Salvinorin A was notsoluble in 100% propylene glycol to our surprise. However,solubility increased in propylene glycol by adding increasingconcentrations of DMSO. A 9:1 mixture ended up beingsuitable for our studies
I'm quite a novice in chemistry. I assume a 9:1 ratio would work with other solvents replacing the 9 parts propylene glycol. That is to say, given that salvinorin A was not soluble in propylene glycol, I'm assuming the propylene glycol plays little to no role.
Exceptionally, chlorophyll b was not found in any of the top phases. The lack of chlorophyll a and chlorophyll b in some ATPSs could be due to low extraction efficiencies or a change in the molecule structure by oxidation. Chlorophyll stability is affected by temperature, light irradiance, acids, bases and oxygen, causing the loss of its magnesium ion and/or phytol group40 and a change in colour to olive‐brown.41
Which one it is should be possible to determine by running multiple washes and visually assess how much pigmentation is removed. The idea is to dissolve acetone plant extract, add PEG-400, let the acetone evaporate, pour PEG-400 leaving sediment and/or crystals, then repeat. While I'd probably be doing this with salvia divinorum, any leaf should work for testing chlorophyll washing.
Chlorophyll a was recovered by PEG400‐Ch DHp (50.6 ± 2.3%), but it was not detected in the other two systems at 660 nm [Fig. 2(b)].
They seem to be saying that PEG dissolved 50% of the chlorophyll? I also don't know what what Ch or DHp means. I'm somewhat outside my wheelhouse.
Assuming PEG-400 does not dissolve salvinorin A, then it may be an excellent option for purification of salvinorin A.
SA was soluble in 25% dimethyl sulfoxide (DMSO)/75% polyethylene glycol 400 (PEG-400) at 4,000 μg/mL and was stable for 6 days, as determined by LC-MS/MS, with only trace amounts of the hydrolysis product salvinorin B (SB) forming.
As with DMSO and propylene glycol, I suspect that the DMSO is doing the dissolving. Given that it appears to only take 10% DMSO to dissolve salvinorin, naturally the 25% works. Unfortunately, I see no mention of whether salvinorin A is soluble in pure PEG-400. I suspect it is not.
4. Allow acetone to evaporate in a dark, well-ventilated area. You will be left with a bright green powder – about 1g per 100g of leaf. This powder is about 2 parts chlorophyll to 1 part salvinorin A.
This is incredibly useful information.
I noticed my extract had some bitter taste and some earthy notes. I don't know what salvinorin and chlorophyll taste like, but I assume the taste comes from other impurities. However, I extracted for many minutes (10 or so); next time, I should do only the 3 minutes suggested here (3 times 1 minute).