Elusive Toxin in Cleistanthus collinus Causing Vasoconstriction and Myocardial Depression: Detailed NMR Analyses and Biological Studies of Cleistanthoside A oleh Soosai Manickam Amirtham, Neetu Prince, Mangili Venkateswarulu, Iswar Chandra Mondal, Swetha Raman, Renu Raj, Elanchezhian Rajendran, Benjamin Jebaraj, Abirami Vaithiyalingam, Rajalakshmi Rajasegaran, Farhan Adam Mukadam, Anand Bhaskar, Subrata Ghosh, Jürgen Conrad, Uwe Beifuss, Sathya Subramani