Abstract: Cassava (Manihot esculenta Crantz) tubers are known for their presence of carbohydrate content. But minor quantity of anti-nutrients is also present in the tuber. The present investigation is conducted to know about the minor anti-nutritional components present in the selected cassava tuber. The result of the work shows that among five selected varieties, Malayan contains high amount of tannin content which is 0.0575±0.001 mg/g when compared with other cassava varieties whereas Mulluvadi contains lower amount (0.0161±0.0025 mg/g ). In case of Sree Vijaya it is 0.0168±0.0024 mg/g, Sree Jaya which is 0.0187±0.0018 mg/g, and Swarna contains 0.0358±0.0025 mg/g. The phytate and total oxalate content is high in Swarna which is of 0.378% phytate and 0.023±0.002mg/gm total oxalate. The Mulluvadi tuber contains 0.243% of phytate and 0.015±0.02 mg/gm of total oxalate. The amount of phytate in Sree Vijaya, Sree Jaya and Malayan are 0.361 %, 0.324% and 0.287% respectively, where as the total oxalate content Sree Vijaya, Sree Jaya and Malayan were 0.017±0.003 mg/g, 0.019±0.004mg/g and 0.013±0.010mg/g respectively.
from 35.1 to 71.0 mg/100 g WM (Judprasong et al., 2006; Ruan et al., 2013; Tsi et al., 2005). The mean soluble oxalate content of the raw fruits of the three cultivars of bitter gourd analyzed in this study was 63.33 ± 5.42 mg/100 g WM. These levels in the raw fruits are not so important, as they are not eaten raw because they are bitter and not easy to chew. On a wet matter basis, the mean soluble oxalate of the three cultivars was 66.02 ± 3.75/100 g WM when the fruits were wok- fried the usual method for cooking these fruits. It was interesting to note that wok- frying marginally increased the total oxalate contents of wok- fried fruit (mean raw 85.90 ± 8.67 compared to mean cooked 88.06 ± 0.95 mg/100 g WM). This small increase in total oxalate con- tents of the wok- fried fruits can be explained by the loss of moisture during cooking (mean dry matter of the three raw fruits 5.53 ± 0.61% DM; cooked 16.45 ± 1.39 DM). In contrast, Judprasong et al. (2006) showed that boiling the fruit resulted in a 61.4% reduction in the solu- ble oxalate content of the fruit. The soluble oxalate would have been leached into the cooking water and discarded. Cooking the fruits in a wok with a small amount of oil would be a more common way to cook bitter gourd fruits in the regions where it is consumed. Overall, the oxalate contents of the wok- fried fruits of bitter gourds were not high when compared to other commonly consumed vegetables (Noonan & Savage, 1999; Savage et al., 2000). Also, bitter gourd fruits were not usually consumed as a separate vegetable in a meal. They were often added to a dish and mixed with other components. This would suggest that current patterns of use do not pose a health risk.
Commercially grown Thai vegetables such as Chinese convolvulus (Ipomoea reptans), Acacia pennata (Acacia pennata), and cultivated bamboo shoot (Bambusa spp.), contain more than 150 mg total oxalate/100g FW, while legume seeds such as soybeans (Glycine max) and pea- nuts (Arachis hypogaea) contain highest and moderate amounts of total oxalate, 204 ± 14 mg and 142 ± 35 mg/ 100g fresh weight (FW), respectively . The soluble oxalate levels of leafy Thai vegetables ranged from < 3 to 110 mg/100g FW . The total oxalate levels in some indigenous Thai fruits and vegetables such as Phyllan- thus embrica, Musa sapientum, Careya sphaerica and Eugenai grata were 2056.4 ± 27.5, 421.1 ± 2.9, 226.7 ± 2.7 and 151 ± 2.5 mg/100g FW, respectively, while the soluble oxalate content ranged from 51.3 to 1238.1 mg/ 100g FW . The distribution of oxalates in plants is also very variable. Some green leafy vegetables such as spinach, purple and green amaranth and colocasia con- tain very high oxalate levels .
Abstract: The total, soluble, and insoluble oxalate contents of fresh and wok-fried fat hen (Chenopodium album) leaves were extracted and measured using High pressure liquid chromatography. The total oxalate content of the raw leaves was 1112.4 mg/100 g dry matter (DM), and the levels were significantly reduced by boiling (682.8 mg/100 g DM) or cooking the leaves in a wok (883.6 mg/100 g DM). The percentages of soluble oxalate contents in the total oxalates of the raw and boiled leaves were similar (mean 75%), while the proportion of soluble oxalate content in the wok-fried leaves was reduced to 53.4% of the total, giving a significant increase in the insoluble oxalate content of the wok-fried leaves. The percentage of insoluble calcium in the total calcium was significantly reduced (p < 0.05) when the leaves were boiled, but the insoluble oxalate content significantly increased (67.2%) in the wok-fried leaves when compared to the content of the original raw leaves. Processing the cooked leaves into pesto or extracting the juice gave final products that contained significantly reduced total and soluble oxalate contents. The addition of calcium chloride to the juice caused a very small reduction in the soluble oxalate content in the juice.
Most parts of the plant contained high levels of oxalate. It is remarkable to note that the smaller leaves harvested from tap water irrigated plants contained 10.7% total oxalate on a DM basis, while the leaves harvested from plants harvested from plants irrigated with fertilizer contained 5.2% total oxalate on a DM basis. In contrast, the water-irrigated large leaves contained 8.0% total oxalate on a DM basis and the fertilizer-watered large leaves contained 4.7% on a DM basis. The small and large miner’s lettuce leaves, irri- gated with fertilizer resulted in approximately 47% reduction in the total oxalate on a DM basis when compared to the leaves harvested from the water-irrigated plants. Overall the irrigation of the plants with nitrate fertilizer significantly reduced the oxa- late contents of all parts of the plants which confirm the observation on the response of Hibiscus sabdariffa .
The soluble oxalate content of foods can also be reduced by the addition of foods containing high levels of soluble calcium. Examples include adding sour cream to baked yams, adding milk to cooked taro leaves and serving cooked spinach with milk, cream or cottage cheese and consuming ice cream with rhubarb (Savage, 2002). Albihn and Savage (2001) showed that 100 g baked oca (containing 403.4 mg total oxalate) consumed with 100 g of sour cream effectively reduced the urinary oxalate to zero which strongly suggests that no soluble oxalate was absorbed from the baked oca. Oscarsson and Savage (2007) showed that baking taro leaves with milk reduced the soluble oxalate three-fold compared to the raw leaves (72.4 to 23.7%). More recent studies carried out by Simpson, Savage, Sherlock and Vanhanen, (2009) confirmed that addition of standard milk, low fat milk and cream to boiled silver beet leaves were each very effective at reducing the soluble oxalate content of the final mix. It was interesting to note that low fat milk (0.5% fat) had the same levels of calcium as the other two milk sources but was more effective at reducing the total soluble oxalate content. In contrast, there appeared to be little or no correlation between fat addition in a diet and oxalate absorption in the experiments carried out by Brogen and Savage (2003) or Mårtensson and Savage (2008).
Abstract: Three bulk samples of two different cultivars of kiwifruit, green (Actinidia deliciosa L.) and golden (Actinidia chinensis L.) were bought ripe, ready to eat from a local market. The aim of the study was to determine the oxalate composition of each of the three fractions of kiwifruit, namely skin, pulp and seeds. The pulp consisted of 90.4% of the edible portion of the two cultivars while the skin and seeds made up a mean of 8.0% and 1.6% respectively. Total oxalate was extracted with 2.0 M HCL at 21 °C for 15 min and soluble oxalates extracted at 21 °C in water for 15 min from each fraction. The total and soluble oxalate compositions of each fraction were determined using ion exchange HPLC chromatography. The pulp of golden kiwifruit contained lower amounts of total oxalates (15.7 vs. 19.3 mg/100 g FW) and higher amounts of soluble oxalates (8.5 vs. 7.6 mg/100 g FW) when compared to the green cultivar. The skin of the green cultivar contained lower levels of insoluble oxalates (36.9 vs. 43.6 mg/100 g FW), while the seeds of the green cultivar contained higher levels of insoluble oxalates 106.7 vs. 84.7 mg/100 g FW.
Parsley is native to the Mediterranean region and has since become naturalised in most areas worldwide. There are two main types of leaf parsley: curly leaf (Petroselinum crispum) and flat leaf (P. crispum var. neapolita- num). The unique taste of parsley means that it is commonly used in cooking as a garnish and as a tasty herb in many dishes. In European cooking, curly leaf parsley is often sprinkled as a garnish on many fish, potato and chicken dishes. It is also included in roux-based sauces on, or with, fish or gammon. The Italian dish, salsa verde, contains parsley as a main ingredient, while in French cuisine, large amounts of parsley are mixed with garlic to make persillade. Curly leaf parsley is used as a minor addition in many dishes but some chefs mention that the flat leaf cultivar has a more intense flavour. Parsley is reported to be a good source of antioxidants, fla- vonoids, folic acid, vitamins A, K and C and carotenoids, but their possible anti-nutritive constituents have not yet been addressed. Parsley may be a source of potentially harmful compounds such as oxalates. An early report on the oxalate content of a range of vegetables  indicated that moss curled parsley contained 166.0 mg/100 g fresh material, while a later report  indicated that parsley grown in the USA contained 170 mg total ox- alates/100 g wet matter (WM). A review of a wide range of vegetables  reported that parsley contained be- tween 140 - 200 mg of total oxalates/100 g WM and placed it in Group 3 (where the ratio of oxalate to calcium is <1) because it was reported to contain high levels of calcium (180 - 290 mg/100 g WM). These results sug- gested that much of the oxalate found in parsley may be bound to calcium, making both of them unavailable for absorption. More recently , parsley grown in Egypt was shown to contain 156 ± 1.02 mg total oxalate/100 g WM and 33.0 ± 0.76 mg soluble oxalate/100 g WM, when measured by an enzyme kit method that used oxalate oxidase. These results were comparable to the values measured using the AOAC method  (150 ± 1.30 mg to- tal oxalates/100 g WM and 30.0 ± 0.70 mg soluble oxalates/100 g WM) on the same samples. In the AOAC method , the extracted oxalates were measured using titration with KMnO 4 . In contrast, parsley grown in Italy
tors affecting the prevalence of kidney stones in Iran (12-14). In 2016, the prevalence of calcium oxalate stones reported as 61.25% (12-16). Researchers claim that there is a direct relationship between the oxa- late calcium stone formation and use of oxalate-rich foods (spinach, almond, cashews, grits, beets, cocoa powder, okra); also use of many common antibiotics that reduce the oxalate-degrading bacteria has been reported (16, 17). The oxalate degrading bacteria live in the digestive tract and cause the oxalate to be balanced (18-20). Laboratory studies indicate that most mammals are not able to decompose oxalate and, therefore, excrete it through urine, which ulti- mately causes calcium oxalate deposition and kidney stone formation (19, 21). Recently, various research- es have demonstrated the use of oxalate-degrading bacteria in various in vitro and in vivo experiments for the treatment of hyperoxaluria (5, 15, 24). How- ever, extensive research suggests that probiotic bac- teria have high oxalate degradation potential. Oxa- late-degrading bacteria convert oxalate to formate and carbon dioxide by certain enzymatic pathways (22, 23).
glutaraldehyde (2.5% in 0.1M sodium phosphate buffer, pH 7.0) was added to the test tube. The strip containing afÞ xed glass beads was allowed to stand for 2 h at room temperature with constant shaking. The strip was taken off glutaraldehyde solution and dipped repeatedly in to distilled water until the pH of the washing was 7.0, to ensure the complete removal of free glutaraldehyde. The beads were washed Þ nally in 0.1 M sodium phosphate buffer (pH 7.0). The end of plastic strip containing glutaraldehyde activated glass beads was dipped in to oxalate oxidase solution (3 ml) in a 15 ml test tube and allowed to stand at 4° for 48 h with occasional shaking. After the immobilization, the strip was taken off and the remaining enzyme solution was tested for activity and protein. The strip was dipped in to distilled water 6 times to remove the unbound enzyme and tested for enzyme activity.
removed from the atmosphere of the jar during the initial stages of the microbial fermentation of kimchi. There are two reasons for the reduction of oxalate contents during the lactic acid fermentation in the kimchi: (1) as the pH was reduced, the form of oxalate would change from insoluble oxalate bound to calcium ions to soluble oxalate ; and (2) this, then, will increase the soluble oxalate content of the liquid fraction of the kimchi mix and the increased soluble oxalate content could then be used as an energy source by the oxalotrophic bacteria present in the kimchi fermentation reducing both the total and the soluble oxalate contents of the final product in the process. This supports the observations made in an earlier study where Lactobacillii plantarum, was reported to be found in the kimchi in large numbers [7–9] and were found to degrade oxalate in other studies .
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molecule exists in the cationic form and the oxalic acid molecule in the mono-ionized state. The alaninium and semi- oxalate ions form alternate columns leading to a layered arrangement parallel to the ac plane and each such layer is interconnected to the other through NÐH O hydrogen bonds. The overall aggregation pattern is distinctly different from that observed in the glycine±oxalic acid complex.
calcifications. This paper reports the presence of Gla in the EDTA-soluble, nondialyzable proteins of calcium-containing renal calculi including calcium oxalate, hydroxyapatite, and mixed stores of apatite and struvite (MgNH4PO4). Calculi composed of pure struvite and those composed of only uric acid or cystine do not contain Gla. From calcium oxalate and hydroxyapatite stontes, a protein of about 17,000 daltons was obtained which contained about 40 residues of Gla per 1,000 amino acids. The amino acid composition of this protein had no apparent relationship to the Gla-containing bone protein or to the similarly-sized F1 fragment of prothrombin which contains about 64 residues of Gla per 1,000 amino acid residues. The Gla-rich protein in calcium-containing renal stones thus may be a different Gla-containing protein. These data as well as other studies demonstrating the presence of Gla in pathologically calcified tissues not normally containing Gla suggest that the Gla- containing proteins may be of considerable pathophysiological significance.
due to hepatic enzyme deficiency result in chronic hyperoxaluria, promoting end-stage renal disease in children and young adults. Ethylene glycol poisoning also results in hyperoxaluria, promoting acute renal failure and frequently death. Stiripentol is an antiepileptic drug used to treat children affected by Dravet syndrome. It has been shown to inhibit neuronal lactate dehydrogenase 5 enzyme. As this isoenzyme is also the last step of hepatic oxalate production, we hypothesized that stiripentol would potentially reduce hepatic oxalate production and urine oxalate excretion. In vitro, stiripentol decreased the synthesis of oxalate by hepatocytes in a dose-dependent manner. In vivo, oral administration of stiripentol significantly reduced urine oxalate excretion in rats. Stiripentol protected the kidneys against calcium oxalate crystal deposits in acute ethylene glycol intoxication and chronic calcium oxalate nephropathy models. In both models, stiripentol significantly improved renal function. Patients affected by Dravet syndrome and treated with stiripentol had a lower urine oxalate excretion than control patients. A young girl affected by severe type I hyperoxaluria received stiripentol for several weeks, and urine oxalate excretion decreased by two-thirds. Stiripentol is a promising potential therapy against genetic hyperoxaluria and ethylene glycol poisoning.
toxins while conserving extracellular fluid volume. Human urine and blood are supersaturated with respect to cal- cium oxalate (1) and calcium hydro- gen phosphate (13), respectively, yet solid phases rarely form because we produce inhibitors to initial nucle- ation and subsequent aggregation (12). In rats, stone formation occurs when the magnitude of the supersatu- ration overcomes this potent inhibi- tion (14). The current study should point us in the direction of investigat- ing the relationship between supersat- uration and inhibitor proteins not only in the urine but in the intersti- tium as well.
Kidney stones are hard, and solid particles and occur due to several factors like excess amount of stone forming constituents (Calcium oxalate, calcium phosphate, uric acid struvite, and cysteine), imbalance between promotors (eg. Sodium urateset) and inhibitors like citrate, glycosaminoglycans, etc. There are different sizes of stones. In many cases, the stone are very small and can pass out of the body without any problem. However, if a stone blocks the flow of urine, excruciating pain occurs and prompt medicinal treatment is needed. 
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molecule exists in the protonated cationic form and the oxalic acid molecule in the mono-ionized state. The alanine mol- ecules dimerize across inversion centres through head-to-tail NÐH O hydrogen bonds. The semi-oxalate ions aggregate into hydrogen-bonded strings along the shortest cell axis. The crystal structure is also characterized by the presence of a CÐ H O hydrogen bond and a short C O contact between amino acids.
0.563 (2)Å,4.5 (2)° and 172 (3)°, respectively; (Cremer & Pople, 1975). Bond lengths are in normal ranges (Allen et al., 1987). The dihedral angles between the mean planes of the cyclopropyl ring and the 10-membered quinoline ring are 50.6 (5)° (A) and 62.2 (5)° (B), respectively. In the cations, a single O—H···O intramolecular hydrogen bond is observed. In the crystal, the oxalate anions interact with the cations through N—H···O intermolecular hydrogen bonds and weak C —H···O intermolecular interactions forming R 2 2 (8) graph set ring motifs (Fig. 2). A weak C—H···F intermolecular
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Fig. 1 shows the molecular structure with the atom-numbering scheme. The asymmetric unit contains two leucinium cations and two semi-oxalate anions; the former have protonated amino groups and uncharged carboxylic acid groups, the latter each have a neutral carboxylic acid group and a negatively charged carboxylate group. The two cations exibit significant differences in conformation, as do the two anions (Table 1; corresponding angles are listed side-by-side). The semi-oxalate ions are related to each other through a psuedo-inversion centre. Interestingly, the two leucinium cations are also related by a psuedo-inversion centre, ignoring the side chain C atoms. A feature common to the crystal structures of glycinium oxalate, L-alaninium oxalate and (I) is that the shortest cell dimensions are similar, viz. 5.650 (2), 5.630 (1) and 5.674 (3) Å, respectively.
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showed total loss of hepatic architecture with centrilobular hepatic necrosis, fatty changes, vacuolization and congestion of sinusoids, kupffer cell hyperplasia 20 crowding of central vein and apoptosis. Treatment with petroleum extract of D. kaki at a dose of 200 mg/kg b.w. showed moderate to weak activity in protecting the liver cells from CCl 4 -injury. Among the plant extract, treatment