Total synthesis of xylapeptide B [Cyclo‐(L‐Leu‐L‐Pro‐N‐Me‐Phe‐L‐Val‐D‐Ala)].

Autor: Kurnia, Dessy Yulyani, Maharani, Rani, Hidayat, Ace Tatang, Al‐Anshori, Jamaludin, Wiani, Ika, Mayanti, Tri, Nurlelasari, Harneti, Desi, Supratman, Unang
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Zdroj: Journal of Heterocyclic Chemistry; Jan2022, Vol. 59 Issue 1, p131-136, 6p
Abstrakt: Xylapeptide B is a cyclopentapeptide isolated from Xylaria sp. derived from the Chinese medicinal plant Sophora tonkinensis. Xylapeptide B was successfully synthesized by a combination of solid‐ and solution‐phase, using the Fmoc strategy, and 2‐chlorotrityl chloride resin. The coupling reagent used is a combination of HBTU/HOBt to assist in the formation of amide bonds. D‐Ala was chosen as the C‐terminal because it has a small residue and can facilitate the cyclization process. Linear peptide was cleaved from the resin using a dilute acid concentration of 20% TFA in DCM because the peptide has no protecting group at the side chain. Crude linear peptide was purified by semi‐preparative RP‐HPLC using 0%–100% ACN eluent for 35 min and obtained a pure mass of 22.4 mg (18.83%). Cyclization was carried out in solution phase using HBTU (3 eq.) and DIPEA (1% v/v) in diluted concentration (1.25 mM) for 72 h at room temperature. The cyclization stage was monitored by thin‐layer chromatography (TLC). Crude xylapeptide B was purified by semi‐preparative RP‐HPLC using 30%–80% ACN eluent for 40 min, to result in 6 mg (8.91%) of the desired xylapeptide B. All synthesized products were characterized by HR‐TOFMS, 1H‐, and 13C‐NMR. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index