You can start with something like the WIKI:
https://wiki.dmt-nexus.m..._and_Physical_PropertiesWhat do you mean "specific survives in"? Some alkaloids will not be sensitive to degradation with high or low pH, others might. Or maybe you mean the pKa, which says in a given pH how much of a certain alkaloid will be in salt or freebase (and therefore soluble in some or another solvent) ? In that case most of that info will be in the WIKI. If more people have more information on interesting alkaloids, feel free to add there

Other resources (that we try to include in the WIKI) is merck index, pubchem, and also information from suppliers like sigma aldrich and etc (for example they might say solubility or storage conditions/sensitivities, etc)