Prc ods column

Crude K-K2 peptide dendrimers were purified on a preparative reversed phase C₁₈ column (Shimadzu, PRC-ODS column, 150×20 mm, 15 µ) using 0.1% TFA/water (solvent A) and 0.1% TFA/acetonitrile (solvent B). Linear gradient 5–60% B (Flow rate 6 mL/min over 27.5 minutes) was used for purification of the two peptide dendrimers. Analytical purity of purified BNT1 and BNTM was assessed by chromatography on a reversed phase C₁₈ column (Microsorb, 15×4.6 mm, 15 µ) using 0.1% TFA/water (solvent A) and 0.1% TFA/acetonitrile (solvent B) and running a 5–45% linear gradient over 20 minutes at a flow rate of 1 mL/min. Dual Wavelength detector was set at 214/280 nm. The identities of peptide dendrimers were confirmed by electrospray ionization mass spectrometry (ESI-MS) at ICGEB, New Delhi. Experimental conditions used during ESI-MS of BNT1 and BNTM were solvent: 50% acetonitrile/0.1% formic acid, positive ionization mode, voltage settings (4 kilowatt) and instrument Orbitrap velos pro (Thermo Fisher Scientific).

NMR spectra data were recorded on a Bruker ascend 600 spectrometer (Bruker, Karlsruhe, Germany) with TMS used as a reference. Optical rotations were measured on PerkinElmer Model 341 polarimeter (PerkinElmer, Waltham, MA, USA). UV spectrum data were acquired using HACH DR6000 UV-visible spectrophotometer (Hach, Loveland, CO, USA). IR spectra were recorded as KBr disks on PerkinElmer Spectrum 100 Series FT-IR spectrometers (PerkinElmer, Waltham, MA, USA). HRESIMS data were obtained on a LTQ Orbitrap XL™ Hybrid Ion Trap-Orbitrap FT-MS spectrometer (Thermo, Waltham, MA, USA). TLC was carried out on silica gel GF₂₅₄ plates (Yantai Institute of Chemical industry, Yantai, China) and spots were visualized by UV light (254 and/or 365 nm) and spraying with 10% H₂SO₄ followed by heating. Column chromatography was carried out using silica gel (Qingdao Haiyang Chemical Co., Ltd., Qingdao, China), MCI gel (CHP-20P, 75–150 μm, Mitsubishi Chemical Corporation, Tokyo, Japan), ODS (35–70 μm, Grace, Maryland, MD, USA), and Sephadex LH-20 (GE Healthcare Bio-Science AB, Uppsala, Sweden) as packing materials. Semi-preparative HPLC was performed on a Shimadzu instrument (Shimadzu, Tokyo, Japan) coupled to CBM-20A system controller, LC-20AP pump, SPD-M20A Photodiode Array Detector and SIL-10AP autosampler and equipped with a Shimadzu PRC-ODS column (250 mm × 20 mm i.d., 15 μm).