by Dakota

New Streptomyces – New synthesis step – and soon, a new lab (hopefully)

January 11, 2015 in Posts, Projects by Dakota

Many a hastily packed column have been run in the past few weeks, and so to have many plates been poured.  The synthesis has been put on hold due mainly to the fact that I don’t trust working with the sodium cyanoborohydride in the 60 year old fume hoods at our lab, which sometimes when the fan cuts out, blows backwards.  The new UPLC-MS will also be going online this week so the hood where it vents to has been cleaned out to facilitate making that happen.

I ordered some Pd on carbon and will instead try to run a hydrogenation reaction.


The synthesis aside, we’ve moved forward with an experiment to isolate actinomycetes from soil, and the pictures below are of some of the isolates, as well as some of the dilution plates.  One of the pictures is of 5 Streptomyces species isolated and vertically streaked on a NA plate for assay testing against a few organisms.  The satellite colonies are actually not contaminants but places where spores fell off the cotton swab used during inoculation.  There is a lot going on right now behind the scenes and so for now I just have a bunch of pictures and not to many words.

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by Dakota

Environmental isolation of actinomycetes from terrestrial and saline soil

December 21, 2014 in Projects by Dakota

Being part way through the awesome book Experiment Eleven has inspired me to get out into the field more as Schatz did and take more soil samples.  The Streptomyces are slow growing as compared to other bacteria and the production of secondary metabolites can be influenced heavily by growth media.  The plan is to start with selective or semi-selective growth media in the hopes of minimizing the unwated growth of gram negative bacteria, yeasts, and ascomycete fungi (molds).  Once Streptomyces are isolated, they will be subcultured onto different media like Soya Flour Mannitol, Tryptic Soy Agar, and Starch Casein Agar.   I have propionic acid and nalidixic acid to help with selection.

Actinomycetes Isolation Agar w/ Glycerol

Sodium Caseinate ……………..……………………………….2.0 g

Asparagine…..………..………..………..………………………0.1 g

Sodium Propionate…..………..………..………..………..….4.0 g

Dipotassium Phosphate………..………..………..………....0.5 g

Magnesium Sulfate …………..………..………..………..…..0.1 g

Ferrous Sulfate …………………………………………………..1.0 mg

Agar…..………..…………………………………………………15.0 g


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The pictures from a few weeks ago were of Streptomyces coelicolor and Streptomyces avermitilis on both PDA and NA (potato dextrose agar and nutrient agar, as those were the only plates I had ready that day).  I re-streaked them because I was going to do some inhibition testing but instead found myself taking pictures of their beautiful pigmentation and enjoying the smell of geosmin.

I did end up using a spare plate of the coeliclor for a small streak test against Staph.  The interesting thing you might note is the color change to a more reddish hue, which is due to a decrease in the pH of the local medium probably due to waste/metabolites.  The blue colored actinorhodin is interesting to read about, and pretty to look at!

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I’m also quite excited because the brand new UPLC-MS should be online within 2 weeks which will send natural product discovery as well as synthesis verification into light-speed.  I also spent $500 of my own money to finally get an iGEM kit, and am laying the seeds for the first iGEM team at SSU before I leave to grad school next year.  Lots of cool new things to do some hardcore science with!


by Dakota

Santa brings some chemicals and a brand new UPLC-Q-TOF-MS

November 27, 2014 in Posts by Dakota

1029141051With the arrival of some grant money, and the help of Waters, a brand new top of the line MS has been added to the laboratory.  Once fully setup in the next couple of weeks, it will drastically improve the natural product discovery capabilities of the department, and will serve as a fantastic learning tool for many students.   I am interested in how well their databases will be able to identify unknown compounds and how useful the machine will be in the dereplication of NP’s.


I re-plated some Streptomyces coelicolor M145 and Streptomyces avermitilis for use in some future testing, and I’d like some practice in making spore stocks.

You can see the beginning of actinorhodin production in coelicolor to the right, though spore formation has not yet taken place as in avermitilis which is the brown pigment producer.



1125141428The butenolide reaction has been reaching completion at around one hour with the disappearance of the acylated Meldrum’s acid as well as the protected dihydroxyacetone, and formation of the blue butenolide from condensation of the esterification product.

I tried a soil dilution plating while bored one day, and a lot of fungi was on there.  I need to remake plates with propionic acid and nalidixic acid to inhibit fungi/molds and gram negative bacteria, favoring the isolation of gram positive actinomycetes.

Pretty boring post but some cool pictures.  Saw the mansions in Newport, RI and that was both depressing and motivational.  Separation of my last protection reaction was pretty bad, to much DMF left over.  I made an improvement on the protection reaction by switching to DCM and using a different catalyst, so no more dealing with large volumes of DMF on columns.   The bottom spot was my product.


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by Dakota

Driving around in a van with a LCMS

September 21, 2014 in Posts by Dakota

So I’ve either completely lost my mind or I’ve finally caught a break.  I managed to grab a full LCMS (single quadrupole) system complete with high vacuum pumps and software from some very kind people who believe in me.  Although getting a 400 volt direct line in my parent’s basement won’t be possible, at least I can say I have an LCMS in my home lab, which is cool.  My aunts minivan was cruising through the streets with about 1,000+ lbs of analytical chemistry equipment the other day, which put the breaks to the test.

This isn’t a machine I can run from a home-lab anyway as it requires huge power loads and a steady delivery of nitrogen and helium tanks.  I’m hoping I can find a new home for it and or myself soon! .


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by Dakota

Scale up week: GRAMS ON GRAMS

September 10, 2014 in Projects by Dakota

Going to be a short post as I’ve been pretty busy in the lab, even sleeping there a few nights so I can wake up and get to it the next day.  I just think of it as practice for graduate school!

Scaled up the acylation reaction and recovered 21g of product which was ~62% yield.  I would have liked it to be a bit higher but I wasn’t using nitrogen and ended up seeing a portion of my acyl halide disappear into HCl fumes due to water vapor.  I really need to get a Schlenk line setup.

I also scaled up the TBS protection reaction but unfortunately was limited by the remaining imidazole catalyst.

I ran the largest flash column I’ve ever run by hand and it was an experience…definitely an art form I’d say which I’m a long way from mastering.  Collecting fractions by hand while trying to keep the solvent level topped off and making sure the column doesn’t explode is something you must balance delicately.

Sadly, a lot of the early fractions had the product I wanted in them (the lowest dot on the TLC plates) alongside the two unwanted side products (2 dots up top).  I managed to snag a bunch more “pure” fractions which I didn’t end up showing, but you can see the final pooled fraction plate on the right.  I still kept the mixed product fractions as a crude testing batch, but it also looks like the “pure” fractions which have what I want have some imidazole catalyst left over, which is causing streaking.  I’ve heard getting rid of imidazole can be a pain, so maybe next time I”ll do more water washes, or throw in some LiCl2 which I think said can remove it more effectively.

While I was waiting I recrystalized some more Meldrum’s acid from a yellowish mess into nice white crystals!

As for the large purple RBF, I’ve read and was told by some people smarter than me that DMAP ( can be a product of pyridine catalyzed reactions, even though in some cases it’s actually added as the catalyst.  In my case, I only used pyridine, but I assume because it was in DCM, and with some HCl from acyl halide reacting with residual water…that perhaps it was somehow being formed?

NMR spectra look good, but pictures of them are kind of hard to read from a digital image so I’m not even going to bother posting until maybe the end.

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by Dakota

Waka-Flaka-Flame would be proud…going hard in the lab

July 28, 2014 in Posts by Dakota

So the past two weeks have been pretty hectic, as I try to assemble some teaching labs for some basic biotech skills such as transformations and PCR, while simultaneously trying to attempt the multi-step synthesis of the first synthetic target for downstream biological testing.   Waiting on chemical suppliers can be slow, but the arrival of our reducing agent and alcohol protecting group means we can move forward with the entire synthesis.  Couple that with the arrival of the high pressure nitrogen tank for the 300Mhz NMR tomorrow, and things for once seem to be going ok in life.





You can see the successful transformation of DH5a super comp cells from NEB with pGREEN.  The control plate is in the middle, surrounded by smaller LB-Amp plates with pGREEN+ transformants plated out at varying times of outgrowth.   After addition of the SOC outgrowth media, I immediately plated 20uL of the cell suspension, and in other cases I let the cells sit in the media at 37C for 30 minutes, and 1 hour respectively, and plated 20uL.  There did not seem to be any difference in transformation efficiency between the time points (though I know it’s impossible to tell transformation efficiency from those lawns).  I didn’t bother with serial dilutions because I wasn’t concerned with transformation efficiency with pGREEN.

While I was waiting for everything I also brushed up on some gram staining skills, staining  Staphylococcus aureus (little circle shaped bacteria) and E. Coli (the rod shaped bacteria).  








Since Meldrum’s acid is an important reagent in the first step of the synthesis, it’s important to use as pure a product as can be reasonably obtained to insure high yielding 5′ acylation.  As you can see from the picture on the left, shipped from Sigma it is granular with what looks like yellow/orange impurities.  After dissolving in the minimum amount of hot acetone and allowing to cool, followed by an ice bath, nice long needle-like crystals start to form.  The crystals are recovered via vacuum filtration and you’ll notice the comparable difference between the nice white crystals recovered and the residual yellow/orange waste sitting in the filtrate of acetone.


I managed to have a nice skype conversation with some prestigious scientists from the John Innes Center in the UK, so if this all fails, I guess it’s time for grad school.  But, I’m staying positive, even though I’m poor  right now.





by Dakota

Pyridine catalyzed acylation of Meldrum’s acid en route to a β-keto ester

July 21, 2014 in Posts by Dakota

We’re attempting our first multi-step synthesis and have finally gotten off the chalkboard, out of the notebook, and into the lab.   We’re starting with a small 500mg pilot reaction to make sure everything is in working order before we scale up.  As all of the reagents are being paid for out of pocket, mistakes and wasted reagents can become costly!

Acylation is a standard orgo 1 or 2 lab experiment,  but doing something on paper is different than in a round bottom flask.  The arrival of our acyl halide made moving forward with the (hopefully) 5′ acylation of Meldrum’s acid a possibility.  Not wanting to dump our entire 25g ($40) of Meldrum’s acid in a RBF and go with the literature procedure, we decided to try it out ourselves on a small scale.


We started with 500mg of the recrystalized (from acetone) Meldrum’s acid dissolved in 2mL of DCM which had previously been dried over sodium sulfate.  We followed that with 4 eq of pyridine which were added in 200uL batches over a period of about 10 minutes.  Since everything was done on such a small scale, we did not use addition funnels, as adding 700uL of a reagent over 10 minutes would be futile using large glassware.  Instead, we opted for small additions using a p1000 micro pipette, which seemed to work ok.

Our Schlenk line was not setup, and the nitrogen gas wasn’t delivered on time, so we weren’t able to run the reaction under nitrogen like we wanted to.  While not absolutely necessary, it could theoretically improve yields by keeping moister out of the reaction container, which would quickly eat up our acyl halide.

An equimolar equivalence of our acyl halide was added to the reaction after being diluted 4x in dry DCM.  Upon addition of the first small batch of acyl halide, the reaction turns yellowish orange as expected.   Small partitions of 200uL of the acyl halide in DCM are slowly added to the reaction mixture over a period of about 45 minutes, and the solution starts to turn darker orange, then deep red/purple.





After the acyl halide was completely added, the reaction mixture stirred for another 30 minutes on ice, then was removed from the ice bath and allowed to stir at room temperature for another 30 minutes.  The reaction mixture was then quenched with 20mL of 2N HCl and the organic layer was removed in a sep funnel.  The aqueous layer was extracted 2x with DCM and the organic layer and DCM extracts were combined.  The combined organic layers were washed with 2N HCl and then with saturated NaCl solution.

They were dried over anhydrous sodium sulfate to yield an orange solution, and excess solvent was removed by rotary evaporation to yield a deep red/orange oil.



TLC was done throughout the reaction, though trying to take pictures of them under UV light was kind of a pain.  We’ll need to develop them with iodine in the future, especially since the acyl halide might not be visible  with just UV as any unreacted acyl halide will probably convert to the carboxylic acid upon touching the silica or just atmospheric moisture.  Hopefully when the NMR is up and running we can make use of though.  I’d like to trust the FTIR we have but…I’m unsure of how accurate it is.



The big dot all the way to the left is the Meldrum’s acid standard.  The 2nd column is half way through the reaction with 0.5eq Acyl halide added, you can see a dot slightly above the Meldrum’s acid and then a dot town towards the bottom.  The 3rd column is the final extracted and rotovapped product.   Since we’re adding a pretty decent sized alkyl chain, I was thinking the product would be more soluble in the mobile phase, and give a higher spot on the TLC.  You can maybe see that the large dot in the final column is indeed higher than the Meldrum’s acid standard…but I’m not that comfortable in determining the success of the reaction via TLC.  I’ll be happy with a decent NMR, though I’d really like to just be able to fly it in an LCMS.

A lot learned and a lot to learn, I’ll try to make picture quality and video quality better in the future, but I was just in a hurry to get going as I’m sick of waiting around for things.  Take action every day!

by Dakota

Recrystalization of Meldrum’s acid from acetone – Prepping for the pilot reaction

July 10, 2014 in Posts, Projects by Dakota

So the reagents for the synthesis are finally almost all here, last one should arrive today.  While we’ve been waiting for things to arrive we’ve been trying to get the NMR at school back up and running.  A lack of nitrogen for the high pressure tank kept me from running any samples today though sadly, so will have to wait until next Tuesday to see how well it works when the gas is delivered.  It’s sad to see such a nice machine (Varian 300mhz) sit in a dark back room so we’re trying to give it a purpose to come back to life!











From a granular yellow/white powder to pretty nice crystals, the first pass will be enough to test the next step which is acylation of the Meldrum’s acid with an acyl halide.  The conditions call for slow addition of pyridine to the Meldrum’s acid and acyl halide in DCM under inert conditions.  We’ll see how that goes…


by Dakota

Streptomyces avermitilis and Streptomyces coelicolor

June 23, 2014 in Posts by Dakota


Just a quick update that our donated strain samples are growing!  We don’t have an incubator so we’re making due with a room temperature dark cabinet, so while not optimal, it gets the job done.

We plated our samples of Streptomyces coelicolor and Streptomyecs avermitilis about a week ago, and it seems they have finally undergone formation of aeriel hyphae alongside production of the pigmented polyketide antibiotic actinorhodin (in the case of coelicolor).    One of the plates of coelicolor does not look the same as the other colonies though.  A purple color is being produced by the organism, and they have a much smoother/slimier look to the colonies.  Perhaps they are a day or two away of forming the fuzzy aeriel mycelia, or perhaps they are a mutant.   We will keep an eye on them.

We will be using them in our future work as part of a bio-assay for the compounds we are making.  The one picture of the brown pigment diffusing from the two colonies are those of S. avermitilis, the maker of avermectin.



by Dakota

DNA Barcoding of fungal endophytes followed by DNA sequencing

June 20, 2014 in Endophytes, Posts by Dakota

So while we’re waiting for some reagents to come in for the synthesis of our first chemical product, I’ve been helping to run a class on the natural products of fungal endophytes.  Most of the work we’ve been doing the past few years on our own has been surrounding bio-active secondary metabolites originating from fungal endophytes, inspired mainly by the work of Dr. Gary Strobel of Montana State University.   One of our professors liked the idea enough to actually make it the main focus of one of her courses.  In exchange for our help and the use of some of our equipment, we get access to a University lab space and the associated perks that come with that, like consumables and access to machines we could never afford on our own like a UPLC, NMR, GC-MS and soon an LCMS.

It’s been rewarding, but also stressful at times, as trying to do molecular biology and microbiology in a chemistry lab is…difficult.  We’ve basically had to buy or borrow all the necessary equipment, and sometimes had to get creative.

Nevertheless, with a few setbacks like our -20C freezer failing and ruining all our reagents, we’ve been able to push forward to obtain some sequence data from the ITS (internal transcribed spacer) region of a few isolates the students have made.

The gel above is from students using a quick lysis method which entails a toothpick tip full of mycelia in water followed by incubation at 95C for 3 minutes, then ice until ready for use. The ladder used is a 1kb ladder from NEB. The first two lanes are +controls comparing previous DNA preps of a basidiomycete, followed by student samples.

Only three PCR products were observed on the gel, one being quite faint, in addition to the two controls.  The student who prepped the reaction in lane 7 and 8 seemed to have forgotten template DNA while overloading primer, and forgetting it in the 8th tube…which potentially explains the extremely bright primer cloud and absence of it in lane 8.

Nevertheless, we were still able to get some decent reads and contigs out of the data.

For the band in well 5 – it was a white filamentous ascomycete isolated from garlic.

The contig is as follows if one would like to nucleotide BLAST it.


It appears to be from Fusarium Proliferatum which, upon a quick morphological check and Google, seems to check out.  I guess that particular species is present as a plant pathogen in garlic bulbs according to google.  With few mycologists around, it’s been hard to positively ID via morphology many of the species.  I can only pick out with confidence Penicillium and Aspergillus species.  I have a better picture on my phone of the spores, but they look like long stretched out footballs and seem to match the spore shape of many fusarium.

95C 3 min initial denature

95C 30s denatration

52C 45s annealing

72C 1 min elongation

Repeat 34x

72C 5 min final elongation

1 uL crude template

2uL ITS1 / ITS4 10uM primer master mix

12.5 uL 2x  Taq NEB Master Mix

9.5 uL water


5uL PCR rxn load onto a 1% agarose gel stained with GelGreen

The other contigs follow below.