Acetylated glucuronide triterpene bidesmosidic saponins from Symplocos glomerata

Nine new bidesmosidic 3-O-glucuronide oleanane triterpenoid saponins were isolated from the stem bark of Symplocos glomerata King along with two known saponins, salsoloside C and copteroside E, and two major lignans, (-)-pinoresinol and (-)-pinoresinol-4'-O-beta-D-glucopyranoside. The structures of the new saponins were established using one- and two-dimensional NMR spectroscopy and mass spectrometry as, 3-O-[beta-D-xylopyranosyl(1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-xylopyranosyl(1-->4)-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-xylopyranosyl (1-->4)-[2,3-O-diacetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[alpha-L-arabinopyranosyl(1-->4)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[alpha-L-arabinopyranosyl (1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-xylopyranosyl (1-->2)]-[beta-D-xylopyranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-glucopyranosyl (1-->2)]-[beta-D-xylopyranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-glucopyranosyl (1-->2)]-[alpha-L-arabinofuranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, and 3beta-O-[beta-D-xylopyranosyl(1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-morolic acid. The EtOH and EtOAc extracts of the stem bark showed no cytotoxic activity. At a concentration of 370 microg/ml, the saponin mixture showed haemolytic activity and caused 50% haemolysis of a 10% suspension of sheep erythrocytes.     

A comparative study of neurotensin inactivation by brain peptidases from different vertebrate species

The products formed from mammalian neurotensin by peptidases in two subcellular fractions from rat, mouse, dove, terrapin and goldfish brain were separated and identified using high-performance liquid chromatography. The main neurotensin metabolites were [1-8]-, [1-10]- and [1-7]-sequences; goldfish and terrapin brain fractions also produced [1-11]- and [1-12]-fragments. Avian neurotensin was cleaved by peptidases in rat and dove brain fractions to [1-8]-, [9-13]-, [1-10]- and [1-12]-fragments. Similar mechanisms of inactivation were found for both mammalian and avian neurotensins .     

Complexation of thiomalic acid with mercury (II) and lead (II) under physiological conditions

The complex formation of thiomalic acid (H3L) with Hg(II) and Pb(II) was investigated under physiological conditions of 37 degrees C and 0.15 mol dm-3 NaCl by potentiometric titrations using glass electrodes. From the analysis of the emf data in the two systems by use of computer program MIQUV it was concluded that the species formed in the two systems are [HgH4L2], [HgH3L]-, [HgH2L2]2-, [HgHL2]3-, [HgHL], [HgL]-, [HgL2]4-, [Hg(OH)L]2-, [Hg(OH)L2]5-, [PbH2L2]2-, [PbH2L]+, [PbHL2]3-, [PbHL], [PbL]-, [Pb(OH)L]2-, and [Pb(OH)2L]3-. The hydrolytic reactions of Hg(II), data on which were used in the analysis of the above system, were also studied by separate potentiometric titrations. Measurements of 13C NMR spectra of [HgL2]4- and [PbL]- and [PbHL2]3- in D2O solutions suggested that the ligand coordinates with both the metal ions through the sulfhydryl group and one of the two carboxylate groups in such a way that the five-membered chelate ring is formed within the complexes.     

Oxidation of glucose, ribose, alanine, and glutamate by Leishmania braziliensis panamensis

The metabolism of [1-14C]- and [6-14C]glucose, [1-14C]ribose, [1-14C]- and [U-14C]alanine, and [1-14C]- and [5-14C]glutamate by the promastigotes of Leishmania braziliensis panamensis was investigated in cells resuspended in Hanks' balanced salt solution supplemented with ribose, alanine, or glutamate. The ratio of 14CO2 produced from [1-14C]glucose to that from [6-14C]glucose ranged from about two to six, indicating appreciable carbon flow through the pentose phosphate pathway. A functional pentose phosphate pathway was further demonstrated by the production of 14CO2 from [1-14C]ribose although the rate of ribose oxidation was much lower than the rate of glucose oxidation. The rate of 14CO2 production from [1-14C]glucose was almost linear with time of incubation, whereas that of [6-14C]glucose accelerated, consistent with an increasing rate of flux through the Embden-Meyerhof pathway during incubation. Increasing the assay temperature from 26 degrees C to 34 degrees C had no appreciable effect on the rates or time courses of oxidation of either [1-14C]- or [6-14C]glucose or of [1-14C]ribose. Both alanine and glutamate were oxidized by L. b. panamensis, and at rates comparable to or appreciably greater than the rate of oxidation of glucose. The ratios of 14CO2 produced from [1-14C]- to [U-14C]alanine and from [1-14C]- to [5-14C]glutamate indicated that these compounds were metabolized via a functioning tricarboxylic acid cycle and that most of the label that entered the tricarboxylic acid cycle was oxidized to carbon dioxide.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cerebral Metabolism of 6–[18F]Fluoro-l-3,4-Dihydroxyphenylalanine in the Primate

The tracers 6-[18F]fluoro-L-3,4-dihydroxyphenylalanine (6-[18F]fluoro-L-DOPA) and L-[14C]DOPA were injected simultaneously into rhesus monkeys, and the time course of their metabolites was measured in the striatum and in the occipital and frontal cortices. In the striatum, 6-[18F]fluoro-L-DOPA was metabolized to 6-[18F]fluorodopamine, 3,4-dihydroxy-6-[18F]fluorophenylacetic acid, and 6-[18F]fluorohomovanillic acid. The metabolite pattern was qualitatively similar to that of L-[14C]DOPA. 6-[18F]Fluorodopamine was synthesized faster than [14C]dopamine. In the frontal cortex, the major metabolite was also 6-[18F]fluorodopamine or [14C]dopamine. In the occipital cortex, the major metabolite was 3-O-methyl-6-[18F]fluoro-L-DOPA. On the basis of these data, the images obtained with 6-[18F]fluoro-L-DOPA and positron emission tomography in humans can now be interpreted in neurochemical terms.     

Solid-state NMR structure determination of melittin in a lipid environment

Solid-state (13)C NMR spectroscopy was used to investigate the three-dimensional structure of melittin as lyophilized powder and in ditetradecylphosphatidylcholine (DTPC) membranes. The distance between specifically labeled carbons in analogs [1-(13)C]Gly3-[2-(13)C]Ala4, [1-(13)C]Gly3-[2-(13)C]Leu6, [1-(13)C]Leu13-[2-(13)C]Ala15, [2-(13)C]Leu13-[1-(13)C]Ala15, and [1-(13)C]Leu13-[2-(13)C]Leu16 was measured by rotational resonance. As expected, the internuclear distances measured in [1-(13)C]Gly3-[2-(13)C]Ala4 and [1-(13)C]Gly3-[2-(13)C]Leu6 were consistent with alpha-helical structure in the N-terminus irrespective of environment. The internuclear distances measured in [1-(13)C]Leu13-[2-(13)C]Ala15, [2-(13)C]Leu13-[1-(13)C]Ala15, and [1-(13)C]Leu13-[2-(13)C]Leu16 revealed, via molecular modeling, some dependence upon environment for conformation in the region of the bend in helical structure induced by Pro14. A slightly larger interhelical angle between the N- and C-terminal helices was indicated for peptide in dry or hydrated gel state DTPC (139 degrees -145 degrees ) than in lyophilized powder (121 degrees -139 degrees ) or crystals (129 degrees ). The angle, however, is not as great as deduced for melittin in aligned bilayers of DTPC in the liquid-crystalline state (approximately 160 degrees ). The study illustrates the utility of rotational resonance in determining local structure within peptide-lipid complexes.     

Benzyladenine and derivatives-their significance and interconversion in plants

Recently benzyladenine has been isolated as a natural cytokinin from a number of plants. The natural occurrence of this cytokinin will change the attitude with which physiologists view this hormone. This review attempts to put into context what is known about this cytokinin and its derivatives and to compare and contrast its metabolism and the function and physiological action of its various metabolites. Nothing is known about the biosynthesis of benzyladenine. Its structure would suggest that its biosynthetic pathway may differ considerably from that of zeatin and iso-pentenyladenine.Abbreviations Ade adenine - Ado adenosine - BA benzyladenine - [9R]BA BA ribonucleoside - [9R-MP]BA BA nucleotide - [9R-DP]BA BA dinucleotide - [9R-TP]BA BA trinucleotide - [3G]BA BA 3 glucoside - [7G]BA BA 7 glucoside - [9G]BA BA 9 glucoside - [9R-G]BA BA 9-ribosylglucoside - [9Ala]BA BA alanine-conjugate - (2OH)BA BA ortho-OH - (2OH)[9R]BA BA ortho-Oh-riboside - KN kinetin - [9R]KN KN ribonucleoside - DHZ dihydrozeatin - Z trans-zeatin - [9R]Z zeatin ribonucleoside - [7G]Z zeatin-7-glucoside - [9G]Z zeatin-9-glucoside - [9Ala]Z zeatin alanine-conjugate - (OG)[9R]Z O-glucoside of zeatin ribonucleoside - [9R-MP]Z zeatin nucleotide - iP iso-pentenyladenine - [9R]iP iP ribonucleoside     

Pharmacological specificity of some psychotomimetic and antipsychotic agents for the sigma and PCP binding sites

The pharmacological specificity of representative psychotomimetic agents such as phencyclidine (PCP) analogs, opiate benzomorphans and several antipsychotic agents was assessed for the sigma and PCP binding sites. In a series of binding experiments, in rat brain membranes, sigma and PCP binding sites were labeled with [3H]-1-[1-(3-hydroxyphenyl)cyclohexyl]piperidine [( 3H]PCP-3-OH), (+) [3H]-N-allylnormetazocine [(+) [3H]SKF 10047] and (+) [3H]-3-[3-hydroxy-phenyl]-N-(1-propyl)piperidine [(+) [3H]-3-PPP]. PCP analogs inhibit potently high affinity [3H]PCP-3-OH binding and (+) [3H]SKF 10047 binding, moderately the low affinity binding component of [3H]PCP-3-OH and very weakly (+) [3H]-3-PPP binding. (+)SKF 10047 and cyclazocine are potent to moderate inhibitors of (+) [3H]SKF 10047, high affinity [3H]PCP-3-OH and (+) [3H]-3-PPP binding, but extremely weak inhibitors of low affinity [3H]PCP-3-OH binding. The antipsychotic agents display high affinity for (+) [3H]-3-PPP binding sites, moderate affinity for (+) [3H]SKF 10047 sites and have no effect on either the high or low affinity [3H]PCP-3-OH binding. The present data further support the existence of multiple sigma and PCP binding sites.     

Effect of insulin and cortisol on oxidation of (1-14C)glucose, (6-14C)glucose, (1-14C)palmitate and (1-14C)leucine in the tissues of swine during the neonatal period

The intensity of [1-14C]glucose, [6-14C]glucose, [1-14C]palmitate and [1-14C]leucine oxidation and the effect of insulin and hydrocortisone on this process were studied in the brain, duodenum mucosa, liver and skeletal muscle of 1- and 5-day old piglets in vitro. Most of the studied substrates are oxidized in the tissues of 5-day piglets more intensively. Insulin stimulates oxidation of [1-14C]glucose, [6-14C]glucose and [1-14C]leucine in the brain and duodenum mucosa in 1- and 5-day old piglets, while in the liver and skeletal muscle--only in 5-day old piglets. Hydrocortisone administration enhances oxidation of [1-14C]leucine in most of the studied tissues in 1-day piglets and oxidation of [1-14C]glucose and [6-14C]glucose--in 5-day piglets. Both hormones produce no essential influence on the intensity of [1-14C]palmitate oxidation in the studied tissues of piglets or somewhat weaken it.     

Synthesis and initial PET imaging of new potential dopamine D3 receptor radioligands (E)-4,3,2-[11C]methoxy-N-4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl-cinnamoylamides

D3 receptor radioligands (E)-4,3,2-[11C]methoxy-N-4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl-cinnamoylamides (4-[11C]MMC, [11C]1a; 3-[11C]MMC, [11C]1b; and 2-[11C]MMC, [11C]1c) were synthesized for evaluation as novel potential positron emission tomography (PET) imaging agents for brain D3 receptors. The new tracers 4,3,2-[11C]MMCs were prepared by O-[11C]methylation of corresponding precursors (E)-4,3,2-hydroxy-N-4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl-cinnamoylamides (4,3,2-HMCs) using [11C]methyl triflate and isolated by the solid-phase extraction (SPE) purification procedure with 40-65% radiochemical yields, decay corrected to end of bombardment (EOB), and a synthesis time of 15-20 min. The PET dynamic studies of the tracers [11C]1a-c in rats were performed using an animal PET scanner, IndyPET-II, developed in our laboratory. The results show that the brain uptake sequence was 4-[11C]MMC > 3-[11C]MMC > 2-[11C]MMC, which is consistent with their in vitro biological properties. The initial PET blocking studies of the tracers 4,3,2-[11C]MMCs with corresponding pretreatment drugs (E)-4,3,2-methoxy-N-4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl-cinnamoylamides (4,3,2-MMCs, 1a-c) had no effect on 4,3,2-[11C]MMCs-PET rat brain imaging. These results suggest that the localization of 4,3,2-[11C]MMCs in rat brain is mediated by nonspecific processes, and the visualization of 4,3,2-[11C]MMCs-PET in rat brain is related to nonspecific binding.     

Anomeric specificity of D-glucose production by rat hepatocytes

The anomeric specificity of D-glucose metabolism in intact hepatocytes remains a matter of debate. This issue was further investigated in the present study, which is based on the quantification of the alpha- and beta-anomers of the 13C-enriched isotopomers of D-glucose generated by rat liver cells exposed to either D-[1-13C] fructose or D-[2-13C] fructose in the presence of D2O. The D-[1-13C]glucose/D-[6-13C]glucose paired ratios found in the cells exposed to D-[1-13C] fructose and the D-[2-13C]glucose/D-[5-13C]glucose paired ratios found in the cells exposed to D-[2-13C] fructose yielded a paired beta/alpha ratio averaging (mean +/- S.E.M.) 79.3 +/- 6.1%. In the case of the isotopomers of D-glucose formed by gluconeogenesis, the D-[2-13C]glucose/D-[5-13C]glucose and D-[3-13C]glucose/D-[4-13C]glucose paired ratios found in cells exposed to D-[1-13C] fructose, as well as the D-[1-13C]glucose/D-[6-13C]glucose and D-[3-13C]glucose/D-[4-13C]glucose paired ratios found in cells exposed to D-[2-13C]fructose, yielded an alpha/beta paired ratio averaging 75.0 +/- 5.8%. Last, in the cells exposed to D-[2-13C]fructose, the beta/alpha ratio for the C2-deuterated isotopomers of D-[2-13C]glucose represented 78.9 +/- 3.7% of that for the C5-deuterated isotopomers of D-[5-13C]glucose. The three values representative of the anomeric specificity of D-glucose production by liver cells were not significantly different from one another, with an overall mean value of 76.9 +/- 3.6%. These findings unambiguously document that the anomeric specificity of phosphoglucoisomerase is operative in intact hepatocytes, resulting in a preferential output of the alpha-anomer of 13C-enriched D-glucose under the present experimental conditions.     

Formation and metabolism of 3',5'-diiodothyronine and 3,5-diiodothyronine by cultured monkey hepatocarcinoma cells.

Cultured monkey hepatocarcinoma cells were incubated with [3',5'-125I] diiodo-L--thyronine and with [3,5-125I] diiodo-L-thyronine. In both instances monodeiodination as well as sulfoconjugation took place. [3.-125I] iodothyronine and [3',5'-125I] diiodothyronine were identified as metabolites of [3'-5'-125I]-L-thyroxine in the cells, but neither [3-125I]-iodothyronine nor [3,5-125I] diiodothyronine was detected after incubation of the cells with ]3,5-125I]-L-thyroxine. No products of diphenyl ether splitting were observed in the medium after incubation of the cells with either [3,5-125I] diiodo-L-thyronine or [3,5-125I]-L-thyroxine.     

Synthesis and anti-inflammatory activities of N4,N5-disubstituted-3-methyl- H-pyrazolo[3,4-c]pyridazines

The synthesis and anti-inflammatory activity of 4,5-dihydroxy-3-methyl-1H-pyrazolo[3,4-c]pyridazine (4), 4,5-dichloro-3-methyl-1H-pyrazolo[3,4-c]pyridazine (5), 4,-benzoyloxy-3-methyl-1-benzoyl-1H-pyrazolo[3,4-c]pyridazin-5yl benzoate (6), 3-methyl-N4,N5-bis(4-methylphenyl)-1H-pyrazolo[3,4-c]pyridazine-4,5-diamine (7), 4[[5-(4-carboxyanilino)-3-methyl-1H-pyrazolo[3,4-c]pyridazin-4yl]amino]benzoic acid (8), N-[5-(benzoylamino)-3-methyl-1H-pyrazolo[3,4-c]pyridazin-4-yl]benzamide (9) and 3-methyl-N4,N5-bis[4-(1H-benzimidazol-2yl)phenyl]-1H-pyrazolo[3,4-c]pyridazine-4,5-diamine (10) are being reported.     

Synthesis and characterization of new radioligands for the mammalian melanin-concentrating hormone (MCH) receptor

Melanin-concentrating hormone (MCH) is a neuropeptide present in the brain of all vertebrates. For the characterization of MCH receptors, a monoiodinated [Phe13, Tyr19]-MCH radioligand analogue was developed. The high susceptibility of [125I]-[Phe13, Tyr19]-MCH to oxidative damage and its very lipophilic nature made it necessary to develop new MCH radioligands. To increase the stability, native methionines were replaced by non-sulphur containing amino acid residues. In one analogue, the L-enantiomer of the phenylalanine residue at position 13 was substituted by the D-enantiomer, which increased the relative affinity of the ensuing [125I]-[D-Phe13, Tyr19]-MCH about 7-fold. The different analogues were iodinated by an enzymatic reaction and used for binding studies with mouse melanoma cells. [125I]-[Met(O)4,8, Phe13, Tyr19]-MCH and [125I]-[Hse4,8, Phe13, Tyr19]-MCH showed only about 19% of total binding and [125I]-[Ser4,8, Phe13, Tyr19]-MCH displayed about 44% of total binding when compared with [125I]-[Phe13, Tyr19]-MCH. Non-specific binding for all tracers was below 11% of total binding of [125I]-[Phe13, Tyr19]-MCH binding. [125I]-[D-Phe13, Tyr19]-MCH was used for saturation binding studies and revealed a KD of 122.7 +/- 15.3 pmol/l. This radioligand was further characterized by association and dissociation binding studies.     

The fractionation of the fatty acid synthetase activities of avocado mesocarp plastids.

1. The range of fatty acids formed by preparations of ultrasonically ruptured avocado mesocarp plastids was dependent on the substrate. Whereas [1-14C]palmitate and [14C]oleate were the major products obtained from [-14C]acetate and [1-14C]acetyl-CoA, the principal product from [2-14C]malonyl-CoA was [14-C]stearate. 2. Ultracentrifugation of the ruptured plastids at 105000g gave a supernatant that formed mainly stearate from [2-14C]malonyl-CoA and to a lesser extent from [1-14C]acetate. The incorporation of [1-14C]acetate into stearate by this fraction was inhibited by avidin. 3. The 105000g precipitate of the disrupted plastids incorporated [1-14C]acetate into a mixture of fatty acids that contained largely [14C]plamitate and [14C]oleate. The formation of [14C]palmitate and [14C]oleate by disrupted plastids was unaffected by avidin. 4. The soluble fatty acid synthetase was precipitated from the 105000g supernatant in the 35-65%-saturated-(NH4)2SO4 fraction and showed an absolute requirement for acyl-carrier protein. 5. Both fractions synthesized fatty acids de novo.     

Biosynthetic studies on the tropane ring system of the tropane alkaloids from Datura stramonium

Isotopic labelling experiments have been carried out in Datura stramonium root cultures with the following isotopically labelled precursors; [2H3]- [2-13C, 2H3]-, [1-13C, 18O2]-acetates, 2H2O, [2H3-methyl]-methionine, [2-13C]-phenyllactate, [3-2H]-tropine and [2'-13C, 3-2H]-littorine. The study explored the incorporation of isotope into the tropane ring system of littorine 1 and hyoscyamine 2 and revealed that deuterium from acetate is incorporated only into C-6 and C-7, and not into C-2 and C-4 as previously reported. Oxygen-18 was not retained at a detectable level into the C(3)-O bond from [1-13C, 18O2]-acetate. The intramolecular nature of the rearrangement of littorine 1 to hyoscyamine 2 is revealed again by a labelling study using [2'-13C, 3-2H]-littorine, [2-13C]-phenyllactate and [3-2H]-tropine.     

Studies on the role of 1,25-dihydroxyvitamin D in chick embryonic development

Vitamin D-deficient laying hens were repleted with 25-hydroxy[26,27-3H]vitamin D3 or 1,25-dihydroxy[26,27-3H]vitamin D3. Egg production returned to normal for both groups of hens by the third week. Eggs from hens fed either 25-hydroxy[26,27-3H]vitamin D3 or 1,25-dihydroxy[26,27-3H]vitamin D3 contained 1,25-dihydroxy[26,27-3H]vitamin D3. Eggs from hens fed 25-hydroxy[26,27-3H]vitamin D3 contained substantial amounts of 25-hydroxy[26,27-3H]vitamin D3, while those from hens fed 1,25-dihydroxy[26,27-3H]vitamin D3 contained none. Plasma from 18-day embryos from hens fed 1,25-dihydroxy[26,27-3H]vitamin D3 contained little or no 1,25-dihydroxy[26,27-3H]vitamin D3, while that from 18-day embryos from hens given 25-hydroxy[26,27-3H]vitamin D3 had normal levels of 1,25-dihydroxy[26,27-3H]vitamin D3. No eggs from hens fed 1,25-dihydroxy[26,27-3H]vitamin D3 hatched, while eggs from hens fed 25-hydroxy[26,27-3H]vitamin D3 achieved a hatchability of 90%. It appears that embryos from hens maintained on 1,25-dihydroxyvitamin D3 as their sole source of vitamin D are essentially vitamin D deficient.     

A study on the tricarboxylic acid cycle and the synthesis of acetylcholine in the lobster nerve

1. The biosynthetic origin of the amide substituent of N-(alpha-hydroxyethyl)lysergamide has been studied. 2. [1-(14)C]Acetate, [(14)C]formate, [2-(14)C]mevalonic acid lactone, [2-(14)C]indole, dl-[3-(14)C]tryptophan, dl-[3-(14)C]serine, dl-[2-(14)C]alanine and [2-(14)C]pyruvate were efficiently incorporated into the alkaloid, but not dl-[1-(14)C]alanine or [1-(14)C]pyruvate. 3. Only the dl-[2-(14)C]alanine- and [2-(14)C]pyruvate-derived alkaloid contained appreciable radioactivity in the amide substituent. 4. l-[(15)N]Alanine-derived alkaloid was shown to be specifically labelled in the amide nitrogen. However, l-[(14)C,(15)N]alanine was found to be incorporated into the methylcarbinolamide substituent with an appreciable increase in the (15)N/(14)C ratio, suggesting that alanine is not the direct precursor of this moiety.     

Identification of unprecedented purine-containing compounds, the zingerines, from ginger rhizomes (Zingiber officinale Roscoe) using a phase-trafficking approach

Three unprecedented purine-containing compounds, named [6]-, [8]-, and [10]-zingerines as they are 5-(6-amino-9H-purin-9-yl) analogs of [6]-, [8]-, and [10]-gingerols, respectively, were isolated from a methanolic extract of ginger rhizomes using a phase trafficking-based method that utilizes solid phase reagents allowing for fast and selective simultaneous separation of basic, acidic, and neutral components of natural products extracts.