. After recrystallization of the isolate with benzene and chloroform mixture (7:1) gave pale yellow crystals of m.p. 128~129 o C (reported 130 o C). The IR, 1 H NMR and mass spectra of the pure crystalline compound (A 2 ) were recorded. The mass spectra of the compound (A 2 ) showed molecular ion peak M +· at 284.5 which was similar to that of piperine (mol. wt. 285).

An experiment was conducted at the Horticulture Farm, Bangladesh Agricultural University, Mymensingh to evaluate the  response of Biomeal, a commercial organic fertilizer in combination with inorganic fertilizers on growth, yield and quality named of carrot. The maximum gross yield (29.27 t ha-1) of carrot was obtained from T4 treatment [recommended dose of inorganic fertilizers (RDIF) + ½ recommended dose of Biomeal (RDB)], while the second lowest gross yield (18.73 t ha-1) was recorded in  alone RDB treatment. Carrot plants treated with RDIF showed the highest values for fresh weight of individual root (67.13 g), marketable yield (18.74 t ha-1), shoot length (47.87 cm), individual root diameter (10.91 mm) and nitrogen content in carrot (2.48%). Among the biochemical properties, the maximum amount of reducing sugar and total sugar (5.15 and 10.51%, respectively) were obtained from T7 treatment (RDIF + RDB). In context of carotene, the highest amount (4.92%) was found in T4 treatment (RDIF + ½ RDB). Considering major nutrients and biochemical properties of carrot, it can be inferred that Biomeal alone is not sufficient enough but it has positive influence when it is applied in combination with inorganic fertilizers. The study  also revealed that there was no significant contribution of Biomeal to increase organic carbon, N, P, S and Ca content in post  harvest soils. DOI: http://dx.doi.org/10.3329/jesnr.v5i1.11551 J. Environ. Sci. & Natural Resources, 5(1): 39 - 45, 2012