FOR FEBRUARY 2001 ISSUE

THE POISON SLEUTHS

DEATH BY STROPHANTHUS

-Dr. Anil Aggrawal

“Good morning doctor. Oh, my God, what are you doing today? You have the dead body of a young man today. What happened to him? Please tell me.”

“Good morning Tarun. The name of this young man is Radhakant, and he died in the hospital today morning. Yesterday evening he was sitting in his room reading a book, when suddenly he felt a stinging pain in his neck. Quite instinctively he groped his neck, and found a little needle like thing sticking out of the back of his neck. He tried to take it out, but could take out only a part. The rest broke inside his neck. When he examined it, he found it to be a dart, much similar to the one with which children play. He thought that some child had played a prank with him, and gave it no further notice.”

“Was he sitting with his neck to the window?”

“Yes, that’s right. That’s how he was sitting. I must tell you that he lives on the ground floor flat, and the window of his room opens out on the road, when all kinds of person pass about. He actually glanced out of his window immediately after the incident, but could not see anybody around. There were two or three people walking about quite nonchalantly, and he did not think any of them had played that mischief. So he went back to his chair and continued with his book. After some time, he felt some heaviness in his chest. His breathing became labored, and what was most conspicuous to him was that his heart started pounding on his chest very heavily. He also had diarrhea, fatigue and marked muscular weakness. He telephoned his doctor, who advised him to come to his clinic right away. In the clinic, the doctors tried to diagnose the disease, but couldn’t. Today morning he expired. The police has seized his body and has handed it over to me. Radhakant was only 23 years old, and he had no reason to die at such a young age. Obviously there is something black at the bottom, and it is my duty to tell the police how he has died.”

“So what do you make of this death doctor?”

“Tarun. I have studied his symptoms very carefully. I also took into account the fact that he had been shot by a dart. When I conducted the autopsy, the first thing I did was to dissect his neck, and can you imagine what I found?”

“What doctor?”

“Tarun, I found this conical tip, which as you can very well see is almost two cm long and is hollow from the inside. It can hold almost 10 cc of fluid in it. Most of the fluid that was inside it has already diffused into Radhakant’s neck muscles, and presumably caused his death, but some fluid is still remaining inside. I tested it chemically and I found that it was strophanthin.”

“Strophanthin! Never heard of this as a poison. Doctor, why don’t we start from the beginning? I can follow your story much better that way.”

“Sure. Strophanthin is a glucoside that comes from plants of genus Strophanthus.....”

Sorry to interrupt you doctor, but what exactly is a glucoside?”

“Let us first see what a glycoside is. You can visualize a glycoside molecule rather like two children holding hands together, with each child representing an independent molecule. If you visualize them as a boy and a girl, it is still better, as the two molecules are rather different in properties. One is a sugar molecule, such as glucose, fructose, galactose or mannose. The other is generally a non-sugar molecule. It is commonly referred to as an aglycone or a genin. When the two are chemically combined, they give rise to a new molecule known as glycoside. On hydrolysis the two portions of the molecule may be made to separate into the respective sugar and a non-sugar portions. It is rather like separating the hands of the boy and the girl. Glycosides are mostly naturally occurring and include vegetable pigments, tannins and even drugs such as digitalis. Glycosides are generally named according to the non-sugar portion which they yield on hydrolysis. For instance, a glycoside which has a stimulating effect on the heart is known as the cardiac glycoside and a glycoside which yields hydrocyanic acid on hydrolysis is known as a cyanogenetic glycoside. Similarly there are other kinds of glycosides such as Sterol glycosides and so on. When the sugar portion of the glycoside is glucose, it is better known as a glucoside. Since strophanthin releases a glucose molecule on hydrolysis, we call it a glucoside.”

“Good. So you were telling me about the genus Strophanthus.”

“Yes. Most common plants of this genus from which strophanthin comes are Strophanthus Kombé and Strophanthus hispidus. Strophanthus is a genus of ornamental and drug plants in the dogbane family (Apocynaceae), with more than 40 species of woody vines, shrubs, or small trees that are native to tropical Africa and Southeast Asia. The flower petals of some species are drawn out into long threads. The bark and seeds of some vinelike species contain strophanthin about which I told you just now. This poisonous substance has been used as an arrow poison by some aboriginal tribes. Strophanthus has a digitalis like action on the heart (Please see “Death by Digitalis” August 1999, Pp 22-24), and so in low doses can be used as a medicine too. Europeans got acquainted with the plant after botanist Sir John Kirke brushed his teeth one fateful morning. He was particularly interested in the poisonous weapons of the tribes and collected arrows in a bag, where he kept his personal belongings too such as his toothbrush. Presumably some of the strophanthin from the arrows got rubbed off onto his brush. When he brushed his teeth with that poisoned toothbrush that particular morning, he felt a strong heartbeat and concluded it had been because of the arrows! He brought these plants to Europe and was described as a new species by Oliver, of Kew, under the name of S. Kombé. In 1885, Sir Thomas Fraser of Edinburgh University extracted strophanthin from the seeds of this plant, and introduced it into medicine in 1890. He discovered its digitalis like action while studying African arrow poisons. The pharmacological actions are identical with those of digitalis, but more rapid and more transient: when a rapid stimulation of the heart is demanded, strophanthin may be injected intravenously and is to be preferred to digitalis, especially as there is less danger of a cumulative effect. Believed to have greater diuretic power, (i.e. one which can cause loss of water through increased urine formation), it is esteemed of greater value in cases complicated with dropsies. Dropsy, as you must be knowing is a condition in which excessive water accumulates in the body. Although widely used for treating heart problems earlier, now strophanthin has mostly been replaced by more sophisticated medicines.”

“Doctor you said that Strophanthus belongs to Apocynaceae or the dogbane family. Can you tell something more about this family please?”

“Sure. Dogbane family of is a family of flowering plants which belongs to the order Gentianales. It includes more than 150 genera and about 1,000 species of trees, shrubs, woody vines, and herbs, distributed primarily in tropical and subtropical areas of the world. Members of the family have milky, often poisonous juice; smooth-margined leaves; and flowers in clusters (rarely solitary). The fruit may be berrylike or fleshy but usually is a dry pod that splits open at maturity, releasing many winged or tufted seeds. Garden ornamentals belonging to the family include periwinkle (Vinca), White Oleander (Nerium odorum), yellow oleander (Cerbera thevetia), frangipani (Plumeria), Natal plum (Carissa), and crepe jasmine (Tabernaemontana coronaria). Several of these plants are poisonous and of these, I have already talked to you about yellow oleander (please see “Poisoning by yellow kaner” September 1999, Pp 44-46). Arrow poisons are obtained from many plants in the dogbane family.”

“Doctor, please tell me something about the Strophanthus plant.”

“Tarun, the name Strophanthus is derived from the Greek strophe (twisted or turned) and anthos (a flower), thus expressing the chief peculiarity of its appearance, the limb of the corolla being divided into five, long, tail-like segments. It appears as if the flower is twisted and hence the name. Curiously the Greek root strophe occurs in several of our commonly used English words, without us realizing it. It appears in words like “apostrophe” and “catastrophe”.  The word apostrophe has a prefix “apo” meaning “away”. Thus apostrophe literally means “turning away”. You would surely know that it represents a mark where a letter or sound has been omitted or “turned away”. Catastrophe has a prefix “cata” meaning “down”. Thus it literally means “turning down”. The word refers to a disastrous event, which surely can be called a turning down event. In medical parlance too, the Greek root strophe makes its appearance at several places. It is seen in terms like cardianastrophe or cardio-anastrophe, both terms referring to a right-sided heart. It is a heart which has actually “turned away” from its natural position. Enstrophe refers to inversion (or turning away) of any part of the body. Phallanastrophe is an upward twisting of the penis, and strophocephalus refers to a child whose head is distorted or “twisted”.”

“Oh, that is certainly interesting. Are there many varieties of the Strophanthus plant?”

“Tarun, there are twenty-eight recognized species of this genus. These are found in Africa and Asia, extending to China, the East Indies and the Philippines. S. Kombé grows solely in East Africa. Its seeds are also known as Green Strophanthus. Another species is Strophanthus hispidus. Its seeds are known as Brown Strophanthus. Other species are S. glabra, S. Emini, S. courmontii, S. gratus (found in Sierra Leone), and S. Nicholsoni. The seeds are of all strophanthus species are lance-ovoid, flattened and obtusely-edged; from 7 to 20 mm. in length, about 4 mm. in breadth, and about 2 mm. in thickness; externally of a light fawn colour with a distinct greenish tinge, silky lustrous form, a dense coating of flat-lying hairs (S. Kombé) or light to dark brown, nearly smooth, and sparingly hairy (S. hispidus), bearing on one side a ridge running from about the centre to the summit. The taste of these seeds is very bitter. The strophanthins from different species were found to vary somewhat in chemical composition, and they are classified as follows: Strophanthin-K when obtained from S. Kombé, Strophanthin-G (also known as Ouabain) when obtained from S. gratus, Strophanthin-E when obtained from S. Emini, Strophanthin-H when obtained from S. hispidus. Some of these poisons closely resemble those of the genus Acocanthera, which are used for a similar purpose. Ouabaio tree belongs to the genus Acocanthera. Somalis of East Africa prepare their arrow poison from this tree. In 1888 Arnaud isolated ouabain from the roots and bark of the Ouabaio tree. Ouabain, which is identical with g-strophanthin, is unique among the cardiotonic glycosides in the ease with which it can be crystallized. This property led to its being adopted as the standard against which the activity of all other such substances could be measured. African native tribes have put these plants to use widely through the centuries. They obtained a thick liquid from its seeds, containing the poison. They dipped the end of the arrows in it, so they were able to kill an animal with these poisoned arrows. In Gaboon the poison is called inée, onayé, or onage.”

“Do these plants contain other toxic products too?”

“Besides Strophanthin, these plants also contain an alkaloid Inoeine, and fixed oil. Sulphuric acid, diluted with one-fifth of its volume of water, colours the endosperm, and sometimes the cotyledons, dark green which shows the presence of Strophanthin. Strophanthinum is a mixture of glucosides prepared from S. Kombé. It is a whitish, crystalline powder freely soluble in water and giving a green coloration with sulphuric acid. Warmed with dilute acids it is readily hydrolized into Strophanthidin and a sugar. In Germany the seeds of S. hispidus are preferred for making medicine because of their guaranteed purity. This plant when growing alone is in the form of a bush, but is usually found as a woody climber inhabiting the forests between the coasts and the centre of the African continent. It then reaches to the tops of the highest trees, coiling on the ground and hanging in festoons from tree to tree. The stem is several inches in diameter. The flowers are cream coloured, yellow at the base, purple-spotted above. The British, French and Swiss officially favour S. Kombé, while the United States Pharmacopoeia recognizes both. The seeds of all species of the genus possess hairs that have a characteristic, thickened base, somewhat like those of nux vomica seeds.”

“Doctor, you told that the tribes prepare arrow poison from these plants. How do they do that?”

“In preparing the arrow poison, the seeds, deprived of their hairs, are pounded to a pulp. This is not an easy job, because they can be powdered only with great difficulty. To make the task easy,t hey are sometimes bruised in an iron mortar with powdered glass. You would probably remember that almost the same is done with ratti seeds (Please see “Poisoning by Ratti seeds”, September 1997, Pp 43-45). After they are reduced to pulp, the adhesive sap of another plant is added, and the mixture smeared for 6 inches along the point of the arrow. Game wounded by such an arrow is said to be rarely able to move 100 yards, while the flesh can be eaten without bad effect.”

“Doctor, are you sure Radhakant died because of Strophanthin poisoning?”

“Absolutely! I have found concentrated strophanthin in the conical tip that has been recovered from his neck. The dart was most probably fired from a blowgun. Thus we are actually looking for a person, who is adept at blowing darts from a blowgun, and who probably knows about poisonous plants too much. I told these findings to the police, and they swung in action. Among Radhakant’s friends was one named Kamlesh, who was a dart champion during his college days. He has done his honors in Botany. On the face of it, it appeared that he was our man. On detailed enquiry it turned out that both of them were in love with a common girl Sudha. Thus Kamlesh had good motive to eliminate Radhakant. The police have raided his house and have recovered several types of blowguns from his house. On his backyard he had grown several Strophanthus plants. The police had no difficulty recognizing them, as I had given them the exact description. The police even recovered some darts which had strophanthin on their tip. It seems almost certain that it was Kamlesh, who killed Radhakant by this extraordinary method.”

 “That is amazing doctor. Without your clever deduction it would have been impossible to say how Radhakant died and Kamlesh may have gone scot-free. What are you going to tell me next time?”

“Tarun, next time, I would tell you about a very interesting poison – Aspirin.”

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(To protect the identity of the individuals, their names, as well as the various dates of occurrence have been changed)

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(Dr Anil Aggrawal is working as a professor of Forensic Medicine at the Maulana Azad Medical College, New Delhi-110002. His E-mail is dr_anil@hotmail.com, and his website is http://www.fortunecity.com/tattooine/simak/76/default.html. His address for correspondence is S-299 Greater Kailash-1, New Delhi-110048: Phone: 6465460