PRESERVE: adding variable flip-angle excitation to transverse relaxation-optimized NMR spectroscopy

We introduce the "Polarization Restoring Excitation SEquence foR Versatile Experiments" (PRESERVE) pulse sequence element, allowing variable flip-angle adjustment in 2D <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi></mml:mi> <mml:mn>1</mml:mn></mml:msup> </mml:math> H- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi></mml:mi> <mml:mn>15</mml:mn></mml:msup> </mml:math> N and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi></mml:mi> <mml:mn>1</mml:mn></mml:msup> </mml:math> H- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi></mml:mi> <mml:mn>13</mml:mn></mml:msup> </mml:math> C transverse-relaxation-optimized-spectroscopy (TROSY)-type correlation experiments. PRESERVE-TROSY exploits a remarkable array of up to nine orthogonal coherence-transfer pathways, showcasing the remarkable potential of spin manipulations achievable through the design and optimization of nuclear magnetic resonance (NMR) pulse sequences.