Early enteral nutrition with arginine compensates for negative nitrogen balance in patients undergoing curative total gastrectomy.

The effects of early enteral arginine-rich nutrition (EAN) were analyzed among patients undergoing curative-intent total gastrectomy for gastric cancer. There were 19 patients in this prospective study, all randomly assigned to either a parenteral nutrition (PN) group or an EAN group for the first seven days after surgery. The EAN group received 1.8-fold greater arginine (10.1 g/day) compared with the PN group, which was administered through an enteral tube inserted into the jejunal loop. Both groups were provided almost identical amounts of total amino acids (54 g/day), and the total energy was set at 65% of the total requirement (25 kcal/kg/day). No significant differences were observed between the two groups in postoperative complications, length of hospital stay, oral intake, nutritional status, or body weight. The serum arginine profile was similar in the two groups, as it decreased significantly on postoperative day (POD) 1, and gradually returned to preoperative levels by POD 7. The nitrogen balance remained negative until POD 7 in the PN group, but turned neutral at POD 7 in the EAN group. While we could not confirm body weight loss improvement, these results suggested that early arginine-rich enteral nutrition could improve the nitrogen balance after total gastrectomy. J. Med. Invest. 70 : 325-333, August, 2023.

Effects of methylation of arginine residue 83 on the enzymatic activity of human arsenic (+3 oxidation state) methyltransferase.

Arsenic (+3 oxidation state) methyltransferase is an enzyme responsible for arsenic methylation, and it requires S-adenosyl-methionine (SAM) as a coenzyme. We here generated two mutants to clarify the role of the highly conserved 83rd arginine residue (Arg83) in Motif I, the SAM-binding domain, of human AS3MT. When the AS3MT activity was compared between the mutants and the wild type (WT) recombinant protein, little activity was detected in the glycine mutant (Arg83Gly) or lysine mutant (Arg83Lys). When we examined the ability of transfected HEK293 cells exposed to arsenite to methylate arsenic, the methylation ability was significantly reduced in Arg83Gly compared to the WT, but was not significantly different between Arg83Lys and WT. Western blot analysis of the recombinant WT and Arg83Gly with an antibody that recognizes methylated Arg showed that an Arg residue in the WT was mono- and di-methylated, but not in Arg83Gly. Furthermore, a peptide containing dimethylated Arg83 was detected by MALDI-TOF/MS of the WT digested with chymotrypsin. These results indicate that AS3MT maintains its enzymatic activity through the methyl modification of Arg83.

Chemical Compositions of Eupatorium heterophyllum Leaf Samples from Yunnan and Sichuan Provinces of China-Isolation of 13 New Sesquiterpene Lactones.

Eight samples of Eupatorium heterophyllum leaves were collected at different locations in Yunnan and Sichuan provinces in China, and their chemical constituents were investigated. Thirteen previously undescribed sesquiterpene lactones-seven germacranolides, three eudesmanolides, two guaianolides, and a 2-norelemanolide-were isolated, and their structures were elucidated based on extensive spectroscopic analyses. The major constituents in the six samples from northwestern Yunnan and Sichuan are hiyodorilactones A and B, whereas that in the two samples from the region near Kunming, Yunnan is eupatoriopicrin. These results and previously reported results suggest the presence of locality-dependent intra-specific diversity in the chemical constituents of E. heterophyllum leaves.

Anchietins A-E: 30-norfriedelane-type triterpenes from Anchietea pyrifolia.

Five undescribed norfriedelane triterpenoids, anchietins A-E, along with three known norfriedelane triterpenoids, 21ß-hydroxycaloncobalactone, and welwitschiilactones B and C, were isolated from the vine of Anchietia pyrifolia. The compounds were characterized by spectroscopic and crystallographic methods, including 2D NMR spectroscopy and single crystal X-ray crystallography. The isolated compounds were evaluated for the cytotoxic activity against HeLa and HL60 cells and for the inhibitory activity against lipopolysaccharide-induced NO production. Further, inhibitory effects on the inducible nitric oxide synthase mRNA expression levels were also assessed.

Chemical and Genetic Diversity of Ligularia kanaitzensis in the Hengduan Mountains Area. Chemical Relationship with L. subspicata.

Root chemicals and the sequences of the internal transcribed spacers (ITSs) were analyzed for 9 Ligularia kanaitzensis and 3 L. subspicata samples collected in northwestern Yunnan and southwestern Sichuan, China. Subspicatins A and C were isolated from two L. kanaitzensis samples. Introgression of genes responsible for these compounds from L. subspicata was suggested by their strong connection with L. subspicata/L. lamarum and the geographical proximity of the samples to L. subspicata. DNA analysis of a set of 27 L. kanaitzensis samples including those analyzed previously showed that they belong to two clades, designated A and B. Together with the presence/absence of furanoeremophilane, the 27 samples were sorted into three groups: clade A/furan, clade B/furan, and clade B/non-furan. The ancestral plant presumably belonged to clade B/non-furan, because furanoeremophilanes are biosynthesized from eremophilan-8-ones. 1ß-Angeloyloxyfukinone, a likely intermediate between fukinone and subspicatin C, was isolated for the first time. This finding allowed us to propose plausible biosynthetic pathways of subspicatins A and C.

Sulfated vizantin causes detachment of biofilms composed mainly of the genus Streptococcus without affecting bacterial growth and viability.

BACKGROUND: Sulfated vizantin, a recently developed immunostimulant, has also been found to exert antibiofilm properties. It acts not as a bactericide, but as a detachment-promoting agent by reducing the biofilm structural stability. This study aimed to investigate the mechanism underlying this activity and its species specificity using two distinct ex vivo oral biofilm models derived from human saliva. RESULTS: The biofilm, composed mainly of the genus Streptococcus and containing 50 µM of sulfated vizantin, detached significantly from its basal surface with rotation at 500 rpm for only 15 s, even when 0.2% sucrose was supplied. Expression analyses for genes associated with biofilm formation and bacterial adhesion following identification of the Streptococcus species, revealed that a variety of Streptococcus species in a cariogenic biofilm showed downregulation of genes encoding glucosyltransferases involved in the biosynthesis of water-soluble glucan. The expression of some genes encoding surface proteins was also downregulated. Of the two quorum sensing systems involved in the genus Streptococcus, the expression of luxS in three species, Streptococcus oralis, Streptococcus gordonii, and Streptococcus mutans, was significantly downregulated in the presence of 50 µM sulfated vizantin. Biofilm detachment may be facilitated by the reduced structural stability due to these modulations. As a non-specific reaction, 50 µM sulfated vizantin decreased cell surface hydrophobicity by binding to the cell surface, resulting in reduced bacterial adherence. CONCLUSION: Sulfated vizantin may be a candidate for a new antibiofilm strategy targeting the biofilm matrix while preserving the resident microflora.

Arsenite suppresses the transcriptional activity of EVI1 through the binding to CCHC-type Zn finger domain.

Transcription factor EVI1 is essential for normal hematopoiesis in embryos but is aberrantly elevated in bone marrow cells of myelodysplastic syndrome (MDS) patients. EVI1 and its downstream GATA-2 appear to be a possible therapeutic target of MDS. Here we found that treatment of EVI1-expressing K562 cells with arsenite (As(III)) reduced the mRNA and protein levels of EVI1 and GATA-2. A gel shift assay using the nuclear extract of K562 cells showed that As(III) suppressed the DNA-binding activity of EVI1. The DNA-binding activity of the recombinant EVI1 protein was also suppressed by As(III) but was recovered by excess amounts of dithiothreitol, suggesting the involvement of cysteine residues of EVI1. Since the 7th Zn finger domain of EVI1, having a motif of CCHC, is known to be involved in DNA-binding, the synthetic peptide of 7th Zn finger domain was reacted with As(III) and subjected to MALDI-TOF-MS analysis. The results showed that As(III) binds to this peptide via three cysteine residues. As(III)-induced reduction of the DNA-binding activity of the recombinant EVI1 was abolished by the mutations of each of three cysteine residues to alanine in the 7th Zn finger domain. These results demonstrate that As(III) causes the down-regulation of EVI1 and GATA-2 by inhibiting the transcriptional activity of EVI1 through the binding to the cysteine residues of CCHC-type Zn finger domain.

Dinorcassane Diterpenoid from Boesenbergia rotunda Rhizomes Collected in Lower Myanmar.

A new dinorcassane diterpenoid, seikphoochinal A (1), and four known compounds, pinostrobin (2), 4',7-dimethylkaempferol (3), and galanals A (4) and B (5), were isolated from the chloroform-soluble crude extract of wild type Boesenbergia rotunda rhizomes collected in Lower Myanmar. The chemical structures of these compounds were identified, using a combination of spectroscopic methods. The presence of the diterpenoids 1, 4, and 5 demonstrated the structural diversity of wild type B. rotunda. Among the isolates, compounds 4 and 5 exhibited significant antiproliferative activities against a small panel of human cancer cell lines, including lung (LK-2, A549), stomach (ECC4), breast (MCF7), cervix (HeLa), and prostate (DU145).

Safety Assessment of Bangle (Zingiber purpureum Rosc.) Rhizome Extract: Acute and Chronic Studies in Rats and Clinical Studies in Human.

Bangle (Zingiber purpureum Rosc.) rhizome extract (BRE) contains phenylbutenoid dimers (banglenes), which exert neurotrophic effects and possess the potential capability to regenerate hippocampal neurons in mice. The acute and chronic oral toxicities of BRE powder were evaluated in Sprague-Dawley rats. A dose of BRE powder was estimated to be higher than 2000 mg/kg containing BRE 534 mg/kg as minimum lethal dose in a single-dose oral toxicity study. The no-observed-adverse-effect-level for the BRE powder was 1000 mg/kg/day (BRE 267 mg/kg) in the 90 day oral toxicity study. Four week clinical studies of BRE tablets in humans suggested that the ingestion of BRE tablets within 850 mg/man/day (BRE 227 mg/man/day) was safe for at least 1 month and in a usual manner. The C max, t max, and AUC of cis- and trans-(E)-3-(3,4-dimethoxyphenyl)-4-[(E)-3,4-dimethoxystyryl]cyclohex-1-enes (c- and t-banglenes) were calculated after the ingestion of BRE tablets (BRE 227 mg) and were 17.73 and 22.61 ng/mL, 1.8 and 1.8 h, and 71.47 and 95.53 ng/mL/h, respectively.

Diversity of Secondary Metabolites in the Liverwort Syzygiella rubricaulis (Nees) Stephani (Jamesoniellaceae, Marchantiophyta) from Neotropical High Mountains.

In order to evaluate the chemical diversity of Syzygiella rubricaulis (Nees) Stephani, a species with a disjunct distribution in the neotropical high mountains, a phytochemical study was carried out with samples from 12 different populations of different altitudes from four South American countries. The chemical profiles of lipophilic extracts were analyzed by GC/MS for each population and 50 different compounds were found with the predominance and richness of sesquiterpenes. The majority of the compounds were found only in one population and the total number of substances ranged from 1 to 15 among the populations, but these numbers were not correlated with altitude, and characterize each population as distinct, based on similarity analysis. The qualitative and quantitative variations of metabolites found are a response to different conditions, under which they live, mostly likely altitudinal conditions. Further studies on the quantification of these chemicals may provide information on their ecological roles and importance for the distribution of S. rubricaulis at different altitudes. Despite the known richness of secondary metabolites produced by bryophytes, they are still poorly explored in the context of the ecological expressions.

Eremophilanes from Ligularia hookeri Collected in China and Structural Revision of 3ß-Acyloxyfuranoeremophilan-15,6-olide.

Chemical constituents of Ligularia hookeri (Asteraceae) collected in Yunnan and Sichuan Provinces in China were examined for the first time. Seven furanoeremophilanes, five of which were new, as well as known bisabolane- and eudesmane-type sesquiterpenoids, were isolated. Spectroscopic evidence indicates that the previously reported 3ß-(2'-methylpropenoyloxy)furanoeremophilan-15,6ß-olide should be revised to 3ß-(2'-methylpropenoyloxy)furanoeremophilan-15,6α-olide.

Tetrahydrofuran lignans: Melanogenesis inhibitors from Premna integrifolia wood collected in Myanmar.

Two new tetrahydrofuran lignans, taungtangyiols A (1) and B (2), and eight known furofuran lignans (3-10), were isolated from the chloroform extract of Premna integrifolia wood collected in Myanmar. Their structures were elucidated by extensive spectroscopic techniques. The X-ray crystal structure of 1 clearly indicated its relative configuration. Taungtangyiols A (1) and B (2) inhibited the deposition of melanin in B16F10 mouse melanoma cells, with IC50 values of 50.7 and 40.9 µM, respectively, without notable cytotoxicity. An SAR study demonstrated that the furofuran and dioxymethylene moieties of the lignans play a vital role in inhibiting melanogenesis.

Terpenoids and Phenylpropanoids in Ligularia duciformis, L. kongkalingensis, L. nelumbifolia, and L. limprichtii.

The diversity in root chemicals and evolutionally neutral DNA regions in the complex of Ligularia duciformis, L. kongkalingensis, and L. nelumbifolia (the d/k/n complex) was studied using eight samples collected in central and northern Sichuan Province of China. Cacalol (14) and epicacalone (15), rearranged eremophilanes, were isolated from the complex for the first time. Two new phenylpropanoids were also obtained. Seven of the eight samples produced phenylpropanoids and the other produced lupeol alone. Two of the seven samples also produced furanoeremophilanes or their derivatives and one produced oplopanes. The geographical distribution of the sesquiterpene-producing populations suggests that the production of sesquiterpenes evolved independently in separate regions. L. limprichtii collected in northern Sichuan was also analyzed and its chemical composition and the sequence of internal transcribed spacers (ITSs) in the ribosomal RNA gene cluster were found to be similar to that in the d/k/n complex and L. yunnanensis, which are morphologically similar.

Labdane diterpenoids from Curcuma amada rhizomes collected in Myanmar and their antiproliferative activities.

Four new labdane diterpenoids, 12ß-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (1), (E)-15-ethoxy-15-methoxylabda-8(17),12-dien-16-al (2), (E)-15α-ethoxy-14α-hydroxylabda-8(17),12-dien-16-olide (3), and 15-ethoxy-12ß-hydroxylabda-8(17),13(14)-dien-16,15-olide (4) were isolated from the methanol extract of Curcuma amada rhizomes collected in Myanmar, together with 13 known analogs. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were evaluated for their antiproliferative activities against a small panel of five different human cancer cell lines (A549, human lung cancer; HeLa, human cervical cancer; MCF7, human breast cancer; PANC-1 and PSN-1, human pancreatic cancer). Among the isolates, compounds 2-4, 7, 8, 12, and 17 showed mild antiproliferative activities with IC50 values ranging from 19.7 to 96.1µM. (E)-14-Hydroxy-15-norlabda-8(17),12-dien-16-al (11) exhibited strong antiproliferative activities selectively against HeLa, PANC-1, and PSN-1 cells, with IC50 values of 5.88, 1.00, and 3.98µM, respectively. These potencies were comparable to those of the positive control, 5-fluorouracil.

Synthesis and evaluation of c-di-4'-thioAMP as an artificial ligand for c-di-AMP riboswitch.

Cyclic-di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger that binds to an RNA receptor called riboswitch and regulates its downstream genes involving cell wall metabolism, ion transport, and spore germination. Therefore, the c-di-AMP riboswitch can be a novel target of antibiotics. In this study, we synthesized c-di-4'-thioAMP (1), which possesses a sulfur atom instead of an oxygen atom in the furanose ring, as a candidate of a bioisoster for natural c-di-AMP. The resulting 1 bound to the c-di-AMP riboswitch with a micromolar affinity (34.8µM), and the phosphodiesterase resistance of 1 was >12-times higher than that of c-di-AMP. Thus, 1 can be considered to be a stable ligand against a c-di-AMP riboswitch.

Chemical constituents of hybrids of Ligularia cyathiceps and L. lamarum/L. subspicata collected in China: Structures of subspicatins M, N, O1, and O2, and related compounds.

Three natural hybrids and an introgressed individual of Ligularia were evaluated based on a combination of morphology, root chemicals, and nucleotide sequences of evolutionally neutral regions to understand the chemical outcomes of hybridization and introgression. Six previously undescribed eremophilane sesquiterpenes were isolated from hybrids between L. cyathiceps and L. lamarum/L. subspicata, and benzofurans were isolated from L. subspicata for the first time. Their structures were elucidated based on spectroscopic analyses. Some compounds produced by hybrids have not been detected in either parental species, indicating that the metabolic profile was altered by hybridization and introgression.

In Vitro Antitrypanosomal Activity of the Secondary Metabolites from the Mutant Strain IU-3 of the Insect Pathogenic Fungus Ophiocordyceps coccidiicola NBRC 100683.

During the search for new antitrypanosomal drug leads, four antitrypanosomal compounds, of three depsipeptides and one nortriterpenoid, were isolated from cultures of the mutant strain IU-3 of the insect pathogenic fungus Ophiocordyceps coccidiicola NBRC 100683. Their structures were identified by the analysis of high resolution-electron ionization (HR-EI)-MS and HR-FAB-MS, and (1)H- and (13)C-NMR spectra, including extensive two dimensional (2D)-heteronuclear NMR experiments, and comparison with literature data for destruxin A (1), destruxin B (2), destruxin E chlorohydrin (3) and helvolic acid (4). Compounds 1-4 showed in vitro antitrypanosomal activity against Trypanosoma brucei brucei GUTat3.1 with IC50 values of 0.33, 0.16, 0.061 and 5.08 µg/mL, respectively.

Two new cyclopentenones and a new furanone from Baeckea frutescens and their cytotoxicities.

Two new cyclopentenones, frutescencenones A (1) and B (2), and a new furanone derivative, frutescencenone C (3), together with two known cyclopentenones (4 and 5), were isolated from the leaves of Baeckea frutescens. Their structures were deduced by comprehensive spectroscopic analyses, including 1D and 2D NMR, and HREIMS data. Frutescencenone A (1) showed moderate growth inhibitory activity against human lung A549, pancreatic PSN-1, and breast MDA-MB-231 cancer cell lines, with IC50 values of 36.3µM, 38.2µM, and 29.3µM, respectively. In contrast, frutescencenone C (3) showed selective cytotoxic activity against PSN-1, with an IC50 value of 20.1µM.

Chemical Constituents in Hybrids of Ligularia tongolensis and L. cymbulifera: Chemical Introgression in L. tongolensis.

Two samples with morphologies intermediate between Ligularia tongolensis and L. cymbulifera were collected in Desha, Sichuan Province, and one, in Pachahai, Yunnan Province, P. R. China. The DNA sequencing confirmed that the samples were hybrids of the two species. Tetradymol (1), the major compound of L. cymbulifera not found in L. tongolensis, was isolated from the hybrid samples collected at both locations, while furanoeremophilan-15-oic acid derivative 4, a compound characteristic to L. tongolensis, was found in the Pachahai hybrid but not in the Desha hybrids. Thus, the chemical consequence of hybridization can be variable. In addition, analysis of L. tongolensis samples at Pachahai indicated that introgression has been a mechanism of generating chemical diversity in the plant. Eleven compounds including three new ones were isolated.

Chemical Lineages of Ligularia fischeri.

Six Ligularia fischeri samples, two from Sichuan (samples 1 and 2) and four from Chongqing (samples 3-6), were examined for root chemicals and the DNA sequence of the internal transcribed spacers of the ribosomal RNA gene. Samples 2 and 3 contained benzofurans. The isolation of benzofurans shows that the chemical diversity in L. fischeri is higher than previously reported. Samples 1, 4, 5, and 6 contained eremophilanes. However, the compounds were different between sample 1 and samples 4-6, indicating variation within eremophilane producers. DNA data indicated that introgression could be a mechanism of benzofuran production in sample 2 and that sample 1 and samples 4-6 were genetically separate.