Capsaicinoids

Capsaicinoids Bromine vapor chamber unsaturated capsaicinoids are completely brominated. [48]... 

Capsaicin, also known as N-Vanillyl-8-methyl-6-(E)-noneamide, is the most pungent of the group of compounds called capsaicinoids It is a common ingredient in varieties of pepper such as habanero, Thai, tabasco, cayenne etc. One target with which capsaicin interacts is the capsaicin receptor, an ion channel belonging to the superfamily of TRP channels. Because of the structural relation to other TRP channels and because the vanilloid moiety is an essential component of capsaicin, the capsaicin receptor is also called TRPVI or vanilloid receptor (VR1). It is involved in heat and pain perception. 

Calcium cations 144,145, 311, 312 Calibration of the wavelength scale 21 Campesterol 213 Cannabinoids 288,291 Canrenone 411 Capsaicinoids 65 Carbadrine 76... 

Gnayfeed, M.H. et ah. Supercritical COj and subcritical propane extraction of pungent paprika and quantification of carotenoids, tocopherols, and capsaicinoids, J. Agric. Food Chem., 49, 2761, 2001. 

The first competitive TRPVl antagonist is capsazepine (3), a conforma-tionally constrained (9-demethyl thiourea analogue of capsaicin that emerged from a programme aimed at the optimization of the agonistic properties of capsaicinoids [66]. The second competitive antagonist to be... 

The pungent components of chili peppers belong to a class of substances known as capsaicinoids. The most pungent and most common substance in this family is capsaicin (Fig. 7.2.1) (N-[4-hydroxy-3-methoxyphenyl)methyl]-8-methyl-6-nonenamide). Other members of this family include dihydrocapsaicin (Fig. 7.2.2), nodihydrocapsaicin (dihydrocapsaicin with a (CH2)s linkage instead of (CH2)6),... 

Perjesi P, Kuzmaa M, Fodora K and Rozmera, Z. 2007. Application of crocin bleaching and deoxyribose degradation tests to assess antioxidant capacity of capsaicinoids and some selected flavonoids. Eur J Pharm Sci 32 39. 

Because of their complementary character, TLC and HPLC can be used simultaneously for the easier solution of complicated separation problems. Thus, the determination of cap-saicinoids in fruit of hot pepper Capsicum annuum L. by spectrophotometry, TLC and HPLC has been reported. Samples were homogenized with acetone followed by a homogenization with acetone-petroleum ether 1 1 v/v until the tissue was nearly white. The extract was filtered and the acetone was washed out by small amounts (0.01 ml) of water. The ether phase was dried with anhydrous NajSC and concentrated in vacuum at 30°C. The extract was separated on silica TLC plates using a petroleum ether-acetate-methanol (75 20 5) mobile phase. The capsaicinoids were scraped off the layer and further analysed by HPLC. The Rp values of carotenoids and capsaicinoids are listed in Table 2.2. It was stated that the method can be employed for the measurement of carotenoids in hot peppers [19]. 

THE Rf VALUES OF CAROTENOIDS AND CAPSAICINOIDS FORM CAPSICUM ANNUUM... 

I. Perucka and W. Oleszek, Extraction and determination of capsaicinoids in fruit of hot pepper Capsicum annuum L. by spectrophotometry and high-performance liquid chromatography. Food Chem. 71 (2000) 287-291. 

The primary chemicals of interest in chilies are capsaicinoids, namely capsaicin (0.02%) and dihydrocapsaicin (figure 8.11). Also found are flavonoids, carotenoids (capsanthin), steroid saponins (capsicidin), and ascorbic acid or vitamin C (0.2%). Capsaicin has a vanilloid chemical structure. Mechanisms of Action... 

Pigments capsorubin Flavors linalool, 3-carene, 2,3-butanedione Placenta. capsaicinoids... 

The nitrogenous compounds produced in pepper fruit, which cause a burning sensation, are called capsaicinoids. Capsaicinoids are purported to have antimicrobial effects for food preservation [46], and their most medically relevant use is as an... 

Capsaicinoids are very potent, humans can perceive >1 ppm yet capsaicinoids are odorless and tasteless. As birds are insensitive to capsaicinoids, the accumulation... 

Capsaicinoids Are Products of the Phenylpropanoid Pathway and the Branched Chain Fatty Acid Pathway... 

Capsaicinoids are synthesized by the condensation of vanillylamine with a short chain branched fatty acyl CoA. A schematic of this pathway is presented in Fig. 8.4. Evidence to support this pathway includes radiotracer studies, determination of enzyme activities, and the abundance of intermediates as a function of fruit development [51, 52, 57-63], Differential expression approaches have been used to isolate cDNA forms of biosynthetic genes [64-66], As this approach worked to corroborate several steps on the pathway, Mazourek et al. [67] used Arabidopsis sequences to design primers to clone the missing steps from a cDNA library. They have expanded the schema to include the biosynthesis of the key precursors phenylalanine and leucine, valine and isoleucine. Prior to this study it was not clear how the vanillin was produced, and thus the identification of candidate transcripts on the lignin pathway for the conversion of coumarate to feruloyl-CoA and the subsequent conversion to vanillin provide key tools to further test this proposed pathway. 

Validation of the role of femloyl-CoA in the synthesis of the vanillin precursor will be detection of the appropriate intermediates and/or enzyme activities in placental extracts that could account for the production of the predicted levels of capsaicinoids. The presence of low levels of monolignol intermediates could be explained by lignin biosynthesis. An alternate route from phenylalanine to vanillin has been considered by some investigators Orlova et al. [68] demonstrated the role of the benzenoid pathway in petunia flowers for the biosynthesis of phenylpropanoid/benzenoid volatiles. 

The intermediates for the branched chain fatty acid production have been detected in tissues [69], The saturated and desaturated forms of the branched chain acyl-ACP and acyl-CoA are in the same relative amounts as in the final capsaicinoid products, as demonstrated for two different cultivated species, habanero (C. chinense) and jalapeno (C. annuum). From these results the authors indicate that the desaturation step occurs prior to release from the FAS complex. 

The substrates for capsaicinoid synthase were first defined by Fujiwake et al. [70] to be vanillylamine and 8-methyl-6-nonenoyl CoA. The synthesis of dihydrocapsaicin and the other naturally occurring variants are achieved by condensation of vanillylamine with the respective branched chain acyl, for example, 8-methylnonanoyl-CoA. The gene for capsaicinoid synthase has been linked to an acyltransferase At3 or Punl) cloned by Kim et al. [66] and mapped to the C locus on chromosome 2 [71, 72], Direct biochemical confirmation of capsaicinoid synthase remains to be established. 

Capsaicinoids start to accumulate 20 days post anthesis and synthesis usually persists through Suit development [59, 62,73], The site of synthesis and accumulation of the capsaicinoids is the epidermal cells of the placenta in the fmit (Fig. 8.5) [60, 72, 73], Ultimately, the capsaicinoids are secreted extracellularly into receptacles between the cuticle layer and the epidermal layer of the placenta [74]. These receptacles of accumulated capsaicinoids are macroscopically visible as pale yellow to orange droplets or blisters on the placenta of many chile types (Fig. 8.5). 

Stored under continuous light, and placental extracts from non-pungent fruit could synthesize capsaicinoids if vanillylamine and isocapric acid are provided. Together, these results raise the possibility that the gene product at Pml is a regulatory gene or a structural gene upstream in either the phenylpropanoid pathway or the branched chain fatty acid pathway and not capsaicinoid synthase. 

Screening for no-heat mutants in Capsicum collections and populations is a common practice for pepper breeders, as capsaicinoid accumulation is unique to the members of genus. A second locus for control of capsaicinoid production exists in at least two other species, C. chinense and C. chacoense [82], and the mutation that revealed this second locus is called loss of vesicle (Lov). The blisters on the placental surface that fill with capsaicinoids are absent in these no-heat mutants. The gene product and map location of this mutation are not known. 

In addition to the simple Mendelian control of the ability to produce capsaicinoids at all controlled by Punl and Lov, there is also quantitative genetic inheritance, controlling the degree of heat [83, 84], and several QTLs associated with capsaicinoid accumulation have been reported [77,85]. A review of this approach for linking genetic markers with capsaicinoid biosynthetic genes is presented by Mazourek etal. [67]. 

Although most consumers appreciate the fieriness of chile, capsaicinoids are not perceived through odor or taste receptors but through the nociceptive pain receptors described earlier. The compounds in chile fruit that create the flavor and aroma are produced in the fruit wall. Buttery et al. [90] generated vacuum steam distilled oil from green bell pepper macerate, with well over 40 peaks on subsequent GC/MS analysis. Of these peaks, the major flavor compound associated with bell pepper aroma was 2-methoxy-3-isobutylpyrazine (Fig. 8.1). They also reported several monoterpenoids in abundance, limonene, trans- 3-ocimene, and linalool as well as other aliphatic aldehydes and ketones. The flavor composition of dried red bell pepper powder (sweet paprika) extracted with ether identified 44 key peaks by GC/MS [91]. In these dried samples the key compounds were P-ionone and several furanones. The post-harvest processing and the different fruit maturities as well as possible varietal differences are all causes for the different aromatic profiles. 

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