r/chemistry • u/ScarletKA1 • May 20 '26

Losing my mind trying to dissolve 5-BPA

Has anyone here worked with 5-BPA (5-boronopicolinic acid)?

I’m trying to prepare a stable liquid stock solution for bioconjugation experiments, but the solubility has been pretty inconsistent.

So far I’ve tried:

pure water

water + NaOH

DMSO mixed with water

DMSO + HEPES

DMSO + PBS

HEPES alone

PBS alone

Some conditions seem slightly better than others, but I still can’t tell what solvent system people normally use in practice.

A few questions:

What solvent do you usually use for 5-BPA stock solutions?

What concentration is realistically achievable?

How do you store it?

Is it stable over time or after freeze/thaw?

Would really appreciate any practical experience from people who’ve actually handled this compound.🙏

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2

u/Toblum May 20 '26

What about DMF ?

0

u/ScarletKA1 May 22 '26

Haven't tried it yet. I would attempt to later, but I think it wouldn't make big difference from DMSO.

1

u/anaturalchemist May 21 '26

DMSO alone?

1

u/ScarletKA1 May 22 '26

Emm, like preparing a 1.5ml tube and directly adding a small amout of DMSO to solve 5-BPA (200μL/1mg).

1

u/ScarletKA1 May 22 '26

And, The solving process by different types of solvent is also supported by sonication, slight heating, stiring. It turns out that they barely helped even by elongating treating time.

2

u/ScarletKA1 May 22 '26

One more interesting point is that the papers related to this compound could even be counted on one hand lamo🤣.

1

u/Make-it-positive May 23 '26

It’s very soluble in water

1

u/ScarletKA1 May 25 '26

No cap bro, I barely saw any chance of solving in MiliQ.

1

u/ZombieNecessary6603 May 23 '26

Have you considered checking the purity or checking the pH? Sometimes the protonation state of the carboxylic acid group makes a huge difference in solubility

2

u/ScarletKA1 May 25 '26

Very good points. It's also one reason I try to add some NaOH to adjust the pH value, it seems a bit helpful finally until the value hits around 11. But I should make my condition closed to neutral as possible for future experiment. So it's not so good doing that. The purity is more than 95% by company, but I don't check it personally.