Heterocyclische Verbindungen aus Zuckern, III¹⁾ Substituierte Thiazolidine durch Reaktion von L‐Cystein mit Monosacchariden

Abstract

Durch Kondensation von L‐Cystein mit Monosacchariden erhält man 2‐Polyhydroxyalkyl‐thiazolidin‐carbonsäuren‐(4) (Tab.1) und daraus Peracetyl‐Verbindungen und deren Methyl‐ester (Tabb. 2 und 3). Die Reaktionsmöglichkeiten und die Struktur dieser Verbindungen werden am Beispiel der Kondensationsprodukte von L‐Cystein bzw. dessen Methylester mit D‐Galaktose und Pentaacetyl‐al‐D‐galaktose sowie ihren Umwandlungsprodukten untersucht.

Bioactive Phenolic Constituents from the Seeds of Pharbitis nil

“…19) Furthermore, the D-glucose and D-apiose were identified by GC analysis of their chiral derivatives in the acidic hydrolysate. 20,21) The HMBC spectrum showed the correlation of the apiosyl anomeric proton H-1Љ (d H 5.04) with the glucosyl C-6Ј carbon (d C 68.8) and correlation of the apiosyl H 2 -5Љ (d H 4.26, 4.24) with C-9ٞ (d C 169.5) of the trans-feruloyl group, respectively (Fig. 2).…”

Antineuroinflammatory and Antiproliferative Activities of Constituents from <i>Tilia amurensis</i>

“…9,10) Our continuing interest in bioactive constituents from T. amurensis led us to further investigate anti-neuroinflammatory metabolites of T. amurensis trunk since its MeOH extract showed anti-neuroinflammatory activity by inhibiting lipopolysaccharide (LPS)-stimulated NO production. A bioassayguided fractionation and chemical investigation of the MeOH extract resulted in the isolation and identification of a new isoflavonoid glycoside, orobol 4′-O-β-D-apiofuranosyl-(1 6)-β-D-glucopyranoside (1) and 16 known compounds (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). Here, we describe the isolation, structural elucidation, and the anti-neuroinflammatory and antiproliferative activities of the isolated compounds from the T. amurensis trunk.…”

“…Furthermore, the D-glucose and D-apiose were identified by gas chromatography (GC) analysis of their chiral derivatives in the acidic hydrolysate. 16,17) Thus, compound 1 was characterized as orobol…”

“…Excess production of NO by activated microglia induces neuronal cell death, 3,4) which consequently leads to various neurodegeneration in the CNS. Among isolates (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) from the active EtOAc-soluble fraction of T. amurensis, compounds 1-3, 6-7, 13 and 15 were determined to be the active ingredients responsible for anti-neuroinflammatory property of the EtOAc-soluble fraction. Particularly, compounds 2, 3 and 15 (relatively high-yield isolates) are possible to be main contributors to the activity.…”

“…For GC analysis, each sugar fraction was dissolved in anhydrous pyridine (100 µL), and 0.1 M L-cysteine methyl ester hydrochloride in anhydrous pyridine (200 µL) was added. 16,17) The mixture was stirred at 60°C for 1 h. Then 150 µL of HMDS/TMCS (hexamethyldisilazane-trimethychlorosilane-pyridine, 3 : 1 : 10) was added, and the mixture was stirred at 60°C for another 30 min. The precipitate was centrifuged off, and the supernatant was concentrated under an N 2 stream.…”