Alkaloids 2 Animals 2 Aplidium meridianum 2 Constant neutral loss 2 Indole Alkaloids 2 Indole alkaloids 2 Marine natural products 2 Meridianins 2 Molecular Structure 2 Tandem Mass Spectrometry 2 Tandem mass spectrometry 2 Urochordata 2 alkaloid derivative 2 article 2 controlled study 2 drug identification 2 drug isolation 2 drug structure 2 electrospray mass spectrometry 2 infrared spectrophotometry 2 marine species 2 meridianin F 2 meridianin g 2 nonhuman 2 proton nuclear magnetic resonance 2 tandem mass spectrometry 2 ultraviolet spectrophotometry 2 unclassified drug 2