it has now been determined that fatty acids having seven carbons ( c 7 ) or their triglycerides do not require the usual enzymes needed for transporting long - chain fatty acids into the mitochondrion for energy production , i . e ., carnitine / acylcarnitine translocase , carnitine palmitoyltransferase (“ cpt ”) i and cpt ii . thus , triglycerides composed of seven - carbon fatty acids are useful as a nutritional supplement to overcome fatty acid metabolism deficiencies that require such enzymes . nutritional supplements or pharmaceutical preparations comprising seven - carbon fatty acids are useful in treatment of inherited metabolic disorders as well as acquired metabolic derangements . a preferred seven - carbon fatty acid is n - heptanoic acid . n - heptanoic acid is a saturated straight chain seven - carbon fatty acid with the following structure : triheptanoin is a triglyceride made by the esterification of three n - heptanoic acid molecules and glycerol . in regard to therapy , the terms heptanoic acid , heptanoate , and triheptanoin may be used interchangeably in the following description . also , it will be understood by those skilled in the art that heptanoic acid , heptanoate , and triheptanoin are used throughout the following description as an exemplary seven - carbon fatty acid source of the invention and is intended to be illustrative of the invention , but is not to be construed to limit the scope of the invention in any way . substituted , unsaturated , or branched heptanoate , as well as other modified seven - carbon fatty acids can be used without departing from the scope of the invention . triheptanoin is first broken down into three molecules of heptanoic acid and glycerol . as illustrated in fig2 the heptanoic acid is then broken down through normal β - oxidative procedures to n - valeryl - coa ( c 5 ) and acetyl - coa ( c 2 ) in the first cycle . in the second cycle , the n - valeryl - coa is then broken down to propionyl - coa ( c 3 ) and acetyl - coa ( c 2 ), both of which are important precursors as fuel for the kreb &# 39 ; s cycle and energy production . triheptanoin , therefore , is useful as an efficient source of fuel for energy production . additionally , propionyl - coa is a direct precursor for glucose production . consequently , triheptanoin is useful as a dietary supplement for patients susceptible to hypoglycemia , especially for premature infants and the elderly . triheptanoin can also be utilized as a growth rate stimulant for premature infants , allowing for shorter hospitalizations and thereby reducing medical costs for these infants . further , since fatty acids are the major fuel for heart tissue and because it has the property of being gluconeogenic , triheptanoin can be used in direct fueling of heart tissue in adults recuperating from cardiac or other high - risk surgery . heptanoic acid is found in various fusel oils in appreciable amounts and can be extracted by any means known in the art . it can also be synthesized by oxidation of heptaldehyde with potassium permanganate in dilute sulfuric acid . ( ruhoff , org syn coll . vol ii , 315 ( 1943 )). heptanoic acid is also commercially available through sigma chemical co . ( st . louis , mo .). triheptanoin can be obtained by the esterification of heptanoic acid and glycerol by any means known in the art . triheptanoin is also commercially available through condea chemie gmbh ( witten , germany ) as special oil 107 . unsaturated heptanoates can also be utilized as a nutritional supplement to overcome fatty acid metabolism deficiencies . in addition , substituted , unsaturated , and / or branched seven - carbon fatty acids which readily enter the mitochondrion without special transport enzymes can be utilized in the present invention . for example , 4 - methylhexanoate , 4 - methylhexenoate , and 3 - hydroxy - 4 - methylhexanoate are broken down by normal β - oxidation to 2 - methylbutyric acid with final degradation accomplished via the isoleucine pathway . likewise , 5 - methylhexanoate , 5 - methylhexenoate , and 3 - hydroxy - 5 - methylhexanoate are broken down by normal β - oxidation to isovaleric acid with final degradation accomplished via the leucine pathway . the seven - carbon triglycerides of the present invention can be administered orally , parenterally , or intraperitoneally . preferably , it can be administered via ingestion of a food substance containing a seven - carbon fatty acid source such as triheptanoin at a concentration effective to achieve therapeutic levels . alternatively , it can be administered as a capsule or entrapped in liposomes , in solution or suspension , alone or in combination with other nutrients , additional sweetening and / or flavoring agents . capsules and tablets can be coated with sugar , shellac and other enteric agents as is known . the method of administration is determined by the age of the patient and degree of fatty acid metabolism deficiency . for the treatment of infants with fatty acid metabolism defects , especially translocase deficiency , triheptanoin is preferably added as a nutritional supplement to a dietary infant formula comprising low fat and / or reduced long - chain fatty acids . exemplary commercially available infant formulas for use with triheptanoin include tolerex ( novartis nutritionals , minneapolis , minn . ), vivonex ( ross laboratories , columbus , ohio ), and portagen and pregestamil ( mead johnson ( evansville , ind .). triheptanoin is added to the formula at a concentration effective for achieving therapeutic results . for children and adult patients requiring a nutritional supplement , e . g ., surgery or oncology patients undergoing chemotherapy , triheptanoin is preferably supplied as a nutritional drink or as part of a total parenteral nutrient administration . for patients suffering from a complete breakdown of the fatty acid metabolic pathway due to an inborn error of metabolism , triheptanoin is utilized at a concentration which provides approximately 15 % to 40 %, preferably 20 % to 35 %, and most preferably approximately 25 % of the total calories per 24 hours . for patients in which the fatty acid metabolic pathway is functional at a reduced efficiency ( e . g ., premature infant , elderly , cardiac patient ), triheptanoin is utilized at a concentration which provides approximately 15 % to 40 %, preferably 20 % to 35 %, and most preferably approximately 25 % of the total calories per 24 hours . ince propionyl - coa is a metabolic by - product of triheptanoin oxidation , increased blood levels of propionic acid can result . moreover , propionyl - coa can enter into other enzymatic reactions which produce toxic compounds affecting the kreb &# 39 ; s cycle and the urea cycle . therefore , the administration of a seven - carbon fatty acid such as n - heptanoic acid and / or triheptanoin supplement , especially in patients exhibiting a build - up of serum propionic acid , may require the administration of a carnitine supplement and / or a biotin and vitamin b12 combination . in the presence of excess l - carnitine and the mitochondrial enzyme camitine acetyltransferase , propionyl - coa is converted to propionylcarnitine , a non - toxic substance which is excreted in the urine . biotin is a vitamin cofactor required for the enzyme propionyl - coa carboxylase which catalyzes the conversion of propionyl - coa to methylmalonyl - coa . cyanocobalamin is a form of vitamin b12 which acts as a cofactor for the enzyme methylmalonyl - coa mutase which catalyzes the conversion of methylmalonyl - coa to succinyl - coa . succinyl - coa is readily pulled into the kreb &# 39 ; s cycle . therefore , excess propionyl - coa in the patient &# 39 ; s blood is removed by conversion to succinyl - coa . the addition of n - heptanoic acid to cultured cells ( fibroblasts ) taken from patients with a lethal form of translocase deficiency indicated successful oxidation . because a sibling had died at the age of four days from severe translocase deficiency , amniocytes obtained from a fetus were examined for competency in fatty acid metabolism . the tests revealed that the fetus also had severe translocase deficiency . fibroblasts taken from the deceased sibling and amniocytes taken from the fetus were both evaluated for fatty acid metabolism of n - heptanoic acid ( c 7 ) using a tandem mass spectrometry assay previously reported . ( yang , et al . 1998 . “ identification of four novel mutations in patients with carnitine palmitoyltransferase ii ( cpt ii ) deficiency ,” mol genet metab 64 : 229 - 236 ). the mass spectrometry results are presented for palmitate in fig3 a and triheptanoin in fig3 b for the fibroblasts taken from the deceased sibling , and for palmitate in fig4 a and triheptanoin in fig4 b for the amniocytes taken from the fetus . results of the study showed that n - heptanoic acid ( fig3 b and 4b ) was independent of carnitine / acylcarnitine translocase and readily oxidized to propionyl - coa despite the translocase deficiency in both cell lines . based on the successful metabolism of n - heptanoic acid by the two cell lines having severe translocase deficiency , the tandem mass spectrometry assay was performed on fibroblast cell lines taken from normal patients and from patients affected by the following inherited defects of fat oxidation as proven by direct enzyme assay in other collaborating laboratories : carnitine palmitoyltransferase i ( cpt i ); severe carnitine / acyl carnitine translocase ( translocase ); carnitine palmitoyltransferase ii ( cpt ii ); the “ cardiac ” form of very - long - chain acyl - coa dehydrogenase ( vlcad - c ); the “ hypoglycemic ” form of very - long - chain acyl - coa dehydrogenase ( vlcad - h ); the mitochondrial trifunctional protein ( trifunctional ); long - chain l - 3 - hydroxy - acyl - coa dehydrogenase ( lchad ); medium - chain acyl - coa dehydrogenase ( mcad ); short - chain acyl - coa dehydrogenase ( scad ); electron transfer flavoprotein qo dehydrogenase - mild ( etf - dh mild ); and electron transfer flavoprotein qo dehydrogenase - severe ( etf - dh severe ). each cell line was incubated separately with 7 - 2 h 3 - heptanoate ( d3 - c7 ), 8 - 2 h 3 - octanoate ( d3 - c8 ), 9 - 2 h 3 - nonanoate ( d3 - c9 ), and 16 - 2 h 3 - palmitate ( d3 - c16 ). the results are given as tandem mass spectrometry in fig5 a - l for d3 - c7 ; fig6 a - l for d3 - c8 ; fig7 a - l for d3 - c9 ; and fig8 a - l for d3 - c16 . the normal cell line and eleven abnormal cell lines were analyzed in groups of three . for quantitative purposes , labeled internal standards were included in each analysis and are designated as “ is ” on the first profile in each group . the mass numbers for these standards are : m / z420 ( 2 h 6 - palmitate - c16 ), m / z308 ( 2 h 6 - octanoate - c8 ), m / z269 ( 2 h 9 - isovaleric - c5 ), and m / z237 ( 2 h 5 - propionate - c3 ), wherein m / z is the mass : charge ratio . as shown in fig8 a , when normal cells are incubated with d3 - c16 , a profile of labeled acylcarnitine intermediates can be observed from c16 down to and including c4 . the mass numbers for these 2 h 3 - labeled acylcarnitines , as methyl esters , are m / z417 ( c16 ), m / z389 ( c14 ), m / z361 ( c12 ), m / z333 ( c10 ), m / z305 ( c8 ), m / z277 ( c6 ), and m / z249 ( c4 ). when you observe the various cell lines incubated with 16 - 2 h 3 - palmitate d3 - c16 ( fig8 a - l ), virtually no oxidation occurs in cpt i cells ( fig8 b ), and a minimal amount of palmitoylcarnitine from d3 - c16 ( m / z417 ( c16 )) is observed as expected since palmitate cannot be easily converted to palmitoylcarnitine for transport into the mitochondrion . in both translocase ( fig8 c ) and cpt ii ( fig8 d ) deficient cell lines , no oxidation occurs but large quantities of labeled palmitoylcarnitine from d3 - c16 ( m / z417 ( c16 )) accumulate as a result of the presence of cpt i . the abnormal profiles of labeled acylcarnitines in vlcad - c ( fig8 e ), vlcad - h ( fig8 f ), trifunctional ( fig8 g ), lchad ( fig8 h ), etf - dh - mild ( fig8 k ), and etf - dh - severe ( fig8 l ) cell lines reflect accumulations corresponding to the carbon chain length specificity of the missing enzyme activity . in mcad ( fig8 ), oxidation clearly proceed down to the level of c8 ( m / z305 . 3 ), at which point there is a marked accumulation reflecting the substrate specificity of the missing mcad enzyme . similarly , in scad ( fig8 j ), oxidation stops at m / z249 ( 2 h 3 - butylcarnitine - c4 ). these results indicate that cpt i , translocase , cpt ii , vlcad , trifunctional , lchad , scad , and etf - dh are all required for complete oxidation of palmitate . in the case of d3 - c8 ( fig6 a - l ), the relative accumulation of m / z 305 ( 2 h 3 - octanoate - c8 ) indicates a distinct requirement for both translocase ( fig6 c ) and mcad ( fig6 i ) for complete oxidation . while commercial medium chain triglycerides ( mct ), the major component being octanoate , are considered independent of cpt i , translocase , and cpt ii , this data for 2 h 3 - octanoate - c8 indicates that mct is not an effective treatment for severe translocase deficiency . further , the data illustrates that mct would not be appropriate treatment for mcad deficiency . for cell lines treated with odd - carbon substrates d3 - c7 ( fig5 a - l ) and d3 - c9 ( fig7 a - l ), the beneficial effect is based on : ( 1 ) the absence of the diagnostic profile which could be produced to some extent from oxidation of unlabeled endogenous lipid in the culture medium ; and ( 2 ) the relative amounts of m / z235 ( 2 h 3 - propionate - c3 ) as the labeled end product of odd - carbon degradation compared to that seen in the normal control cells ( fig5 a for d3 - c7 or fig7 a for d3 - c9 ). this relative amount of m / z235 ( 2 h 3 - propionate - c3 ) is compared to the level of the internal standards at m / z269 ( 2 h 9 - isovaleric - c5 ) and m / z237 ( 2 h 5 - propionate - c3 ). for d3 - c9 , an increase was observed at m / z319 ( 9 - 2 h 3 - nonanoate ) in translocase , cpt ii , and lchad cell lines . these results indicate that translocase , cpt ii , and lchad are all required for complete oxidation of nonanoate . for d3 - c7 , the relative amounts of 2 h 3 - propionate - c3 ( m / z235 ) produced for the normal cells and cpt i , translocase , cpt ii , vlcad , trifunctional , lchad , and scad abnormal cell lines ( fig5 a - h and j ) are either comparable to or in excess of the amount seen in normal cells , indicating that beneficial oxidation of the precursor occurred . one observed exception is mcad deficiency ( fig5 ), which is expected as d3 - c7 requires mcad for oxidation , and in its absence , m / z291 ( 2 h 3 - heptanoylcarnitine - c7 ) is markedly increased . for etf - dh , no oxidation of labeled 7 - 2 h 3 - heptanoate was observed . these results indicate that , with the exception of mcad and etf dehydrogenase , n - heptanoic acid - supplemented compositions can be used in the treatment of the following fatty acid defects : translocase deficiency ; carnitine palmitoyltransferase i and ii deficiencies ; l - 3 - hydroxyacyl - coa dehydrogenase ( lchad ) deficiency ; very - long - chain acyl - coa dehydrogenase ( vlcad ) deficiency , and short chain acyl - coa dehydrogenase ( scad ) deficiency . treatment of the infant with severe neonatal translocase deficiency identified in example 1 using triheptanoin - supplemented low fat formula was successful . additionally , there is support for the correlation between the clinical response to triheptanoin therapy and the in vitro mass spectrometry analysis of the infant &# 39 ; s amniocytes . at 38 weeks gestation , delivery of the infant whose amniocytes tested positive for severe translocase deficiency as described in example 1 was accomplished . cord blood was analyzed for total and free carnitine levels as well as levels of individual acylcarnitines by tandem mass spectrometry . ( yang , et al . 1998 . “ identification of four novel mutations in patients with carnitine palmitoyltransferase ii ( cpt ii ) deficiency ,” mol genet metab 64 : 229 - 236 ). maternal blood at the time of delivery was also assayed for these same levels . results confirmed that the infant suffered from severe translocase deficiency . within the first twelve hours after delivery , a low fat formula supplemented with triheptanoin was fed to the infant via a nasogastric tube . subsequent feedings with the triheptanoin - supplemented formula were given at the same frequency as any full - term infant . supplements of carnitine , biotin , and cyanocobalamin were not required . arterial blood gases ( abg &# 39 ; s ), electrolytes , serum urea nitrogen ( bun ), creatinine , ammonia , glucose , serum creatine phosphokinase ( cpk ), alt , ast , hemoglobin ( hgb ), and hematocrit ( hct ) were monitored according to standard neonatal intensive care procedures . acylcarnitines were quantified twice daily by tandem mass spectrometry . quantitative urine organic acid analysis was performed as well to monitor the amount of dicarboxylic acids present in the urine . the intervention of triheptanoin - supplemented formula was a total success in suppressing the effects of translocase deficiency . during the infant &# 39 ; s hospital stay , the various physiological parameters given above were reported within normal ranges . the infant was discharged from the hospital at 7 - 8 weeks of age exhibiting perfect dietary management with the triheptanoin - supplemented formula . during continued maintenance on the triheptanoin - supplemented formula , the infant has maintained an average weight gain per day of 35 grams per day , compared to the average weight gain of 20 - 25 grams per day for the average formula - fed infant . at four and a half months of age , the infant continued to thrive on the triheptanoin - supplemented formula , and no carnitine , biotin , or vitamin b12 supplements had been required .
a method of treating patients in need of treatment for a cardiac disorder has been found which comprises administering to the patient a seven carbon fatty acid compound or derivative thereof , wherein the compound or derivative thereof is able to readily enter the mitochondrion without special transport enzymes . a dietary formulation suitable for treatment of heart tissue in cardiac or surgical patients has been found which comprises a seven - carbon fatty acid chain , wherein the seven - carbon fatty acid chain is characterized by the ability to transverse the inner mitochondrial membrane by a transport mechanism which does not require carnitine palmitoyltransferase i , carnitine palmitoyltransferase ii , or carnitine / acylcarnitine translocase and the ability to undergo mitochondrial β - oxidation , and wherein the compound is selected from the group consisting of n - heptanoic acid or a derivative thereof , a triglyceride comprising n - heptanoic acid or a derivative thereof , and triheptanoin or a derivative thereof .