Pepper - chemistry, technology, and quality evaluation.
Pepper is the most important of the spices, with a long history. This article critically reviews our knowledge of the chemistry, processing, and quality evaluation of the product, with emphasis on the constituents contributing to the sensory properties of the spice for which it is valued in food. Other areas briefly summarized include its history, horticultural aspects, production and trade data, and physiological effects. Allied spices and aromatic members of the same family are also considered briefly.
Death of Cerebellar Granule Neurons Induced by Piperine Is Distinct from that Induced by Low Potassium Medium
We compared neurotoxicity of piperine and low K+on cultured cerebellar granule neurons. As considered from lactate dehydrogenase release and 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide reduction, both piperine and shifting from high K+(25 mM) to low K+(5.4 mM) were cytotoxic to cerebellar granule neurons. Protein synthesis inhibitors, cycloheximide and anisomycin, and an endonuclease inhibitor, aurintricarboxylic acid, were protective against low K+-induced neuronal death whereas they were ineffective against that induced by piperine. D-α-tocopherol, trolox, and a spin trap 3,3,5,5-tetramethyl-l-pyrroline-l-oxide were protective against piperine neurotoxicity whereas they had no effect on that induced by low K+. These results suggest that piperine and low K+may exert neurotoxic effects on cerebellar granule neurons through different mechanisms. Death of cerebellar granule neurons induced by piperine may be mediated by non-apoptotic mechanisms and may involve membrane lipid peroxidation and/or free radical generation.
New Sweet-Tasting C21-Pregnane Glycosides from Pericarps of Myriopteron extensum.
Ten novel C21 pregnane glycosides, extensumside C-L (1-10), were isolated as highly sweet-tasting substances from the edible pericarps of Myriopteron extensum (Wight) K. Schum by sensory-guided fractionation and purification. Their structures were determined through 1D and 2D NMR, such as HSQC, HMBC, 1H-1H COSY, HSQC-TOCSY, and ROESY, as well as other spectroscopic analysis combined with chemical evidence. These compounds shared the same aglycone, 3β,16α-dihydroxy-pregn-5-en-20-one, and contained the deoxysugar chain and the glucose chain which were linked to C-3 and C-16 of the aglycone, respectively. The sweetness potency was evaluated by a human sensory panel test and preliminary structure-taste relationship was discussed. The sweetness intensities of these compounds are between 50 and 400 times greater than that of sucrose. Furthermore, quantitation analyses of compounds 1, 3, 4, and 6 in different parts of M. extensum indicated that the concentrations of these sweet components in the pericarps are obviously higher than those in stems and roots.