http://news.yahoo.com/next-mars-400-scientists-alien-road-trip-185745781.html
And some of the CARBON-BASED compounds that are, among other things, required for LIFE are compounds like:
Glycine, Alanine, Valine, Leucine, Methionine, Isoleucine, Phenylalanine, Threonine, Tryptophan, Histidine, etc.
These are among the socalled 20 "Standard Amino Acids" LIFE here on earth depend on, of course.
Glycine is found to be on meteorites and other space objects that have fallen to earth, surviving the burn-up during entry, so it is very likely Glycine will be found on Mars.
Th reason these are among the socalled Carbon-based compounds is that ALL LIFE ON EARTH as we know it, has compounds that are made up with CARBON ATOMS being the SKELETON or backbone of the molecule or compound.
From here, I would go on a limb, and argue that the chances of finding Carbon-based compounds on Mars are pretty good --- in addition to water, one Oxygen and 2 Hydrogen (notice that H20 is NOT a socalled Carbon-based compound, but it is a compound that, as far as we know, WILL PROBABLY have to have, in order for LIFE as we know it, to exist, since WATER, H20, is the BEST CHEMICAL in the known world, serving as both acid and base.... being so ideal as a liquid, it is able to disolve, on average, more substance and compounds than any other liquids....
Here's the reason, a "big picture" reasoning:
When our SOLAR SYSTEM formed, it formed from the ASHES of earlier exploding stars in our small, local patches of the MILKY WAY.... within a few light years, to a few thousand light years.... scattering their "ashes" (of the heavier elements like Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Flourine, Neon, Sodium, Magnesium, Aluminum, Iron, Copper, Nickel, Silver, Zinc, Gold, etc.) ...
And while it is true that our Sun, being so big in comparison to all other planets revolving around it, has about 99.8% of the mass of our local solar system, the "left over" traces --- or "ashes" --- that eventually formed Earth, Mars, Venus, and the other planets are still the remnants of OTHER EXPLODING STARS in our neighborhood; such traces, such ashes, don't come from our sun, which is made up of almost entirely Hydrogen atoms, from which the SUN turns (via nuclear fusion) into the slightly heavier Helium, with the by-product being the energy or "heat" given off... to sustain us here on earth...
Note that the VISIBLE universe is essentially made of HYDROGEN atoms, which came into existence from the earliest parts of the socalled Big Bang.
But OTHER elements --- the socalled HEAVIER elements --- are made ONLY when large suns, larger than our own (which, as an average sun won't go supernova), go supernova, dispersing their "ashes" (of elements) to their regions or neighborhoods, in their GALAXY...
And while most free floating Hydrogen atoms could float into space, from most surfaces (except extreme ones like the sun, with too much gravity), MOST of the other heavier elements, both as individual elements and as compounds (being "stuck" with other elements), can not and do not float into space; they, in fact, burrow deeper into the planet's surface... So most of what's found on earth here, should be found on our other sister planets around the sun... although on different planets, and in their moons, the compositions of the various elements are undoubtly are different...