Sathe, S.K., W.J. Wolf, K.H. Roux, S.S. Teuber, M. Venkatachalam, K.W.C. Sze-Tao, 2002. Biochemical characterization of amandin, the major storage protein in almond (Prunus dulcis L.). J Agric Food Chem.50(15):4333-41.
The almond major storage protein, amandin, was prepared by column chromatography (amandin-1), cryoprecipitation (amandin-2), and isoelectric precipitation (amandin-3) methods. Amandin is a legumin type protein characterized by a sedimentation value of 14S. Amandin is composed of two major types of polypeptides with estimated molecular weights of 42-46 and 20-22 kDa linked via disulfide bonds. Several additional minor polypeptides were also present in amandin. Amandin is a storage protein with an estimated molecular weight of 427,300 +/- 47,600 Da (n = 7) and a Stokes radius of 65.88 +/- 3.21 A (n = 7). Amandin is not a glycoprotein. Amandin-1, amandin-2, and amandin-3 are antigenically related and have similar biochemical properties. Amandin-3 is more negatively charged than either amandin-1 or amandin-2. Methionine is the first essential limiting amino acid in amandin followed by lysine and threonine.
Sang, S., G. Li, S. Tian, K. Lapsley, R.E. Stark, R.K. Pandey, R.T. Rosen, C.T. Ho, 2002. An unusual diterpene glycoside from the nuts of almond (Prunus amygdalus Batsch). Tetrahedron Letters. 44:1199-1202.
A new unusual diterpene glycoside, named amygdaloside, was isolated from almonds. Since this family of compounds is known to have anti-tumor and anti-inflammatory effects, further research is needed in this area.
Sang, S., K. Lapsley, W.S. Jeong, P.A. Lachance, R.T. Rosen, C.T. Ho, 2002. Antioxidative phenolic compounds isolated from almond skin (Prunus Amygdalus Batsch). J Agric Food Chem. 50:2459-63.
Nine phenolic compounds were isolated from the ethyl acetate and n-butanol fractions of almond (Prunus amygdalus) skins. On the basis of NMR data, MS data, and comparison with the literature, these compounds were identified as 3′-O-methylquercetin 3-O-beta-D-glucopyranoside (1); 3′-O-methylquercetin 3-O-beta-D-galactopyranoside (2); 3′-O-methylquercetin 3-O-alpha-L-rhamnopyranosyl-(1–>6)-beta-D-glucopyranoside (3); kaempferol 3-O-alpha-L-rhamnopyranosyl-(1–>6)-beta-D-glucopyranoside (4); naringenin 7-O-beta-D-glucopyranoside (5); catechin (6); protocatechuic acid (7); vanillic acid (8); and p-hydroxybenzoic acid (9). All of these compounds have been isolated from almond skins for the first time. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activities for compounds 1-9 were determined. Compounds 6 and 7 show very strong DPPH radical scavenging activity. Compounds 1-3, 5, 8, and 9 show strong activity, whereas compound 4 has very weak activity.
Sang, S., K. Lapsley, R.T. Rosen, C.T. Ho, 2002. New prenylated benzoic acid and other constituents from almond hulls (Prunus Amygdalus Batsch). J Agric Food Chem. 50:607-9.
One new prenylated benzoic acid derivative, 3-prenyl-4-O-beta-D-glucopyranosyloxy-4-hydroxylbenzoic acid, and three known constituents, catechin, protocatechuic acid, and ursolic acid, have been isolated from the hulls of almond (Prunus amygdalus). Complete assignments of the proton and carbon chemical shifts for the new prenylated benzoic acid derivative were accomplished on the basis of high-resolution 1D and 2D nuclear magnetic resonance data. All of these compounds except ursolic acid are being reported from almond hulls (P. amygdalus) for the first time.
Sang, S., K. Lapsley, X. Cheng, H.-Y. Fu, D.-E. Shieh, N. Bai, R.T. Rosen, R.E. Stark, C.-T. Ho, 2002. New type sesquiterpene lactone from almond hulls (Prunus Amygdalus Batch). Tetrahedron Letters. 43:2547-9.
An unusual sesquiterpene lactone, named amygdalactone, was isolated from almond hulls for the first time. This class of compounds is comprised of natural products with known anti-carcinogenic properties.
Sang, S., H. Kikuzaki, K. Lapsley, R.T. Rosen, N. Nakatani, C.-T. Ho, 2002. Sphingolipid and other constituents from almond nuts (Prunus Amygdalus Batsch). J Agric Food Chem. 50:4709-12.
One sphingolipid, 1-O-beta-D-glucopyranosyl-(2S,3R,4E,8Z)-2-[(2R)-2-hydroxyhexadecanoylamino]-4,8-octadecadiene-1,3-diol, and four other constituents, beta-sitosterol, daucosterol, uridine, and adenosine, have been isolated from the nuts of almond (Prunus amygdalus). Complete assignments of the proton and carbon chemical shifts for the sphingolipid were accomplished on the basis of high-resolution 1D and 2D NMR data. All of these compounds are being reported from almond nuts (P. amygdalus) for the first time.
Milbury, P., C.-Y. Chen, K,, H.-K. Kwak, J. Blumberg, 2002. Almond skins polyphenolics act synergistically with α-tocopherol to increase the resistance of low-density lipoproteins to oxidation. Free Radical Research. 36:1 Supp.: 78-80.
Researchers found in this study that the nutrients in almonds work together in synergy to produce a greater health-promoting effect than from individual nutrients consumed alone. Their emerging evidence indicates that the unique combination of almond skins keep LDL cholesterol from oxidizing, a mechanism associated with the formation of plaque in arteries of the heart. Even at very low levels, when the almond skins compounds combine with the vitamin E in the almonds and vitamin C from other foods, they act in synergy and play a co-defensive role against atherosclerosis–in a fashion where the sum of their actions is much greater than each par
Sathe, S.K., S.S. Teuber, T.M. Gradziel, K.H. Roux, 2001. Electrophoretic and immunological analyses of almond (Prunus dulcis L.) genotypes and hybrids. J Agric Food Chem. 49(4): 2043-52.
Aqueous extracts from sixty almond samples representing various genotypes and interspecies hybrids of almond, including almond-peach, were analyzed for protein and peptide content using electrophoresis, Western immunoblotting, and enzyme-linked immunosorbent assay (ELISA). Nondenaturing nondissociating polyacrylamide gel electrophoresis (NDND-PAGE) of the aqueous extracts indicated that a single major storage protein (almond major protein — AMP or amandin) dominated the total soluble protein composition. Denaturing SDS–PAGE analyses of the aqueous extracts revealed that the AMP was mainly composed of two sets of polypeptides with estimated molecular masses in the ranges of 38–41 kDa and 20–22 kDa, regardless of the source; however, distinct variations in the intensity and electrophoretic mobility of some bands were noted between samples. In addition to AMP, several minor polypeptides were also present in all the genotypes, and variations were seen in these as well. Regardless of the genotype, AMP was recognized in Western blots by rabbit polyclonal anti-AMP antibodies, mouse monoclonal anti-AMP antibodies (mAbs), and serum IgE from patients displaying strong serum anti-almond IgE reactivity. As with protein staining results, antibody reactivity also revealed common patterns but displayed some variation between samples. An anti-AMP inhibition ELISA was used to quantify and compare aqueous extracts for various samples. All samples (n = 60) reacted in this assay with a mean +/- standard deviation (sigma n) = 0.82 +/- 0.18 when compared to reference aqueous extract from Nonpareil designated as 1.0.
Ren, Y, K.W. Waldron, J.F. Pacy, P.R. Ellis, 2001. Chemical and histochemical characterization of cell wall polysaccharides in almond seeds in relation to lipid bioavailability. Biologically-active phytochemicals in food, (ed.) W. Pfannhauser, G.R. Fenwick & S. Khokhar, Royal Soc. of Chem., Cambridge, U.K. 448-452.
The research team reported that almond cell walls may prevent the body’s absorption of all the fat present in almonds. Normal chewing of almonds breaks down only some of the cell walls, leaving others intact. Thus, not all the fat was available for digestion.
Sze-Tao, K.W.C., S.K. Sathe, 2000. Functional properties and in vitro digestibility of almond (Prunus dulcis L.) protein isolate. Food Chem. 69:153-60.
Almond protein isolate (API) solutions were less viscous than those of soy protein isolate (SPI). The foaming capacity of API at pH 5.0 and 6.46 was comparable to that of SPI at pH 4.42 and 5.0. At pH 8.2, SPI had better foam capacity and stability compared to that of API. API had better oil absorption capacity than that of SPI [3.56 and 2.93 g/g dry weight basis (dwb), respectively]. Emulsion activity index (EAI) of API was significantly higher than that of SPI. API was easily hydrolyzed by pepsin in vitro.
