🔬 Lab Update: Buchi Rotovapor, Buchi Lyovapor, and Buchi Flash Chromatograph/Prep HPLC 🔬

I figured I would give another quick lab update. We got a few new things in from Buchi that we will be using a lot over the course of the year. They actually arrived a little while back, but COVID-19 has put delays on installing and using them. I've spoken a few times on here about it, but I have always been frustrated by the lack of reference standards for certain things. There are so many cool plants out there without any reference standards for their active ingredients! So we are left unable to properly standardize for the things in those plants that we want. If Sigma or USP didn't carry the standards, we were kind of out of luck. We were forced to just do extraction ratios and wait for the standards to eventually become available. Well I decided that was not a good enough solution. So now we are building out the capability in our lab for us to create our own reference standards!

Here is the Buchi C-850 dual flash chromatograph/preparatory HPLC with both UV and ELSD detector.

Many of you already know what an HPLC system is. It's a machine that uses columns and solvents to separate out compounds from each other through a liquid mobile phase. Those compounds then get detected at the other end of the column by a detector. Most of the time that is a UV detector. Normal HPLCs/UPLCs are used as a quantitative technique in a QC lab. They are there to do assays on products. Well this Buchi system is what is known as a prep HPLC system. What that means is that it still uses columns and solvents to separate compounds from each other using a liquid mobile phase. However, it is not going to a detector to just quantify like in a QC setting. It's actually collecting the compounds as them come out of the column and separating them into their own specific cartridges for later use. So let's say I wanted to make an erinacine-A standard. I would need to grow a good amount of lion's mane mycelium, then I would need to use a prep HPLC system like this Buchi one to separate it out from the other compounds, then concentrate it into a usable amount. Essentially we are using the same strategy that a normal HPLC uses to separate compounds from each other to quantify them, but now we are concentrating and storing them for further use later. If you pair this with our UPLC mass spec, we can concentrate compounds inside of plant extracts, identify exactly what they are by mass, extra verify their structure by NMR, then use those collected samples as reference standards. It will allow us to have a ton more capabilities in not only determining what specific compounds are in these plants, but also creating the ability to standardize and quantify them in QC batches. No longer will we have to wait for other labs to create standards for us. We can create our own and blaze the trail for standardizations of novel plant extracts, or novel standardizations of existing plants that others have just not thought to do!

This particular Buchi system is the top end model as well. It's not just a prep HPLC, but it is also a flash chromatograph. The concept is pretty much the same, but flash chromatography is faster and uses less solvents than prep HPLC. However, prep HPLC results in a much more pure and accurate product, but at the cost of more solvent use and more expensive columns. So having both in the same machine means we can use flash chromatography when it makes the most sense, or even as a first step, then prep HPLC for the very accurate and specific work. In addition, this Buchi machine has both a UV detector and an ELSD. I have also spoken a few times about what UV detectors can see, but essentially they can only see things with a chromophore. Essentially things that have double bonded ring structures, or long chains of double carbon bonds, have chromophores. That means that they absorb UV light. However, some compounds in plants just don't have chromophores. So the UV detector can't see them. This is where the ELSD, or evaporative light scattering detector, comes into play. This ELSD can see things without chromophores, like sugars or terpenoids. So with both detectors we can get a better picture of what is coming out of the columns. If you add in our mass spec detector to the mix, and we can get a very good view of what compounds are coming out of the columns.

Here is the Buchi Rotavapor R-300 rotary evaporation system.

So the Buchi R-300 is an automated rotary evaporator. Anyone that does synthetic chemistry or solvent extractions of botanicals will be familiar with a rotary evaporator. When you are synthesizing a chemical compound, or are doing an extraction on a plant, you are going to be using various solvents. This could just be a step in a synthesis, or the plant extraction itself. However, you need to remove those solvents once you are done. This is where the rotary evaporator comes in. This uses heat and vacuum pressure to evaporate off the solvents so that you can use whatever is left. For example, if you are doing an ethanol extraction of lemon balm, you need to remove the ethanol after the extraction is done. Then you are left with the extract itself once the extraction solvent is removed. This Buchi system is pretty much the Ferrari of rotary evaporators! You can do automated distillation. It has all sorts of sensors to detect whether the solution is foaming or within the proper temperature/pressure range. If you want to evaporate some solvents, this baby is the one you want!

Here is the Buchi Lyovapor L-200 automated lyophilizer.

Many of you will probably recognize the word lyophilize from the Ceretropic days. After a liquid phase peptide synthesis, the peptide solution is then lyophilized, or freeze dried. Lyophilizers cool the material below its triple point, causing sublimation. This preserves the material’s physical form. Essentially you are removing frozen solvents through sublimation, and any remaining water molecules through desorption. If you were to do a normal freeze cycle of something, there is a chance that the frozen water crystals would damage the compounds themselves. So in the case of peptides, water crystals can damage the peptide bonds and ruin your peptides. This is why freezing a liquid solution of peptides is not a good idea. The water crystals can break the peptide bonds. These water crystals can also damage other organic molecules as well. So lyophilizing is a way to remove the water from a sample without damaging the compounds in solution that you want to preserve. Pretty cool!

So that's a quick lab update for the latest machines we have gotten in. COVID-19 may have slowed some of our projects, but we are still pushing ahead with all our plans. These new machines are going to allow us to not only push the boundaries of botanical extracts and standardizations, but also help on some of our synthesis projects as well. We are always working on something new here, and I am excited for what is to come. Stay tuned!