phytochemical studies:

Plants for medicines, CSIRO, 1990

There is a reference in this book to a. obtusifolia found to contain 0.15% alkaloids in the bark. The specimen cited is from Springbrook Qld, and there are no further references to any papers with more information, and no qualitative analysis. This work is a collection of results from hundreds of tests that were part of a post war phytochemical study of the Aust flora.

Authors studies 1994-6

I was introduced to the alkaloids of a local acacia in about the middle of 1994. I was told that the brown crystally stuff was extracted from the bark of a. maidenii, a species common to some areas not to far from home. I was quite interested to learn more about these plants and their alkaloids. I spent some time bushwalking and found some a. maidenii, lots of them in fact. I was quite sure that I had identified it correctly, though I decided that I should talk with the person who had first given me some of the alkaloidal extract, before trying an extraction on the bark. Along with this I had spent some time looking up journals and books to see what else I could find out.
I talked with my friend and told them that I had found a. maidenii but that I would like to see if they were the same as the acacias used previously. I went to the site they had used and to my surprise found that there were no acacias I could identify as a. maidenii in the area. There were however a lot of another type of acacia there, it was early jan 1995 and they were flowering, I identified them as a. obtusifolia, another relatively common species from the area.
I talked again with my friend and in Feb we both went to both sites, the one they had used previously, and the site where I had found what I believed to be a. maidenii, collected specimens from both sites and took them to a qualified botanist for identification, They identified them as a. obtusifolia and a. maidenii respectively. So it seems that a. obtusifolia had in this case been misidentified, my friend was under the impression that it was a. maidenii, it had however been found to yield entheogenic alkaloids for at least a year prior to this point.
We also collected some bark from both sites, my friend took them and did an extraction on equal amounts of the bark, I was not present, and found that the a. obtusifolia bark yielded about five times the alkaloids of the a. maidenii bark, which yielded only a tiny amount anyway. We had heard that other people had used bark from trees they identified as a. maidenii but had given up due to the low yield not really making it worth the effort. See further stuff regarding this under a. maidenii.
On subsequent bushwalks I looked for and collected bark from a. obtusifolia from a different site to both previous sites. I then tried to extract the alkaloids from the bark, with varying results, though after some practice was able to obtain a creamy crystalline extract that smelt strong and distinctive, melted at a low temperature and would produce an astounding though relatively short lived entheogenic experience if a small piece is smoked. The same effect as the other extract that I had obtained from my friend.
I know of other people who have now also been able to obtain similar results from this same species now that it has become a little known about, though I don’t think very many people are aware of this. Over the last year awareness of tryptamine alkaloids has grown and many people have now tried them, and as far as I know a. obtusifolia has been the most common source plant, even though there are no qualitative analysis of these alkaloids.
The physical properties and effects as far as I can gauge, suggest that they are tryptamine alkaloids to me, especially DMT. A very intense, colourful visual, sometimes out of body entheogenic experience that lasts for 20-30 mins if smoked, 45 mins later and you feel like you haven’t had anything!
DMT has been found in other members of section Juliflorae, namely a.maidenii and a. phlebophylla. Most people are astounded by the experience, with some being a bit shaken and unsure afterwards, it sometimes taking quite a bit to integrate the experience with other experiences.
I have made collections at different times of the year and haven’t really noticed a great change in the alkaloid content over time, or in different locations that i can put down to anything specifically, though I have only in more recent times actually weighed the bark and alkaloids. When I have done this it has generally been from 0.4 to 0.5 % alkaloids in the dried bark, though is quite variable. Another factor has been the improvement in the extraction process, including grinding the bark finer. I am now able to obtain the alkaloids as creamy golden crystals, that do seem to darken a bit if left exposed to the air or heated, there does seem to be a small amount of a yellow oily matter present to varying degrees sometimes. I would say that there is some sort of mix of alkaloids as there seem to be at least two crystal types, the minor one growing into fine tree like clusters, the more common is larger sugar crystal size forming on the bottom of the container, sometimes together in circular forms or even free double terminated crystals.
One time some fresh plant tops were collected, and an extraction done on them, and found that they yielded an alkaloidal fraction, a yield of about 0.07% of the fresh (undried) weight in this case. From the smell, size, shape of the crystals and other similarities I would say that the alkaloids are quite similar to those from the bark.
I and a few others have now also found that the alkaloids can be used in combination with b-carbolines (syrian rue seeds) to produce an ‘ayahuasca’ analogue. 3 to 5 gms of syrian rue seeds plus at least 2, up to 4, ‘smoking’ doses of the alkaloids. For me 3.5 gms of syrian rue seeds and about 2.5 times what I considered a ‘smoking’ dose of the alkaloids produced a strong effect, first felt about 15 min after finishing ingesting a cup, which I drank over about 1/2 to 3/4 of an hour. Building up and peaking over an hour, still strong but diminishing effects for next 2-3 hrs. Amazing closed eye visual..(-:..... auditory tones, buzz’s and pops, intense body sensations and visualisations...(-:.. some relaxation due to b-carbolines... :-). No apparent physical after effects, I felt excellent, an amazing journey which is much how it felt.
I went to Mt Buffalo and checked out a.phlebophylla and found that this species seems to have many similarities to a. obtusifolia, leathery dull green phyllodes with red granular margins, and especially the very young growth is very similar. All the a. obtusifolia seem to produce the same legumes however, which are quite distinctive from a. phlebophylla. Some times I have seen other specimens produce large broad phyllodes in certain conditions, eg plants that have had there above ground parts killed by fire I have seen growing back from underground shoots, the phyllodes on these shoots sometimes seem to be particularly broad. Obviously both genes and enviroment combine to produce different local and not so local types. Cross breeding and hybridisation between species is also a possibility where distributions of closely related species overlap.
The new growth or tips of both these species when ‘toasted’ with a heat source give of a strong and distinctive smell, due to the alkaloids. It seems that there is quite a concentration of alkaloids here. This new growth when dry, becomes almost black and can be easily finely powdered as it seems to have very little fibre. I put about a teaspoon of this powdered dried tips in a clay pipe and along with a friend smoked it. It was relatively hard work to smoke, a bit like a bushfire, but a distinctive smell and sensation due to the alkaloids could be felt. By the end of it my mouth was very numbed due to the alkaloids, though the effects were not particularly strong in terms of visuals or anything, and it would seem pretty dificult to get a strong effect from this. A mild pleasant buzz would be an apt description. MAO inhibition might potentiate this however. The alkaloid content of this young foliage seems relatively high, at least compared to mature phyllodes.

Taxonomy and related phytochemical studies

Acacia obtusifolia was formerly known as a. intertexta, and it was a species identified as a. intertexta that was first found to contain the flavanoid teracacidin in it’s heartwood. The species used was later identified as a separate species, namely Acacia orites, in 1964 (L Pedley, Proc. R. Soc. Qld, #75:29) and a. intertexta became a. obtusifolia. It seems that the recording of 0.15% alkaloid content for the bark in previous references was actually from a species identified as a. intertexta. I don’t know if this is the same specimen that was later identified as a. orites though, as I have been unable to find any papers that mention any alkaloidal component, apart from the ones mentioned before and below, which gives no further references for that specific finding.
Subsequent tests found one specimen identified as a. obtusifolia to also contain teracacidin (from Qld), with another found to contain also melacacidin (from NSW), another related flavanoid found in other members of mainly sections Juliflorae and Plurinerves. Teracacidin was also isolated from a. maidenii and a. auriculiformis heartwoods, this group forming a sub group within section Juliflorae. Recently a. auriculiformis phyllodes have tested positive for alkaloids and it’s traditional medicinal uses by Aboriginal people in Nth Aust documented.
I found some a. orites and could understand how there may have been some confusion with a. obtusifolia, especially in some specimens whose phyllode colour and texture is very similar to a. obtusifolia, and the phyllodes being quite erect in a similar fashion. Acacia orites (nightcap wattle) has a very restricted distribution, especially in comparison to a. obtusifolia, it being found only around the Nightcap national park and ajoining forests in NE NSW, and isolated occurences in Qld just a few kms to the north. Apart from the phyllodes it is however a quite different plant to a. obtusifolia, growing into large trees, >35 m high, in subtropical rainforests and margins, a single main stem carrying the crown high into the forest. It has been logged for it’s timber it grows so big.
Previously I collected a small quantity of bark from this species to see if it had any alkaloids, and I found that it was inconclusive, only obtaining a minor amount of a brown gummy matter with a slight alkaloidal taste and smell. More recently I tried an extraction on the bark of this species again, with a slightly more workable amount, but found that there was a negligible alkaloid content again, hardly enough worth registering, similar to results I have had with a. maidenii bark.


Clarke-lewis & Dainis, Flavan derivatives in a. obtusifolia & a. maidenii, Aust J Chem #20:2191-8, 1967.
Tindale & Roux, Phytochemical survey of Aust acacias, Phytochemistry #8:1713-27, 1969.
Tindale & Roux, Extended phytochemical survey of Aust acacias, Phytochemistry #13:829-39, 1973. Plants for medicines, CSIRO 1990