There's still quite a bit of work with small molecules, including phytochemicals, but it seems more natural products work is being done in academic labs rather than industrial labs. One possible reason is phytochemical isolation is somewhat laborious compared to synthetic chemistry, with a very high probability that the isolated compound(s) aren't novel.

Another reason is that the isolated compounds often aren't specific or particularly active compared to many synthetic compounds. Aside from Mab's, computational chemistry has improved to the point that small molecules can be synthesized for a target; however, I've seen natural products used as a starting point for the medicinal chemists.

Another reason is that some places with interesting species for natural products sometimes asks for a share of the profits if the compound is sold commercially, these contracts tend to be very messy- what if the compound is only a starting point for a different set of synthetic compounds with improved activity?

Thats true, IPR and profitability mess alot with the patients benefit. Always a priority should be society rather then the personel benefits..

In continuation with answer of Jack Silver,

I think environmental factors which affect the composition of crude plant samples, stability issues after separation, quantity of sample during handling, final quantity of isolated compounds, and mostly repeatability issues of whole experiment should be the reason.

If I will collect or buy some plant material for study, it may be chances of little bit variation for each new batch. When we treated plant material with plenty of solvents, It may be possible that isolated compound is not the same as originally present in plant. But due to reaction with solvents, what come in our hand may be different.

There may be number of reasons Why focus on Phytochemical decreasing?

But I believe "Hope is endless". If we do something we will end up with many thing.

Keep working on.......

Despite the fact that plant and plant products provide greater structural diversity than standard combinatorial chemistry and are the most consistently successful source of drug leads, their use in drug discovery and production now-a-days has fallen out of favour. Reasons behind this scenario are dwindling resource of medicinal plants leading to raw material crisis, loss of phytodiversity owing to climate change, habitat loss on account of increasing population and developmental activities, variability in active phytochemicals, confusing identity, adulteration and unavailability of genuine plant material and to some extract complicated legal and regulatory norms. The aspect of concern about biodiversity is the loss of species through environmental changes and other developments. However, the number of species involved is unknown and subject to speculation. Although species are becoming extinct, there are many areas of the world and many different habitats that hold new, unusual and yet unexplored phytodiversity. With the difficulty of getting access to large tracts of biodiversity in natural habitats, several techniques have been developed to produce natural products in non-natural ways. These range from plant tissue culture to combinatorial genetics. In addition to offering a secure supply of naturally occurring metabolites, such technologies can be used to produce more diverse chemicals. With the continuing need for novel drug leads against an increasing number of ever-more challenging molecular assay targets, the chemical diversity derived from plant products will sustain its relevance to the future of drug discovery.

Phytochemistry required more tolerance, hard work starting from plant collection to establishment of structure.Organic or other branches, they have readily available procedure for synthesis. But in phytochemistry those methods may not workout. More over expertise is required to confirm the structure of the molecule.Rapid publications in other branches of chemistry is partially a reason. But our sidha and other traditional system of medicines are true. Its all nature play a vital role over synthetic one.