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The origins of tannins and flavonoids in black-wattle barks and heartwoods, and their associated "non-tannin" components.

1. The distributions of flavonoid, carbohydrate, amino acid and imino acid components in the leaves, twig bark, stem bark, root bark and heartwoods of the black-wattle tree were compared by paper chromatography after their isolation from specific portions of the tree. 2. Wattle leaves contain mainly myricitrin, (+)-gallocatechin, an unknown myricetin glycoside and leuco-delphinidin tannins, together with smaller amounts of (+)-catechin, quercitrin and other flavonol glycosides. These are prominent in the twig bark, but decline progressively with age in the stem bark and are absent from root bark. 3. The non-phenolic components of the mature stem bark were shown to be (+)-pinitol, sucrose, glucose, fructose, l(-)-pipecolic acid, trans-4-hydroxy-l(-)-pipecolic acid, alpha-alanine, arginine, aspartic acid, glutamic acid, l(-)-proline, serine, a ;steroid' alcohol and a long-chain beta-diketone. 4. Wattle bark and heartwood ;tannins' consist of the analogues of closely related prototypes with common origins in the vascular tissues of the bark. Leaf ;tannins' are superimposed on the bark components mainly during the initial stages of bark growth. 5. Origins of the pipecolic acids and the transformations of carbohydrates in the sap- and heart-woods are discussed.

Amino Acids↗

The significance of hyperpipecolatemia in Zellweger syndrome.

The plasma pipecolic acid concentration in two newborn infants with Zellweger syndrome at ages 4 and 10 days were 7.8 and 7.7 microM. Reported concentrations from this laboratory for normal newborn infants averaged 12 microM +/- 5.6 (SD). Both patients had the facies and severe hypotonia characteristic of the disease. Autopsy examination at age 6 days in one of these patients revealed the developmental microscopic abnormalities in brain, liver, and kidney that are associated with Zellweger syndrome. In three additional patients ages 3 1/2 weeks, 2 months, and 2 months, the pipecolic acid concentrations were 15, 17, and 25 microM. The concentrations increased to distinctly pathological levels on subsequent assays at a later age. It is concluded that the hyperpipecolatemia in Zellweger syndrome occurs postpartum and that the plasma concentrations may not be diagnostic early in life. The major manifestations of the disease, already evident at birth, cannot be attributed to pipecolatemia. Currently available data do not exclude the possibility of pipecolic acid accumulation in the brain where it has been reported to be a major metabolite of lysine. Hyperpipecolatemia of considerable degree is also consistently found in familial hyperlysinemia where it appears to be benign.

Abnormalities, Multiple↗

D-amino acid levels in human physiological fluids.

Plasma, urine, cerebrospinal fluid (CSF), and amniotic fluid were examined to determine whether free D-amino acids were present and if so at what levels. It was found that D-amino acids exist in all physiological fluids tested, but that their level varied considerably. The lowest levels of D-amino acids were usually found in amniotic fluid or CSF (almost always < 1% of the corresponding L-amino acid). The highest levels were found in urine (usually tenth percent to low percent levels). Pipecolic acid seemed to be different from the other amino acids tested in that it was excreted primarily as the D-enantiomer (often > 90%). Correspondingly high levels of D-pipecolic acid were not found in plasma. Some of the trends found in this work seemed to be analogous to those found in a recent rodent study.

Adult↗

Design of potent bivalent thrombin inhibitors based on hirudin sequence: incorporation of nonsubstrate-type active site inhibitors.

Hirudin from medicinal leech is the most potent and specific thrombin inhibitor from medicinal leech with a K(i) value of 2.2 x 10(-14) M. It consists of an active site blocking moiety, hirudin1-48, a fibrinogen-recognition exo-site binding moiety, hirudin55-65, and a linker, hirudin49-54, connecting these inhibitor moieties. Synthetic inhibitors were designed based on the C-terminal portion of hirudin. The bulky active site blocking moiety, hirudin1-48, was replaced by small nonsubstrate-type active site inhibitors of thrombin, e.g., dansyl-Arg-(D-pipecolic acid). The linker moiety was replaced by omega-amino acids of (12-aminododecanoic acid)-(4-aminobutyric acid), and hirudin55-65 was used as a fibrinogen-recognition exo-site binding moiety in most of the inhibitors. The crystal structure of the inhibitor in complex with human alpha-thrombin showed that dansyl, Arg, and D-pipecolic acid of the active site blocking moiety occupy S3, S1, and S2 subsites of thrombin, respectively, and were therefore designated as P3, P1, and P2 residues. The use of dansyl-Arg-(D-pipecolic acid) improved the affinity (K(i)) of the inhibitor 10-100-fold (down to 1.70 x 10(-11) M) compared to that of the similar compounds having D-Phe-Pro-Arg as their substrate-type inhibitor moiety (K(i) = 10(-9)-10(-10) M). The linker connected to P2 residue eliminated the scissile peptide bond. The inhibitor was also stable against human plasma proteases. Further inhibitor design revealed that the toxic dansyl group could be replaced by 4-tert-butylbenzenesulfonyl group and 1- or 2-naphthalenesulfonyl group for in vivo studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

Pathologic alterations in the brain and liver in hyperpipecolic acidemia.

Pipecolic acid is a cyclic secondary imino acid produced in the metabolism of lysine. The metabolic role and fate of pipecolic acid in the human central nervous system are largely unknown. The biochemical defect in two brothers, both less than two years of age, with minor dysmorphic features, progressive neurological dysfunction, and hepatomegaly was identified as hyperpipecolatemia. At autopsy, the older brother's brain weight was increased, with bilateral pallor of the putamen. Distinctive changes included accumulation of 1-1.5 micrometer periodic acid-Schiff (PAS) positive, diastase-resistant, Alcian blue-negative, non-lipid, non-fluorescent granules in astrocytes, satellite cells, and perivascular foot processes. Both light and electron microscopy showed total absence of these granules in neurons. In the older sibling, the liver showed micronodular cirrhosis with distinctive intrahepatocytic accumulation of 0.2-1 micrometer membrane-bound material of low electron density. Pericellular fibrosis and similar cytoplasmic inclusions were present in the liver biopsy from his brother. The distinctive astrocytic storage phenomenon and the liver changes are compared to the findings in Zellweger's syndrome and lysinuric protein intolerance, which are also associated with altered pipecolate metabolism.

Brain↗

Imino acid and related alicyclic amine levels in biological fluids.

Imino acid and related alicyclic amine concentrations in blood and urine of mammals including humans were concurrently determined by a selected ion monitoring technique. Nanomole levels of proline and pipecolic acid, and pyrrolidine and piperidine as well, were found in human urine. Proline levels but not pipecolic acid levels were higher in blood of humans than in urine. Pyrrolidine and piperidine levels in blood of humans were picomole levels and much lower than those in urine. Similar tendencies were also recognized when these 4 compounds were analyzed using animal blood and urine, although the levels were generally higher in animals than in humans. Significantly high concentrations of the imino acids and the amines were found also in animal semen.

Amines↗

Defective peroxisome biogenesis with a neuromuscular disorder resembling Werdnig-Hoffmann disease.

OBJECTIVE: Characterization of the defect in a patient presenting a peripheral neuropathy with atypical features of distal motor involvement mimicking Werdnig-Hoffmann disease. PATIENT: Clinical signs included generalized hypotonia and floppiness, absence of stretch reflexes, muscle wasting, lack of head control and lingual fasciculations associated with unaffected facial muscles, and normal intellectual development. RESULTS: Normal muscle histology ruled out Werdnig-Hoffmann disease. Elevated plasma concentrations of very long-chain fatty acids and bile acid intermediates combined with normal plasmalogen levels in erythrocytes suggested defective peroxisomal beta-oxidation directly demonstrated by deficient pristanic acid and partially deficient C26:0 was present oxidation in cultured fibroblasts. Severely impaired pipecolic acid oxidation in liver and phytanic acid oxidation in fibroblasts was present. On light and electron microscopy of the liver tissue, rare peroxisomal membrane ghosts and trilamellar inclusions but absence of peroxisomes was noted. Immunoblot analysis revealed absence of peroxisomal beta-oxidation enzymes in liver tissue but normal results in fibroblasts. Remarkably, expression of the peroxisomal defect in fibroblasts was indicated by the finding of mainly cytoplasmatic catalase, as in liver. Preliminary studies excluded classification of this patient within the large PEX1 complementation group. CONCLUSIONS: The results suggest a novel peroxisome biogenesis disorder involving peroxisomal beta-oxidation as well as phytanic and pipecolic acid oxidation rather than an isolated defect of peroxisomal beta-oxidation. The association of a clinical picture mimicking Werdnig-Hoffmann disease with a novel peroxisomal disorder raises the question of whether investigation for peroxisomal function should be considered in every patient with an enigmatic spinal muscular atrophy-like syndrome.

Bile Acids and Salts↗

Biosynthesis of marcfortine A.

This report describes the results of a biosynthesis study of marcfortine A (MA). We report here that MA is derived from methionine, tryptophan, lysine and two isoprene units, the latter two being derived from acetic acid. From the 13C enrichment pattern of the pipecolic acid moeity we further conclude that this unit is derived from lysine via alpha-ketoglutarate. Therefore, we have accounted for the biogenesis of every carbon atom of MA and established the biosynthetic pathway for the pipecolic acid moiety of MA.

Acetates↗

Infantile Refsum's disease: biochemical findings suggesting multiple peroxisomal dysfunction.

Infantile Refsum's disease was diagnosed in three male patients, presenting with facial dysmorphia, retinitis pigmentosa, neurosensory hearing loss, hepatomegaly, osteopenia and delayed growth and psychomotor development. An elevated plasma phytanic acid concentration and a deficient phytanic acid oxidase activity in fibroblasts were found with an accumulation of very long chain fatty acids in plasma and fibroblasts. There were elevated pipecolic acid levels in plasma, urine and CSF, and abnormal bile acid metabolites in plasma. Deficient activity of acylCoA: dihydroxyacetone phosphate acyl transferase was found in thrombocytes and fibroblasts of these patients as well as an impaired de novo plasmalogen biosynthesis in fibroblasts. These biochemical abnormalities, previously described in the Zellweger syndrome, suggest multiple peroxisomal dysfunction in our patients.

Acyltransferases↗

High-performance liquid chromatography of amino acids in urine and cerebrospinal fluid.

Two different methods for analyzing amino acids by reversed-phase high-performance liquid chromatography (HPLC), both of which can separate D- and L- stereoisomers, have been used for studying the amino acid composition of cerebrospinal fluid (CSF) and urine. One method, by which Dns derivatives of amino acids are separated as mixed chelate complexes with Cu(II) and a single stereoisomer of a second amino acid, was used to analyze CSF. CSF contains ca. 10 mumole/l per amino acid, compared to 100 mumole/l in serum. The high sensitivity of fluorescence detection enabled complete analysis, starting with 50 microliter of fluid. The second method, which uses lower concentrations of both the copper and the second amino acid and detects amino acids by the change in absorbance of the copper complex, was used to measure the urine concentration of the lysine metabolite, pipecolic acid (piperidine-2-carboxylic acid), a secondary amino acid that is difficult to detect by the more usual detection methods. Our procedure involves passing urine through a cation-exchange column, collecting the fraction containing pipecolic acid, and chromatographing it on a reversed-phase HPLC column with a mobile phase containing L-aspartame and Cu(II). To assess the utility of the method, urine samples from a patient given loading doses of D- or L-isomers were analyzed. When either isomer was administered, both D- and L-isomers were detected, but in different proportions. Varying proportions and concentrations of both isomers were also detected in the urines of patients with hyperpipecolatemia from different metabolic abnormalities.

Amino Acid Metabolism, Inborn Errors↗

Stereoconvergent approach for synthesizing enantiopure 5, 6-dialkylpipecolic acids.

Investigating a general route for synthesizing pipecolic acid ) piperidine-2-carboxylic acid ( derivatives with substituents at the 3-, 4-, 5- and 6-position, we discovered a stereoconvergent process that provides an effective means for making 5, 6-dialkyl-epsilonpipecolate (Scheme 1, PhF = 9-phenylfluoren-9-yl). Hydrogenation of diastereomeric mixtures of gamma-oxo gamma-hydroxy and gamma-acetoxy alpha-N-(PhF)amino tert-butyl esters causes the eventual loss of the gamma-substituent to furnish an azadiene intermediate that can reduce diastereoselectively to 5, 6-dialkylpipecolate having the all cis relative stereoconfiguration. Five enantiopure (>94% ee) 5,6-dialkylpipecolic acids were synthesized, employing aspartic acid as an inexpensive chiral educt in this process.

Aspartic Acid↗

Synthesis and biological activities of angiotensin II, Sarilesin, and Sarmesin analogues containing Aze or Pip at position 7.

Analogues of [Sar1]angiotensin II, Sarilesin (type I antagonist), and Sarmesin (type II antagonist) with L-azetidine-2-carboxylic acid (Aze) and L-pipecolic acid (Pip) at position 7 have been prepared by the solid-phase method, purified by reverse-phase HPLC, and bioassayed in the rat uterus. Analogues of the superagonist [Sar1]ANGII with Aze or Pip at position 7 and sarcosine (Sar) or aminoisobutyric acid (Aib) at position 1 had high intrinsic activity in the rat isolated uterus assay (34-184%). Analogues of Sarilesin ([Sar1,Ile8]ANGII) with Aze or Pip at position 7 and Sar or Aib at position 1 retained high antagonist activity (pA2 = 7.1-8.3). Analogues of Sarmesin ([Sar1,Tyr-(OMe)4]ANGII) with Aze and Pip at position 7 had pA2 values of 7.4 and 6.5, respectively. [Aze7]-ANGII and [Pip7]ANGII had low activities (12% and 1%, respectively), and deletion of Sar at position 1 of Sarmesin analogues abolished binding (or affinity) as judged from pA2 values. Nuclear Overhauser effect (NOE) spectroscopy studies of [Sar1,Aze7]ANGII in DMSO-d6 have indicated a clustering of the three aromatic rings (Tyr, His, Phe) and proximity of Sar C alpha and Arg C delta protons to the Tyr/Phe ring protons. These data emphasize that replacement of Pro with the lower and higher homologs Aze and Pip does not greatly alter the structural requirements necessary for expression of agonist or antagonist activity, when sarcosine occupies position 1, but not when Asp occupies position 1, suggesting that there is an intimate relationship between the N-terminal and penultimate residues of the molecule in the biologically active conformation of the molecule.

Angiotensin II↗

Hyperpipecolic acidemia: clinical and biochemical observations in two male siblings.

Hyperpipecolic acidemia was diagnosed in two male siblings. Both infants had an unusual constellation of clinical findings including hepatomegaly, retinopathy, developmental delay, and several minor dysmorphic features. Pipecolic acid values were elevated in serum, urine, and in liver tissue, but none was detected using an automated amino acid analyzer. The older sibling died at 18 months of age. The younger sibling has been treated with a protein-restricted diet, with lowering of the serum pipecolic acid concentration. He is alive at 18 months of age; there has been no apparent progression in his liver disease or retinopathy since therapy began, but he remains developmentally delayed.

Brain Diseases↗

Ion chemistry of protonated lysine derivatives.

Protonated lysine fragments primarily by elimination of the epsilon-amino group as ammonia to form an ion of m/z 130 and to a minor extent by elimination of H2O to form an ion of m/z 129. Protonated lysine derivatives such as lysine beta-naphthylamide and H-Lys-Gly-OH show more pronounced formation of m/z 129 while protonated derivatives such as N alpha-Ac-Lys-X (X = OH, OMe, NHMe) and H-Gly-Lys-X (X = OH, NHCH2COOH) also show formation of m/z 129 in both metastable ion and collision-induced fragmentation. In both the latter systems m/z 129 is formed by sequential loss of HX followed by loss of ketene for the N-acetyl derivatives or the glycine residue for the N-glycyl derivatives. Although the m/z 129 ion is nominally an acylium ion, its metastable ion characteristics and collision-induced dissociation mass spectrum are very similar to those of protonated alpha-amino-epsilon-caprolactam. It is concluded that this lactam is formed from the lysine derivatives by interaction of the amino group of the lysine side-chain with the lysine carbonyl function as HX departs. Protonated N alpha-methyllysine and N alpha-dimethyllysine fragment exclusively by elimination of CH3NH2 and (CH3)2NH, respectively. Evidence is presented that the stable structure of the m/z 130 ion so formed is protonated pipecolic acid. Both the protonated alpha-amino-epsilon-caprolactam and protonated pipecolic acid ions fragment further primarily to [C5H10N]+ (m/z 84), a low mass ion commonly observed in the spectra of lysine-containing peptides.

Caprolactam↗

Synthesis, molecular modeling and biological evaluation of aza-proline and aza-pipecolic derivatives as FKBP12 ligands and their in vivo neuroprotective effects.

Nonimmunosuppressant ligands, exemplified by GPI 1046 (1), for the peptidyl-prolyl isomerase FKBP12 have been found to unexpectedly possess powerful neuroprotective and neuroregenerative effects in vitro and in vivo. We have extensively explored the therapeutic utility of FKBP12 ligands based on analogues of proline and pipecolic acid. As part of our ongoing program to explore novel structural classes of FKBP12 ligands, we herein wish to report a new class of FKBP12 ligands containing aza-proline and aza-pipecolic acid analogues. Details of the synthetic studies, together with biological activity will be presented.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

Hyperpipecolic acidemia associated with hepatomegaly, mental retardation, optic nerve dysplasia and progressive neurological disease.

A male infant with hyperpipecolic acidemia is described. To our knowledge this is only the second report of this disorder. As with the previous case, our patient's course was characterized by persistent hepatomegaly, severe mental retardation, progressive loss of developmental milestones and diminished visual acuity associated with nystagmus, abnormal discs and retinal changes. Death occurred at 2 years of age, following a progressive loss of neurological function. Pipecolic acid was repeatedly present in the serum at a concentrattion of 4-5 mg %. Trace amounts of this compound were also detected in the urine. In addition, an adaption of the method of Piez et al. (1956) for the direct quantitation of pipecolic acid in serum was evaluated and found to be very useful for the biochemical diagnosis of this disorder.

Amino Acid Metabolism, Inborn Errors↗

Biosynthesis of slaframine, (1S,6S,8aS)-1-acetoxy-6-aminooctahydroindolizine, a parasympathomimetic alkaloid of fungal origin. 3. Origin of the pyrrolidine ring.

The phytopathogen Rhizoctonia leguminicola has previously been shown to incorporate pipecolic acid into the piperidine alkaloids 1-acetoxy-6-aminooctahydroindolizine (slaframine) and 3,4,5-trihydroxyoctahydro-1-pyrindine. In the experiments described here, resting cultures of R. leguminicola were incubated with [1-14C]- and [2-14C]malonic acid and with [1-14C]- and [2-2H]acetic acid. Both acids were incorporated into the ring systems of both alkaloids. Mass spectrometric analysis of 2H-enriched slaframine showed that the label resides in the five-membered ring and that the methyl carbon of acetate is joined to the carboxyl carbon of pipecolate. A pipecolate-dependent decarboxylation of [1-14C]malonate was demonstrated in cell-free extracts of R. leguminicola. The results account for previously unattributed carbons in the two alkaloids and suggest the formation of an eight-carbon intermediate common to both alkaloids by acylation of malonate with pipecolic acid.

Acetates↗