Pseudaconitine, known also as nepaline, (C₃₆H₄₉NO₁₂) is an alkaloid

Alkaloid

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

 found in high quantities in the root

Root

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

s of Aconitum ferox

Aconitum ferox

Aconitum ferox also known as Aconitum virorum is a species of monkshood, in the family Ranunculaceae. It is also known as the Indian Aconite. Abundant at Sandakphu, which is the highest point of the Darjeeling Hills in the Indian State of West Bengal.A deciduous perennial that grows up to 1.0 metre...

also known as wolfsbane. It is extremely poisonous.

Introduction

Pseudaconitine was discovered in 1878 by Wright and Luff. They isolated a highly toxic alkaloid

Alkaloid

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

 from the roots of the plant Aconitum

Aconitum

Aconitum , known as aconite, monkshood, wolfsbane, leopard's bane, women's bane, Devil's helmet or blue rocket, is a genus of over 250 species of flowering plants belonging to the buttercup family .-Overview:These herbaceous perennial plants are chiefly natives of the mountainous parts of the...

 ferox and called it pseudaconitine. The plant has long been known to botanists and travelers in India under the name "Bikh".

Sources

Pseudaconitine is produced by the plant Aconitum ferox

Aconitum ferox

Aconitum ferox also known as Aconitum virorum is a species of monkshood, in the family Ranunculaceae. It is also known as the Indian Aconite. Abundant at Sandakphu, which is the highest point of the Darjeeling Hills in the Indian State of West Bengal.A deciduous perennial that grows up to 1.0 metre...

, which belongs to the family Ranunculaceae

Ranunculaceae

Ranunculaceae are a family of about 1700 species of flowering plants in about 60 genera, distributed worldwide....

. The plant is found in East Asia, including the Himalayas

Himalayas

The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...

. The poison is in the roots of the plant.

Toxicity and mechanism

Pseudaconitine is a moderate inhibitor

Acetylcholinesterase inhibitor

An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, increasing both the level and duration of action of the neurotransmitter acetylcholine.- Uses :Acetylcholinesterase inhibitors:* Occur naturally as...

 of the enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 acetylcholinesterase

Acetylcholinesterase

"Acetylcholinesterase, also known as AChE or acetylcholine acetylhydrolase, is an enzyme that degrades the neurotransmitter acetylcholine, producing choline and an acetate group. It is mainly found at neuromuscular junctions and cholinergic nervous system, where its activity serves to terminate...

. This enzyme breaks down the neurotransmitter

Neurotransmitter

Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

 acetylcholine

Acetylcholine

The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...

 through hydrolysis

Hydrolysis

Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

. Inhibition of this enzyme causes a constant stimulation of the postsynaptic membrane

Biological membrane

A biological membrane or biomembrane is an enclosing or separatingmembrane that acts as a selective barrier, within or around a cell. It consists of a lipid bilayer with embedded proteins that may constitute close to 50% of membrane content...

 by the neurotransmitter which it cannot cancel. This accumulation of acetylcholine may thus lead to the constant stimulation of the muscles, glands and central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

. Furthermore, it appears the substance in small quantities also causes a tingling effect on the tongue, lips and skin.

Structure and reactivity

Pseudaconitine is a diterpene alkaloid

Alkaloid

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

, with the structural formula C₃₆H₅₁NO₁₂. The crystal

Crystal

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

 melts at 202 °C and is moderately soluble in water, but more so in alcohol. This shows that it is a lipophilic

Lipophilic

Lipophilicity, , refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. These non-polar solvents are themselves lipophilic — the axiom that like dissolves like generally holds true...

 substance. When heated in the dry state, it undergoes pseudaconitine pyrolysis

Pyrolysis

Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible...

 and pyropseudaconitine (C₃₄H₄₇O₁₀N) is formed. This does not have the same tingling effect as pseudaconitine.