Products

Fmoc-Cys(PrCOOtBu)-OH is an Fmoc-protected cysteine derivative featuring a strategically functionalized thioether side chain terminating in a tert-butyl-protected carboxyl group — specifically, a 4-(tert-butoxy)-4-oxobutyl group appended via a sulfur atom to the β‑position of the cysteine backbone. The Fmoc (9‑fluorenylmethoxycarbonyl) group temporarily masks the α-amino group for controlled stepwise elongation in solid‑phase peptide synthesis (SPPS), and is cleanly removed under mild basic conditions (typically 20% piperidine in DMF) without disturbing acid-labile side‑chain protections or the peptide‑resin linkage. Meanwhile, the tert-butyl ester at the terminus of the C3 spacer provides orthogonal carboxyl protection, allowing the side‑chain carboxylic acid to be selectively unmasked under acidic cleavage conditions (e.g., TFA) while the N‑terminal Fmoc protection remains intact. This orthogonal protection strategy is particularly valuable for the assembly of complex branched peptides, peptide–drug conjugates, and cyclic peptides where the cysteine side‑chain requires selective chemical manipulation.

With the molecular formula C₂₁H₃₈O₄S₃, MDS-06-06 is a structural isomer of the previously characterized impurity standard sharing the same empirical composition and molecular weight. The molecule contains a central ester moiety linked to multiple thioether-containing aliphatic chains, a structural arrangement that introduces both hydrophobicity and distinct UV-absorbing properties suitable for HPLC detection. The presence of three sulfur atoms embedded within saturated hydrocarbon backbones, likely in an alternative connectivity pattern compared to its isomeric counterpart, creates a distinct three-dimensional architecture that determines its unique chromatographic retention behavior. This specific arrangement of the poly-thioether scaffold, with its characteristic ester chromophore, makes MDS-06-06 a structurally distinct marker relevant to the comprehensive impurity profiling of solifenacin succinate formulations.

MDS-06-03 is a specialized pharmaceutical impurity reference standard used primarily in the development and quality control of solifenacin succinate formulations. It is a related compound or degradation product identified during stability-indicating method development. This compound functions as a key analytical marker for impurity profiling in overactive bladder medications.

The molecular architecture of MDS-07-01 (C₁₈H₃₂O₅, MW 328.44) is built around a central carbonate diester motif, where a 2-butyloctyl alkyl chain and a 2-hydroxyethyl acrylate fragment are bridged through two oxycarbonyl linkages.Telectron-deficient acrylate ester provides a chromophore for UV detection in HPLC analysis and a reactive Michael acceptor site. In contrast, the branched 2-butyloctyl group imparts significant lipophilicity (predicted density ~0.982 g/cm³) and influences the molecule‘s retention behavior on reversed-phase columns.This unique structure, connecting a reactive terminal alkene to a bulky aliphatic chain via a labile dicarbonate bridge, makes MDS-07-01 a structurally distinct marker relevant to the comprehensive impurity profiling of pharmaceutical formulations.

The molecular architecture of MDS-08-01 (C₂₃H₄₂O₆, MW 414.58) is characterized by a central butanoic acid core bearing two nonanoyloxy (pelargonate) chains connected via ester linkages at the 3- and 4-positions. The molecule features a free carboxylic acid group (pKa ~4.19), which contributes both polarity and pH-dependent ionization behavior, while the two C9 aliphatic ester chains impart significant hydrophobicity (predicted density ~1.010 g/cm³) and influence the molecule's retention characteristics on reversed-phase chromatographic systems. This unique arrangement—combining a polar acid head group with dual lipophilic nonanoyloxy tails—produces a surfactant-like amphiphilic architecture that makes MDS-08-01 a structurally distinctive marker relevant to the comprehensive impurity profiling of pharmaceutical formulations involving lipid-based intermediates or excipients.

The molecular architecture of N-[2-(Dodecyldisulfanyl)ethyl]acrylamide (C₁₇H₃₃NOS₂, MW 331.58) is characterized by three distinct functional domains connected in a linear arrangement: a reactive terminal acrylamide group, a two-carbon ethyl spacer, and a lipophilic dodecyl chain attached via a redox-sensitive disulfide (-S-S-) bridge. The acrylamide moiety at one terminus provides an electron-deficient α,β-unsaturated carbonyl system that serves as both a UV chromophore (enabling HPLC detection at approximately 210–240 nm) and a reactive Michael acceptor capable of participating in nucleophilic conjugate additions with thiols, amines, and other nucleophiles. The disulfide linkage (-S-S-) constitutes a chemically responsive structural element that remains stable under extracellular oxidizing conditions but undergoes rapid reductive cleavage in the presence of intracellular concentrations of glutathione (GSH, 1–10 mM), thereby releasing the free dodecanethiol fragment. The dodecyl (C12) alkyl chain contributes substantial lipophilicity (predicted LogP ~5.5–6.0) that dominates the molecule's reversed-phase chromatographic retention and influences its compatibility with lipid-based formulation platforms. This combination of a reactive acrylamide handle, a bioreducible disulfide linker, and a hydrophobic C12 tail makes N-[2-(Dodecyldisulfanyl)ethyl]acrylamide a structurally sophisticated building block at the interface of stimuli-responsive materials science and pharmaceutical delivery system design.