Buy high-quality intermediate from China manufacturer

Fmoc-Ile-OH (CAS 71989‑23‑6), systematically named N‑α‑(9‑fluorenylmethoxycarbonyl)‑L‑isoleucine, is a standard building block for Fmoc solid‑phase peptide synthesis (SPPS). The molecule comprises an isoleucine (Ile) amino acid residue with the N‑terminal α‑amino group protected by the base‑labile 9‑fluorenylmethoxycarbonyl (Fmoc) group. Isoleucine is an essential, hydrophobic, branched‑chain aliphatic amino acid featuring a chiral center at the β‑carbon in addition to the α‑carbon, giving rise to two diastereomeric configurations (L‑ and D‑allo‑isoleucine) that must be rigorously controlled during synthesis. The Fmoc protecting group is rapidly removed under mild basic conditions (typically 20% piperidine in DMF), enabling stepwise peptide chain elongation without exposing acid‑sensitive side chains or linkages. Fmoc-Ile-OH is supplied as a high‑purity, white to off‑white crystalline powder, and serves as the indispensable building block for incorporating L‑isoleucine into synthetic peptides.

H‑Lys(Boc)‑OH (CAS 2418‑95‑3), systematically named Nε‑(tert‑butoxycarbonyl)‑L‑lysine or H‑Lys(t‑BOC)‑OH, is a lysine derivative featuring the ε‑amino group protected by the acid‑labile tert‑butoxycarbonyl (Boc) group, while the α‑amino group remains free (H‑, i.e., unprotected). The molecule comprises an L‑lysine residue with a flexible four‑methylene side chain terminating in a Boc‑protected ε‑amino group, and a free α‑amino group and free α‑carboxylic acid. This unique protection pattern — Boc on the side chain, free on the N‑terminus — makes H‑Lys(Boc)‑OH an essential building block for solution‑phase peptide synthesis, fragment condensation, and as a precursor for preparing activated esters and other lysine derivatives. The Boc group is removed under mild acidic conditions (e.g., TFA or HCl in dioxane), providing orthogonal protection when used in combination with other protecting groups such as Fmoc, Z, or Alloc.

2-Tetradecyl Oxyethanol (CAS 2136-70-1), systematically named 2-(tetradecyloxy)ethanol and also known as myristyl glycol or ethylene glycol monotetradecyl ether, is a non‑ionic surfactant characterized by a C₁₄H₂₉– aliphatic tail covalently linked to an ethylene glycol head group. The molecule features a linear saturated tetradecyl hydrocarbon chain that imparts strong hydrophobic character, paired with a short two‑carbon ethoxyethanol hydrophilic moiety terminating in a primary hydroxyl (–OH) group. This amphiphilic architecture confers pronounced surface‑active behavior: the long lipophilic tail anchors to non‑polar surfaces or associates with hydrophobic payloads, while the ethylene glycol segment solubilizes the aggregate in aqueous media through hydrogen bonding. The compact hydrophilic head — consisting of just two ethylene oxide units — creates a balanced hydrophilic‑lipophilic profile that makes 2-Tetradecyl Oxyethanol particularly effective as a co‑surfactant, dispersing aid, and wetting agent across a range of industrial and laboratory formulations. Its rigid, non‑branched alkyl chain and single hydroxyl functionality simplify reaction chemistry, allowing straightforward derivatization to sulfates, ethers, or esters when tailored surface properties are required.

Cholesteryl hemisuccinate (CHEMS) is a semi‑synthetic, anionic cholesterol ester in which the 3β‑hydroxyl group of cholesterol is esterified with succinic acid, yielding a molecular structure that retains the rigid steroidal backbone of cholesterol while introducing a titratable carboxyl group at the C3 position via a succinate linker. The ionizable carboxyl moiety (pKa ~4.5–5.5) endows Cholesteryl hemisuccinate with pH‑dependent amphiphilicity and a net anionic charge under physiological conditions, representing a fundamental departure from neutral cholesterol. The molecular architecture of Cholesteryl hemisuccinate effectively combines the membrane‑ordering properties of the sterol core with a pH‑sensitive anionic headgroup, enabling the molecule to self‑assemble into bilayers in alkaline and neutral aqueous media while undergoing a lamellar‑to‑H_II phase transition upon acidification — a conformational switching mechanism that is actively exploited in pH‑responsive liposomal drug delivery systems and membrane protein crystallization applications.

The product is AA3-DLin, an ionizable cationic lipid whose structure is rationally segmented into three functional domains: a tertiary amine headgroup that acquires positive charge in the acidic endosomal environment, biodegradable ester linkages that promote rapid hepatic clearance and minimize chronic toxicity, and two unsaturated linoleyl-derived hydrophobic tails that enhance endosomal escape through lamellar-to-inverted-hexagonal phase transition. This modular architecture allows AA3-DLin to simultaneously achieve potent messenger RNA encapsulation, efficient intracellular delivery, and a favorable safety profile, making it a representative amino-alcohol lipid for lipid nanoparticle (LNP) systems.

14,28-bis(2-hydroxy-12-methyltridecyl)-2,20,20,22,22,40-hexamethyl-21-oxa-17,25-dithia-14,28-diaza-20,22-disilahentetracontane-12,30-diol (CAS 3006860-56-3) is a highly complex, structurally unique organic molecule with an extraordinarily long carbon backbone and multiple heteroatomic functionalities. The compound features a hentetracontane (C41) alkane backbone incorporating two silicon atoms (as 20,22-disila), two sulfur atoms (as 17,25-dithia), one oxygen atom (as 21-oxa), and two nitrogen atoms (as 14,28-diaza). Two terminal substituents — 2-hydroxy-12-methyltridecyl groups — are attached at positions 14 and 28, each containing a secondary alcohol. The sila‑substituents at positions 20,20,22,22 bear hexamethyl substitution (two methyl groups per silicon atom), and the terminal ends (C2 and C40) each carry a hexamethyl‑substituted structure incorporating hydroxyl groups at positions 12 and 30.