The syntheses of homogeneous penicillamine disulfide cross-linked polypeptides are reported. Dodecapeptides containing N-terminal, C-terminal, or N- and C-terminal Pen were serially ligated into 36 amino acid polypeptides linked through Cys-Pen, Pen-Cys or Pen-Pen disulfide bonds. Critical to the syntheses was
A new aromatic compound 3,4,5-trimethoxyphenyl-1-O-(4-sulfo)-β-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3-O-β-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on
Four new oleanane-type saponins 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyl-22-O-β,β-dimethylacryloylA1-barrigenol (1), 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol (2), 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 6)]-β-D-glucopyranosyl-21,22,28-O-triacetyl-(3β,21β,22α)-olean-12-en-16-one (3), and 3-O-β-D-glucopyranosyl-(1 → 2)-glucopyranosyl-22-O-β-D-glucopyranosylsteganogenin (4), along with the known 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol and 3-O-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucuronopyranosyloleanolic acid, were isolated from
The phytochemical study of Ornithogalum dubium Houtt. (Asparagaceae) led to the isolation of five undescribed steroidal glycosides together with two known ones. Their structures were established by using NMR analysis and mass spectrometry as (25R)-3β-hydroxyspirost-5-en-1β-yl O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside, (25S)-3β-hydroxyspirost-5-en-1β-yl O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside, (22S)-16β-[(α-L-rhamnopyranosyl)oxy]-22-hydroxycholest-5-en-3β-yl O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside
Structural analysis of oleanane-type saponins from the roots of Wisteria frutescens.
Anne-Sophie Champy et al.
Magnetic resonance in chemistry : MRC, 55(6), 595-600 (2016-11-20)
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