Manuel Aregullin

Prospecting for Botanical Gold

Dr. Manuel Aregullin

Dr. Aregullin’s workstation.

Far More Than a Drawing Application

According to Dr. Aregullin, ChemDraw has evolved over the years from a dedicated drawing application to one with far more sophistication. For instance, he can use it to make NMR or mass spectrometry predictions. Because his research relies heavily on the use of mass spectrometry (particularly electrospray ionization mass spectrometry) and NMR analyses, he finds this feature to be one he uses quite often. The latest version, ChemDraw Ultra 10.0, facilitates more accurate chemical shifts and splitting patterns for proton NMR spectra and displays the predicted spectra more clearly for both proton and carbon-13 NMR predictions.

“ChemDraw Ultra for Mac OS X is very robust,” says Dr. Aregullin. “The software lets you just draw a structure and ask for either a theoretical NMR spectrum or the theoretical mass spectrometry fragmentation. With the cursor, you can actually just draw lines where you want the molecule to fragment and it automatically gives you the fragments that are formed within the respective masses. Let’s say I’m looking at an experimental mass spectrum with peaks corresponding to fragments of various masses, and on ChemDraw I have, let’s say, a hypothetical structure. I can quickly just fragment the molecule with the cursor using the fragmentation tool and see if any of the theoretical masses correspond to any of the peaks that I see in the experimental spectrum.”

“It is a tremendous advantage that the Mac can read PC-generated files, such as PowerPoint presentations, with all the convenience of only having to use one computer without missing a step.”

TLC Fading No Longer a Problem

Another ChemDraw feature Dr. Aregullin finds particularly helpful is the thin layer chromatography (TLC) plate drawing tool, which assists in depicting TLC results within a ChemDraw document. Because of the nature of TLC, the test results normally fade within hours. One could take a picture of the plate, but it isn’t always reliable because of variations in photographic quality. With the TLC drawing tool, this alleviates the problem of TLC record-keeping. “In the past there was no simple way to archive the results in thin layer chromatography because the plates cannot be kept for a long time, a few hours and that’s it,” Dr. Aregullin explains.

He also has occasion to use ChemDraw to assist with retrosynthetic analysis, in which he has to synthesize a promising chemical he’s isolated from a larger compound. “Every so often, as a matter of fact right now, I have a chemical that I believe is new that I have isolated from yeast,” he says. “I have the mass spectrometry information and I have proposed a structure. But now I have to prove absolutely that that’s what I have. And so I’m going to have to synthesize it. So in those instances in which one tries to come up with a critical synthetic route, the retrosynthetic analysis is very useful.”

ChemDraw in the Lecture Hall

In the classroom, Dr. Aregullin presents his lectures with a 15-inch PowerBook G4 and an Epson LCD projector and screen. Though most of his instructional materials are prepared in advance, when he needs to draw molecules on the fly as he lectures, he can do so with ChemDraw on his PowerBook.

His PowerBook also serves as an in-class resource for student presentations — even for those created on the PC platform. “My students are required to give an oral presentation on a topic related to the course,” Dr Aregullin explains. “It is a tremendous advantage that the Mac can read PC-generated files, such as PowerPoint presentations, with all the convenience of only having to use one computer without missing a step.”

Keynote and PowerPoint Interoperability

An important part of Dr. Aregullin’s work is presenting results to others in a group setting and in distribution of reports. To help with this, he uses Keynote, Apple’s presentation application.

Keynote allows him to easily import ChemDraw data into his slides. It also provides an important feature that comes in handy when distributing presentations to users of Windows products. “I can generate a presentation with Keynote, and then if I want to, I can save it in a PowerPoint format,” he says. “If you go and give a talk somewhere else, unless you carry your computer and software and all that stuff, you cannot just take your flash drive with a file, because if they don’t have Keynote then you’re out of luck. But you can save Keynote files as PowerPoint files and benefit from all the Keynote templates that in many cases are more useful to me than what I get with PowerPoint.”

Whether in the classroom or in the research lab, Dr. Aregullin has grown to depend on Macs for their reliability, consistency, and the ease of finding solutions to his work-related problems. “I know the operating system so well, and that is because I’ve used it for the last 20 years,” he says. “Also, it’s so intuitive, while PCs are so cryptic to me. Who knows where PCs hide things, while Mac OS X doesn’t hide anything. Everything is in plain view.”

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So Many Prospects, So Little Time

The promising chemicals that Dr. Aregullin and his students discover are important to pharmaceutical companies, who then test the efficacy of these substances against drug targets implicated for various diseases.

But Dr. Aregullin’s work is hampered by extinction of plant species due to decimation of habitats and the fact that native cultures worldwide are disappearing or being assimilated into mainstream society. Further complicating the scientific prospecting efforts are concerns about intellectual property rights to any information gleaned from indigenous groups. This has made access to areas ripe for scientific discovery quite a bit more difficult, including the Amazon basin.

Another promising way of prospecting for medicinal plants is to observe animal behavior. Dr. Aregullin is investigating how certain animals use plants when they are ill, a relatively rare field of study called zoopharmacognosy. He explains that sick chimpanzees and gorillas have been observed by anthropologists to ingest particular groups of plants that they wouldn’t eat at any other time. “There have been many anecdotal accounts of animals using plants and plant products for a purported medicinal benefit, especially in Africa,” he says. “Those have been put in the category of animal medicinal plants. And through the years, I have looked at the chemistry and evaluated the pharmacological potential of some of them. There are other groups that have done the same, but there aren’t that many in the world doing this type of thing.”

But as plants, animal habitats, and native cultures disappear worldwide, the time for discovery is short, and the clock is ticking — “at a very rapid rate,” says Dr. Aregullin.