Stereoselective Model Synthesis of the Optically Active Olivil Type of Lignan from D-Xylose

The olivil type of lignan, (2S,3R,4R)-4-benzyl-4- hydroxy-3-hydroxymethyl-2-(3,4-methylenedioxyphenyl)tetrahydrofuran, was stereoselectively synthesized from D-xylose.     

Stereoselective Synthesis of the Optically Active Samin Type of Lignan from L-Glutamic Acid

The optically active samin type of lignan, (1R,2S,5R, 6S)-6-(2-methoxy-4,5-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-2-ol, was stereoselectively synthesized from L-glutamic acid via (2R,3R)-2-[(1S and R)- 1-[(tert-butyldimethylsilyl)oxy]-1-(2-methoxy-4,5-methylenedioxyphenyl)methyl]-3-[(tert-butyldiphenylsilyl)oxy]methyl-1,4-butanediol.     

First Stereoselective Synthesis of meso-Secoisolariciresinol and Comparison of Its Biological Activity with (+) and (−)-Secoisolariciresinol

The first stereoselective synthesis of meso-secoisolariciresinol is reported. A comparison of the cytotoxic and immunosuppressive activity between meso-secoisolariciresinol and optically active secoisolariciresinols was similarly performed for the first time. Both enantiomers of secoisolariciresinol accelerated IgM production, although meso-secoisolariciresinol did not affect IgM production. Only meso-secoisolariciresinol showed cytotoxic activity.     

Triolein,as a Phagostimulant for Albino Rat

Protaminobacter ruber, having a firm cell wall, could be lyzed by treatment with glycine or penicillin. Among amino acids tested, only glycine showed an excellent effect for the lysis. The optimal amount and time of addition of glycine for the lysis were 6 mg per ml culture and 4 to 5 hr after initiation of the cultivation, respectively. Aeration was necessary for the lysis as well as the growth of P. ruber. Morphological changes during the lysis of the bacterium were confirmed by electron microscopy. Proteins and (δ-ALA dehydratase were excreted into the medium with the progress of lysis.     

Erimopyrone,a Lignan Derivative from the Liverwort Moerckia erimona

The new lignan derivative, erimopyrone, was isolated from the liverwort, Moerckia erimona. Its structure was established as [1R, 2S]-1(6-carboxy-2-oxo-2H-4-pyranyl)- 6,7-dihydroxy-1,2-dihydro-2,3-naphthalenedicarboxylic acid by spectroscopic methods.     

Synthesis of Amino Tetrahydrofuran Lignan via an N,O-Heterocyclic Compound as an Intermediate

Wrong:Fumio ISHIBASHI

Right:Fumito ISHIBASHI     

An Unusual Tetrahydrofuran Lignan from the Roots of Zanthoxylum planispinum and the Potential Anti‐inflammatory Effects

An unusual tetrahydrofuran lignin, zanthplanispine ( 1 ), together with 14 known lignans ( 2 – 15 ) were isolated from the AcOEt‐soluble fraction from the MeOH extract of Z. planispinum roots. The structures of 1 was elucidated on the basis of 1D‐ and 2D‐NMR experiments as well as HR‐ESI‐MS analysis. The known compounds were identified by the comparison of their NMR data with previously reported in the literatures. Bioassay showed that compounds 1 – 4 could inhibit nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. In particular, compound 1 showed significant inhibitory activity with an IC₅₀ value of 36.8 μm .     

(+)-Arctigenin,a lignan from Wikstroemia indica

A new lignan, (+)-aretigenin has been isolated from the roots of Wikstroemia indica (Nan-Ling-Jao-Hua) and identified as 8(R) 8′(S)-4′-hydroxy-3, 4,3′-trimethoxylignan-olid (9, 9′) on the basis of spectral evidence as well as a direct comparison with its enantiomer, (?)-arctigenin.     

(+)-Calocedrin,a lignan dihydroanhydride from Calocedrus formosana

A novel lignan dihydroanhydride, (+)-calocedrin, was isolated from the wood of Calocedrus formosana. Its structure was determined to be trans-α-(3,4-methylenedioxybenzylidene)-β-(3,4-methylenedioxybenzyl)-γ-hydroxybutanolide by spectroscopic methods. Reduction of (+)-calocedrin resulted in an optically inactive lignan lactone, (±)-hibalactone.     

(+)-Tsugacetal,a lignan acetal from Taiwan hemlock

By the evidence of ¹H and ¹³C NMR spectra, and single crystal structure determination, a novel lignan acetal, (+)-tsugacetal, isolated from Tsuga chinensis var. formosana, was found to have an α-conidendrin-related structure with an acetal methoxy group at the β-position.     

First stereoselective synthesis of (+)-magnostellin C, a tetrahydrofuran type of lignan bearing a chiral secondary benzyl alcohol

(+)-Magnostellin C, which is a tetrahydrofuran type of lignan bearing a chiral secondary benzylic hydroxy group, was stereoselectively synthesized from L-arabinose by using threo selective aldol condensation.     

Synthesis of (+)-Juvabione,a Compound with Juvenile Hormone Activity

(+)-Juvabione 1 was synthesized by employing (1R,4S,6S)-6-hydroxybicyclo[2.2.2]octan-2-one 2 as a chiral source.

(+)-Juvabione 1 shows juvenile hormone activity, and its racemate has been repeatedly synthesized.¹⁾ Optically active 1 was synthesized by Pawson et al. from (+)-limonene, ²⁾ and by Trost et al. from (+)-perillaldehyde.³⁾ However, their syntheses were not at all efficient for providing a suitable amount of optically active 1.     

Synthesis and Evaluation of Two Coumarin‐Type Derivatization Reagents for Fluorescence Detection of Chiral Amines and Chiral Carboxylic Acids

The synthesis of two fluorescent coumarin‐type chiral derivatization agents ( 4 and 11 ) is reported. A chiral side chain was introduced at position 7 of the coumarin via Mitsunobu reaction. The two coumarins bear in this side chain either a free amino group or a carboxyl group, making them useful for further transformations. Conjugates of chiral prototype drugs with 4 or 11 were prepared by amide coupling of the analyte's carboxyl group to the reagent's amine group, or vice versa. The separation of seven diastereomeric conjugates through achiral high‐performance liquid chromatography (HPLC) on a common C18 column is demonstrated. Chirality 25:957–964, 2013. © 2013 Wiley Periodicals, Inc.     

Investigation of the Aggregation Properties of a Chiral Porphyrin Bearing Citronellal Meso Substituent Groups

A new porphyrin bearing four R or S hydrogenated citronellal units directly bound to the meso positions of the porphyrin ring was synthesized and fully characterized through MALDI‐TOF, NMR, UV/Vis absorption, and fluorescence emission spectroscopies. Both enantiomers exhibit a monomeric nature in a series of organic solvents. Acting on the polarity of the solvent, i.e., increasing the amount of water in mixture with acetone, aggregation occurs, as revealed by UV/Vis absorption, fluorescence emission, and resonance light scattering. The occurrence of both H‐ and J‐type aggregates was suggested by fluorescence lifetime measurements. In contrast to the monomeric species, these aggregates exhibit CD spectra reflecting the chirality of the building blocks. AFM microscopy shows that micrometer ribbon‐like structures form by the casting solution of these porphyrins in acetone/water onto a glass surface. Chirality 27:900–906, 2015. © 2015 Wiley Periodicals, Inc.     

Prinsepiol,a lignan from stems of Prinsepia utilis

Chemical investigation of Prinsepia utilis yielded a new lignan designated prinsepiol, in addition to l-epicatechin and β-sitosteryl-β-glucoside. Prinsepiol was shown to be 1,5 - dihydroxy - 2,6 - di(4′ - hydroxy - 3′ - methoxyphenyl) - 3,7 - dioxabicyclo[3,3,o]octane, on the basis of spectral and other evidence.     

Stereoselective pharmacokinetics of [14C]-labeled KE-298, a new anti-rheumatic drug,in rats

The stereoselective pharmacokinetics of two enantiomers of [¹⁴C]-labeled KE-298 [2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanonic acid] were investigated in rats. The blood levels of radioactivity after the oral administration of (+)-(S)-[¹⁴C]KE-298 were higher than that for (−)-(R)-[¹⁴C]KE-298; the AUC of the former was approximately twice that of the latter. No significant stereoselectivity was observed in absorption rate. The tissue/plasma level ratios at 30 min after oral administration of (−)-(R)-[¹⁴C]KE-298 in the liver and kidney, the major metabolic and/or excretory organs, were 2 to 3 times higher than those for (+)-(S)-[¹⁴C]KE-298. Neither was evidence of stereoselectivity found in the excretion of radioactivity. During incubation with isolated rat hepatocytes in vitro, the metabolic rates of KE-298 enantiomers were not significantly different. Plasma protein binding 30 min after the oral administration of (+)-(S)-[¹⁴C]KE-298 and (−)-(R)-[¹⁴C]KE-298 was 99.3% and 97.0%, respectively. Comparing the unbound fraction, (−)-(R)-[¹⁴C]KE-298 was approximately 4 times higher than (+)-(S)-[¹⁴C]KE-298. In order to make clear the relationship between stereoselective pharmacokinetics and protein binding for [¹⁴C]KE-298, the comparative pharmacokinetics of (+)-(S)-[¹⁴C]KE-298 and (−)-(R)-[^14CC]KE-298 were investigated in analbuminemic rats. In these animals, no evidence of stereoselectivity was found for either blood level-time profiles or plasma protein binding. These results revealed that the stereoselective pharmacokinetics of KE-298 in rats might be due to enantiomeric differences in binding to plasma albumin. © 1996 Wiley-Liss, Inc.     

The Structure of a Novel Lignan,Phrymarolin-II from Phryma leptostachya L.

The ginsenosides in Panax ginseng have vast structural and pharmacological efficacies. We covalently conjugated polyethylene glycol on the surface of CK (PEG-CK) through an acid-labile ester-linkage that showed increased solubility of CK. HPLC analysis showed that the release of CK was enhanced at acidic pH 5, whereas it was dramatically decreased at physiological pH 7.4. This might enhance the efficacy of CK.     

First Synthesis of (±)-Basidifferquinone C,an Inducer for Fruiting-Body Formation in Polyporus arcularius

Basidifferquinones, isolated from Streptomyces sp., are potent inducers of fruiting-body formation in the basidiomycete, Polyporus arcularius. The first synthesis of (±)-basidifferquinone C was accomplished by starting from 3,5-dihydroxy-2-naphthoic acid.     

Synthesis,Antimicrobial Activities,and Molecular Docking Studies of Dihydrotriazine Derivatives Bearing a Quinoline Moiety

In this article, three series of dihydrotriazine derivatives bearing a quinoline moiety ( 5a , 5b , 8a – 8c , and 9a – 9m ) have been designed, synthesized, and evaluated as antibacterial agents. Compounds 8a – 8c were found to be the most potent of all of the compounds tested with an MIC value of 1 μg/mL against several Gram‐positive (S. aureus 4220 and MRSA CCARM 3506) and Gram‐negative (E. coli 1924) strains of bacteria. In addition, 3‐[4‐amino‐6‐(phenethylamino)‐2,5‐dihydro‐1,3,5‐triazin‐2‐yl)‐6‐[(3‐chlorobenzyl)oxy]quinolin‐2‐ol ( 8a ) showed potent inhibitory activity (MIC=2 μg/mL) against Pseudomonas aeruginosa 2742, indicating that its antibacterial spectrum is similar to those of the positive controls gatifloxacin and moxifloxacin. Structure‐activity relationships (SAR) analyses and docking studies implicated the dihydrotriazine group in increasing the antimicrobial potency of the quinoline compounds. In vitro enzyme study implied that compound 8a also displayed DHFR inhibition.