What are phytoncides? Plant phytoncides. Phytoncides in the garden: microbe hunters Native phytoncides
– and in many cases a medicine for humans. In general, there are two classes of these substances: volatile and non-excretory (that is, non-volatile). In summer, one deciduous forest produces about two volatile phytoncides within one day.
The term “phytoncide” was introduced by the Soviet researcher B.P. Tokin in 1928 and is used mainly in Russian-language literature.
Phytoncides are especially actively released when plants are damaged. Volatile phytoncides, which include secretions from oak, fir, pine, and eucalyptus, have a beneficial effect at a distance. They are capable of destroying protozoa and some insects in a matter of minutes.
Phytoncides of fir - whooping cough bacillus, pine - Koch's bacillus, birch - the microbe of Staphylococcus aureus. But you should be careful with wild rosemary or wild rosemary - their secretions are poisonous to humans.
The impact of phytoncides is not limited to just killing pathogenic bacteria: they also suppress their reproduction and stimulate the vital activity of microorganisms that are antagonists for pathogenic forms of microbes.
Use of phytoncides
The chemical composition of phytoncides varies, but almost always includes glycosides, terpenoids and tannins. Paradoxically, phytoncides protect against infections in humans and animals much more effectively than plants.The list of plants whose phytoncides are useful for humans can be continued for a very long time: these are sage, mint, sweet clover, wormwood, thistle, horsetail, angelica, yarrow and many others.
Both in traditional and folk medicine, preparations containing phytoncides of garlic, onion, St. John's wort, juniper, bird cherry, thuja and many other plants have been actively used for many years. They successfully fight Trichomonas colpitis, heal purulent wounds, abscesses and trophic ulcers. The use of phytoncides internally is recommended for diseases such as intestinal atony, flatulence, intestinal catarrh, hypertension, bronchial and cardiac asthma, putrefactive bronchitis and many others.
Alcohol solutions and extracts of garlic and onion (allylchep and allilsap) in small quantities have a beneficial effect on the body, increase urination, slow the pulse and increase the strength of heart contractions. They are also used for colds and intestinal disorders.
We grow trees and shrubs mainly for their beauty and tasty fruits. However, these representatives of the flora can improve our health by releasing beneficial phytoncides.
What are phytoncides?
This is a complex of antimicrobial substances contained in plants. It includes terpenoids, alcohols, aldehydes, esters and other compounds that can kill or inhibit the growth and development of other organisms (mainly bacteria and fungi). The phenomenon of plant phytoncidity was discovered by the Soviet scientist Boris Tokin in the 30s of the 20th century. Literally it is translated as “killer plants” (from the Greek “phyton” - plant and the Latin “cido” - I kill). There is a persistent misconception that phytoncides are characteristic of a specific group of plants. They are attributed to coniferous trees and shrubs (primarily common juniper), as well as common myrtle, eucalyptus, rosemary and a number of other deciduous species. In fact, phytoncides are secreted by all plants, since they are one of the factors in their natural immunity. Currently, most scientists call phytoncides the term “volatile phytoorganic emissions of plants” (VPEO).
The main mechanism of action of phytoncides is associated with the formation of ozonides (charged ozone), which can destroy the DNA structures of microorganisms, as a result, the bactericidal activity of air increases at least 2-3 times. There are bactericidal and fungicidal effects (on bacteria and fungi), as well as bacteriostatic and fungistatic effects (when the growth and development of microorganisms slows down).
Not all fresh air is equally beneficial. Volatile organic compounds (VOCs) from plants can have positive and negative effects on human health. Thus, in the summer in a coniferous forest, when the period of maximum phytoncidal activity of trees is observed, high concentrations of volatile phytoncides from pine needles can cause allergies. Low concentrations of volatile phytoncides observed in the forest air in winter have a serious therapeutic effect on patients with cardiovascular diseases.
Staying in an oak forest in the summer months reduces blood pressure in patients with hypertension (by 6-12 mm Hg). In the pine forest at the same time, the blood pressure of the same patients increases (by 15-20 mm Hg). The pressure also increases when inhaling phytoncides of lilac flowers and young poplar leaves.
Phytoncides of birch wart have antispasmodic and bronchodilator effects. Patients' sleep normalizes, irritability decreases, shortness of breath and cough stop or decrease, and their mood improves. But we must remember that volatile phytoncides of pyramidal poplar (in May), linden and lilac flowers, and pine (in summer) are poorly tolerated by patients with asthmatic bronchitis and pneumosclerosis.
In general, during the growing season, 370-420 kg of LFOM are released into the atmosphere from 1 hectare of pine plantings, 320-405 kg of spruce plantings, 190-220 kg of birch plantings, and 170-190 kg of aspen plantings. The highest content of phytoncides is observed in a pine forest, then in plantations of spruce and larch, then in mixed coniferous-deciduous plantings, in birch and oak forests, aspen and maple trees.
Dynamics of phytoncides content
The amount of phytoncides released varies depending on the type of plant, its age, size, condition, soil and climatic conditions of the region, and environmental factors. 
Daily activity
In tree and shrub species, activity peaks around noon. In the morning, their content in the air is lower, for example, in pine and birch forests at this time the amount of phytoncides is 3-4 times lower than in the daytime, but their concentration is even lower in the evening - 7 times lower than during the day.
Seasonality
In most tree and shrub plants, phytoncidity gradually increases from spring, reaching its highest values in summer (June-August), then decreases. The well-known Cossack juniper in spring and summer, during active growth, releases 1.18-1.49 mg%/h, and in winter only 0.53 mg%/h.
Age
Young leaves of birch, other deciduous trees and pine needles produce more volatile substances than mature leaves of a later age. The release of phytoncides is also influenced by weather and some environmental factors. Thus, an increase in ambient temperature to +20...+25 °C almost doubles the concentration of phytoncides.
The flora that surrounds us is the greatest miracle and a generous divine gift, supplying natural phytoncides to protect against the effects of harmful microbes. And not only our physical health, but also the psycho-emotional component depends on how carefully we treat nature. Let's take a little closer look at how, where and when healing phytoncides are formed around us.
Natural phytoncides - form, quality, properties
Quite unnoticed in our world, in addition to plants, animals, insects and other creatures that we distinguish with our eyes, there is also an invisible microcosm, which is hordes of all kinds of bacteria and various microorganisms. And these microorganisms are invisibly nearby, in almost everything that surrounds us.
Even in such a seemingly harmless object as a lump of earth, almost 1.5 million microbes and bacteria live! And this microcosm can be conditionally divided into one that harms others, exists neutrally relative to them, and, finally, one that has a beneficial effect on the entire life activity of the planet. We already talked about the ratio of beneficial and harmful microbes when we considered the concept of using EM technologies in the garden.
Phytoncides and their effect on microorganisms
So, let’s say, “positive” microorganisms tirelessly and constantly cleanse the planet of various rot, unnecessary or diseased tissues. For example, take fallen leaves, which quickly decompose and become part of the same earth. All this happens not without the help of bacteria - it is they who significantly speed up the process of its processing, which frees up space from a mountain of already unnecessary foliage.
But “negative” microorganisms become the causes of all kinds of diseases, and it is necessary to protect ourselves from them. Animals have their own immunity to such microbes, protecting them from disease. What about plants? They also have their own defense system against harmful microorganisms and have, so to speak, antimicrobial properties.
This is expressed in the release by the plant of certain volatile substances into the atmosphere, which are capable of acting at a distance, or by the properties of the plant tissues themselves, where the antimicrobial effect occurs upon direct contact of the plant tissue and the pest. At the same time, plants help not only themselves, but also the entire world around them.
Such “useful” properties of plants have been noticed and used by humans for their own purposes for a very long time. All “greens” exhibit their disinfectant properties differently, and many human professions have used them for their own purposes. For example, plants such as hops, oregano, and wormwood counteract the development of putrefactive microbes, which was used by brewers and cooks. But thyme and tarragon have some preservative properties, which were successfully used by hunters who covered their prey with them.
Such antimicrobial substances secreted by the plant world are called “phytoncides”. Their existence was deduced and proved by the Russian scientist B.P. Tokin, from whom they got their name: “phyto” - plant, “cido” - I kill, a mixture of Greek and Latin.
The release of phytoncides in different plants occurs differently: in aboveground plants - into the air, in underground plants - into the ground, and in aquatic plants, respectively, into a reservoir. And the concentration of released phytoncides can be varied even in the same plants - it depends on the environmental conditions, the quality of the soil, and the state of the crop itself. For example, the fungicidal properties of clematis on rich fertile soils are much higher than on poor ones.
What plants produce phytoncides?
As already mentioned, a plant can secrete phytoncides either as a volatile substance or as damaged plant tissue. By the way, it is not necessarily injured leaves that can release medicinal phytoncides; it is the strength of a healthy leaf. For example, an oak leaf actively and successfully destroys ciliates if they suddenly land on the leaf.
But the strongest enemies of Staphylococcus aureus are bird cherry and linden. Poplar and birch trees are recognized as the fastest in destroying microbes. Therefore, it is not for nothing that forests are called the “lungs” of the globe - they not only release oxygen, but also literally clean the surrounding air, killing all harmful and dangerous microbes. A person, inhaling this air, also cleanses his lungs. After all, every year, thanks to the “greens,” 490 million tons of volatile disinfectants end up in the atmosphere!
It is a mistake to think that only some plants emit phytoncides; in fact, all plants emit volatile phytoorganic secretions, because their appearance is a natural reaction of the immune system. Volatile phytoncides released by plants, trees, and other crops protect the whole world from harmful bacteria and microbes.
They work effectively not only in close proximity, but also at a distance. And their activities can be easily verified using the simplest examples. For example, the most harmless thing is a bouquet of fresh lilies or bird cherry branches. They release their aroma, but if you leave them in a vase indoors, after some time a person will start to have a headache. This is what reveals the effect of phytoncides.
And if finely chopped leaves of the same bird cherry are placed under some kind of impenetrable cap, and a fly is placed there, then you can be sure that after a certain number of hours the insect will be dead, poisoned by phytoncides. The same thing will happen if you place a mouse under a hood - it will be poisoned before it suffocates from lack of air. In general, it is better to scare away rodents with elderberry branches; they really don’t like its smell.
The same natural phytoncides that exist in the tissue, in the sap of the plant, are released upon direct contact with microbes and bacteria. Therefore, the sap of many trees is disinfectant and antimicrobial.
The presence of phytoncides in the world is a salvation, but the number of plants on the planet needs to be monitored, increasing their number - planting new forests, planning plantings, and engaging in urban gardening, which is especially important. The presence of the simplest, most basic colors is also important in the apartments. For example, geranium and begonia reduce the number of harmful microorganisms in an apartment by 43%, and chrysanthemum by as much as 66! But some “overseas” plants are also useful - these include myrtle and eucalyptus.
Plants also have one more important quality - the ability, when exposed to the sun, to release electrons from the surface of the leaf, that is, to ionize the surrounding air. The ionization of air that occurs improves its quality, which means it has a beneficial effect on the general condition of a person. The degree of ionization plays an important role here. After all, for example, it has been proven that the most healing air is mountain air. It is in it that there are about 20,000 negative ions per cm³, while in industrial areas their concentration ranges from 100 to 500 and not thousands, but just pieces!
Forests are the planet’s protective belt from harmful microorganisms
Pine is one of the most famous “phytoncidal” plants, and people have been using it for a very long time. One has only to remember the countless number of sanatoriums, boarding houses, and hospital complexes built in pine forests. By inhaling pine air, a person’s lungs, like his entire body, are, to one degree or another, cleansed of various microbes. And the risk of catching a cold practically disappears. Coniferous forest releases about 5 kg of volatile phytoncides per day.
Juniper is also a fairly strong disinfectant plant, and in terms of the amount of phytoncides it produces, it probably takes first place. Juniper forests become a source of about 30 kg of volatile substances every day. This is about 6 times more than all other conifers. What can we say about deciduous forests, which produce 15 times less phytoncides under comparable conditions? But this plant is too sensitive to the environment - its pollution threshold is exceeded (for example, industrial production in the city), then the juniper simply dies. That is why he is a rare visitor near cities.
The deciduous forest releases 2 kg of healing phytoncides every day. But, despite the fact that, in comparison with coniferous forests, this seems to be not enough, this is far from the case. Deciduous forests also successfully fight microorganisms, purifying the air. For example, in a sterile operating room, the presence of harmless microbes is allowed in an amount of 500 per cubic meter. And in a birch forest, you can count only 450 microbes in one cubic meter. Oak also acts as a powerful orderly for the surrounding world, keeping bacteria and germs away. But maple can not only kill bacteria, but also absorb harmful formations, such as benzene.
All this speaks of the extremely positive impact of forests on the health of the entire planet and humans in particular. That’s why it’s so important to go out into nature – where there are flowering meadows, fields, forests. They will help cleanse and heal the body.
Natural phytoncides that enter the human body through the lung systems, as well as through the skin, have a negative effect on the bacteria located there, inhibit disease processes, kill microbes, inhibit the aging process, and exhibit anti-infective properties.
Phytoncides also have a beneficial effect on the digestive system and normalize blood pressure. But not only. Separately, it is worth noting the positive effect of inhaling phytoncides on the human psyche.
The healing effect of forests on humans can be seen in the following examples - people who live in forest areas have healthier respiratory organs, lungs, and cleaner airways.
In the real world, where technology, industry, and progress come first, man deprives himself of such natural sources of health and good mood as nature. Healing, cleansing forest and field air, which naturally helps a person get healthy and keeps his body in order. Less and less time is allocated for this. Therefore, it is so important to pay attention to at least abundant landscaping in cities: planting flower beds, improving lawns, creating public gardens and parks, planting shrubs and trees along the roads. And, of course, you shouldn’t forget about your own apartment; there should also be green friends in it, not only to disinfect the air in the room, but also to give joy with their appearance. What is important to us in plants is not only their natural phytoncides, but also their aesthetic appearance, right?
Phytoncides.
Many higher plants produce protective substances that have an antibiotic effect not only upon direct contact, but also at a distance.
Phytoncides(from Greek φυτóν - “plant” and Latin caedo - “I kill”) - biologically active substances produced by plants that kill or suppress the growth and development of bacteria, microscopic fungi, and protozoa.
Phytoncides are a natural defense for plants in cases of injury.
These substances were discovered by the Soviet biologist B.T. Tokin and called them phytoncides. Subsequently, it was found that antibiotic substances are produced by various bacteria, algae, and animals. Tokin discovered 282 species of higher plants, the volatile phytoncides of which have an antibiotic effect.
It has now been established that they have a phytoncidal effect to one degree or another. all plants. The phytoncidal activity of different plants is not the same and depends on the type of plant, location and growing conditions, phase of the growing season, and methods of using plant mass.
Many phytoncides are isolated in pure form, their structure is known, some are already synthesized. In this regard, much attention is paid to the mechanism of their action. The initial assumption that phytoncides have much in common with essential oils turned out to be inaccurate, since a significant amount of phytoncides was obtained from plants that are not essential oil plants. In most cases, phytoncides seem to act as a whole molecule; Some drugs are active as a result of the formation of hydrocyanic, benzoic and other acids.
Phytoncidal properties a number of plants are caused predominantly by any “main” group of chemicals (or even one substance): tannins, alkaloids (for example, the steroidal glucoside alkaloid tomatine, obtained from tomato leaves), organic acids, quinones (for example, juglone, 5-hydroxy- 1,4-naphthoquinone isolated from walnuts, or 2-methoxy-1,4-naphthoquinone from garden balsam), glucosides, essential oils, balms, resins, etc.
In some cases, for example in cherry laurel, the chemical composition of phytoncides is very close or coincides with the composition of the essential oil of a given plant, but essential oils and phytoncides cannot be equated. Thus, the production of phytoncides is also characteristic of plants that do not belong to essential oil plants (for example, oak, molds, etc.); on the other hand, the phytoncidal properties of plants rich in essential oils (for example, black currant) are not due to the essential oil (it does not affect microorganisms located on the plant).
In some cases, phytoncides are formed in a plant from inactive substances as a result of rapidly occurring chemical reactions. It has been established, for example, that garlic contains the inactive substance alliin, which, under the influence of the enzyme allianase, can quickly be converted into allicin, which has phytoncidal properties. It was found that volatile phytoncides of rose hips are formed when they are wounded, when the agluconic fraction of flavone glucosides contained in the fruit interacts with ascorbic acid.
In most cases, the impact on the bacterial flora of phytoncides isolated in pure form is lower than the impact on this flora of a plant containing this phytoncide. This suggests that plants most often contain several phytoncides. In addition, it has been proven that the activity of phytoncides in different plants is directly related to the content of various alkaloids, glucosides, essential oils, saponins, organic acids, enzymes, etc. It has been established that when certain conditions are created, some plant chemicals can be activated. Any phytoncide has antibiotic properties.
Many of the phytoncides have a beneficial effect on the animal body. For example, some of them promote the formation of ascorbic acid in tissues.
In large doses, phytoncides are poisonous to animals. In some cases, toxicity is caused by the phytoncides themselves, and in others by other substances supplied along with alkaloids, glucosides, etc.
In the quantities in which they are found in plants, they are practically harmless.
Phytoncides of forest plants have provitamin properties. The special significance of phytoncides is that they help attract the natural forces of the body.
Special phytoncidal preparations obtained from plants are of great importance, for example imanin- an antibacterial drug made from the St. John's wort plant, etc. Such special stable drugs with permanent action are extremely necessary. Natural phytoncides do not always have this property, the activity of which depends on the growing conditions of the plant, its collection, storage, etc. For example, burnet roots collected in the fall are more effective than those collected in the spring.
Phytoncides are used in medicine, agriculture, and the food industry. For example, eucalyptus phytoncides - for purulent surgical diseases (the use of phytoncides in this case gives good results, since along with the effect on the microflora, phytoncides stimulate tissue regeneration). The drug imanin is used in the treatment of wounds, burns, etc. Phytoncidal preparations from pine needles and some other plants are used in gynecology. Phytoncides contained in plant or fragrant substances, resins, balms can be used to purify the air from pathogenic microorganisms both in homes and in public places.
The most powerful phytoncides are possessed by: calamus, yarrow, wormwood, juniper, horsetail, linden, plantain, angelica, Abraham tree, eucalyptus, basil, St. John's wort, centaury, tansy, burial ground, violet, poplar (leaves and buds). These plants retain phytoncides in a dried state. The use of extracts from these plants is of great interest for cosmetics.
At the same time, the phytoncidal effect of essential oils, resins, resin-containing substances, balms, etc. is of particular interest for cosmetology.
We became acquainted with some facts about the powerful bactericidal, protistocidal and antifungal effects of phytoncides. At first, the bactericidal power of phytoncides, the speed of distribution of volatile phytoncides in the air, the speed of their penetration through the surface layers of cells, etc., seemed incredible to many. Let us remember the tuberculosis bacillus. In dried sputum, this microbe remains viable for 3 to 8 months; proven antiseptics such as carbolic acid in a 5 percent solution or sublimate in a 0.5 percent solution kill the tuberculosis bacillus only after 12-24 hours. Within 10-30 minutes, this microbe does not die in a 10-15 percent sulfuric acid solution. Of course, it is surprising that such a persistent microbe is killed outside the body in the first five minutes by phytoncides... of garlic!
Is there something mysterious, supernatural in this? Until the phenomenon is fully understood, it seems mysterious. But this is no more mysterious than, say, the effect of hydrocyanic acid or hashish on the human body or the role of vitamins in the body, etc. For millennia, no less mysterious facts with onions were known even before the discovery of phytoncides, only these facts became familiar and did not stop attention to yourself.
Are the tears a housewife sheds when cutting an onion any less mysterious than the speed at which onions kill bacteria? The housewife's "crying" is caused by the fact that the volatile substances of the onion spread extremely quickly and cause a response - the release of tears. Or let’s remember the speed of action of mustard plasters. We are not surprised by these ordinary facts. The news about the rapid action of phytoncides initially raised doubts even among highly qualified chemists. Meanwhile, it is chemists who have to remove the veil of secrecy that shrouds the new chapter of science - phytoncides, in the interests of the theory and practice of healthcare, veterinary medicine, plant growing and many other areas of human activity.
Scientists have conducted many experiments in the last decade to clarify the chemical nature of phytoncides, and yet we must consider that we are only at the very beginning of research in this area.
More fortunate were the bactericidal drugs - penicillin and gramicidin. Without exaggeration, we can say that a whole army of chemists is attacking the mold fungus - penicillium and the microscopic soil bacterium Bacillus brevis, from which gramicidin is obtained. The phytoncides of these organisms have been isolated in crystalline form, and the chemical nature of these healing substances has been determined with great certainty. Gramicidin turned out to be a substance belonging to the so-called polypeptides (substances close to proteins). These are, so to speak, protein fragments that include amino acid residues - valine, leucine, ornithine, phenylalanine and proline. The chemical nature of penicillin is also known. These are huge achievements of science.
The chemistry of phytoncides of higher plants, and especially their volatile fractions, is much less developed. Soviet scientists are pioneers in the study of the chemistry of phytoncides of higher plants. Detailed work has been carried out on phytoncides of onion and garlic. I.V. Toroptsev and I.E. Kamnev isolated a bactericidal preparation from garlic in the form of powder and solutions. T.D. Yanovich received a garlic extract - sativip, which attracted the attention of many doctors.
American scientists in 1944-1945 extracted the bactericidal drug allicin from garlic and suggested its chemical nature.
In 1948, active bactericidal substances in garlic were artificially created (synthesized) in Switzerland.
There are at least ten other attempts by chemists from different countries to find out the exact composition of garlic phytoncides. So far, however, this work has not yet been completed with complete success. More than ten drugs have been created from garlic, but each of them differs from each other in chemical composition and in its effect on microbes, and all of them are inferior in their antimicrobial power to the natural tissue juice of garlic and its volatile phytoncides.
The chemical composition of garlic and onion phytoncides is still unknown. It has only been found out that the active bactericidal substances are not of a protein nature. According to I.V. Toroptsev and I.E. Kamnev, garlic phytoncides are similar in chemical nature to glucosides, substances widespread in the plant world. A substance has been isolated from garlic that suppresses bacteria already at a dilution of 1:250,000. It is called alliin. It is an oily liquid, soluble in alcohol and ether, but poorly soluble in water. It consists of carbon, oxygen, hydrogen and sulfur. Chemists write this:
However, it is wrong to think that this is garlic phytoncide. At best, it is one of the components of a complex complex of substances, which is a phytoncide.
Phytoncides can be more complex in their composition. In any case, it is known that phytoncides of garlic and onion do not represent only one compound: they can also be a complex of substances. The juices of garlic and onions, non-volatile at room temperature, differ in composition from the volatile phytoncides of the same plants. The chemistry of volatile phytoncides is least known. Although we have only more or less educated guesses regarding the composition of phytoncides, one thing is clear: the chemistry of phytoncides from different plants is very different. We judge this by their different biological effects on micro- and macroorganisms 1 .
1 (Macroorganisms mean all plants and animals, except microbes)
However, plant antimicrobial substances may be very simple compounds. Thus, R. M. Kaminskaya isolated the phytoncidal substance C 11 H 18 from juniper. It kills E. coli, the causative agents of typhus and paratyphoid A and B, the causative agent of diphtheria, and the dysentery bacillus. Natural juniper phytoncides, however, are unlikely to consist only of this substance.
The study of the composition of volatile phytoncides led to a tempting idea: compare them with essential oils of plants. In the first years of research, the author was convinced of the need to identify volatile phytoncides with essential oils. Subsequently, it turned out, however, that volatile phytoncides and essential oils cannot be identified, although they may be related to them in origin.
Many experiments in our and other laboratories have convinced us that not only essential oil plants, but also plants that do not contain essential oils have excellent phytoncidal properties; wounded oak leaves, for example, are very good at killing various microbes at a distance.
Some essential oil plants have a very weak ability to kill microorganisms. Thus, phytoncides from the leaves of the well-known geranium kill protozoan single-celled organisms very poorly, only within hours. By the way, it is absolutely not necessary for plant substances that have a smell to have phytoncidal properties.
How are essential oils obtained?
The main method is steam distillation of essential oils. We need to obtain, for example, essential oil from eucalyptus leaves or from the peel of a lemon fruit. Let's prepare the raw materials. Grind it and expose it to hot steam. The essential oil, contained in microscopic particles in special containers called glands, protrudes and is extracted by steam. The oil is collected in special vessels, sometimes purified with chemicals and distilled a second time with hot steam. The result is an oily liquid, almost insoluble in water; on paper, like sunflower oil, it leaves a stain.
Let us now assume that in a plant, for example black currant, volatile phytoncides and essential oil are the same combinations of substances. In order to understand the chemical nature of volatile phytoncides, the just described method of distilling essential oils should be considered very bad: when exposed to hot steam, some of the components of volatile phytoncides change.
Essential oils are distilled not only from fresh material, but also from dried material.
What remains there of natural, naturally volatile phytoncides?
After all, there are plants (onions and others) that spend almost all of their volatile phytoncides in the first minutes after chopping. It is clear that scientists, when distilling essential oils from such plants, do not obtain natural phytoncides, but some highly modified products.
Scientists, through ingenious and painstaking experiments, have become convinced that volatile phytoncides and essential oils are not necessarily the same substances. Let's talk about one such study on blackcurrant leaves.
With a thin metal needle or a sharply sharpened wooden needle, it is possible to remove all the glands with essential oils. To completely remove traces of essential oil, you can wipe such a sheet with blotting (filter) paper. If you rub such a leaf between your fingers, the smell of essential oil will not be detected. And such a leaf without traces of essential oil still continues to release volatile phytoncides and kill microbes from a distance.
It has also been proven in other plants that phytoncides and essential oils, even in essential oil plants, are different groups of substances.
So, it is absolutely clear that essential oils obtained in various ways, of course, are not the totality of substances that are secreted by a living plant. It is no coincidence that essential oils are poisonous to the plants from which they are isolated. Thus, anise, rosemary and lavender plants die from the vapors of their own essential oils.
In the same way, bactericidal principles obtained in various other ways from lower and higher plants can hardly be entirely identified with the totality of bactericidal substances that are produced during the life of the plant. All of these are more or less “mutilated” phytoncides. It is all the more interesting to recall some data on the bactericidal properties of plant essential oils. These properties have long been known, but they were not given the importance that they have.
The bactericidal properties of eugenol, vanillin, rose, geranium and other oils were known. In Russia in the 80-90s of the last century, sterilization of catgut (threads of animal origin used in surgery) with essential oils of coniferous plants was used. The author's laboratory has conducted numerous experiments to determine whether essential oils act on microorganisms at a distance, that is, whether microorganisms are killed by vapors of essential oils.
Experiments have shown that vapors of essential oils successfully kill microorganisms. Vapors from the essential oil of the oregano plant stop the movement of ciliates within 1.5-2 minutes. Vapors of gray wormwood essential oil kill ciliates in 30-60 seconds; Bogorodskaya grass - after 1-1.5 minutes; snakehead and hyssop - in the very first seconds. Vapors from essential oils of some plants kill typhoid and dysentery germs.
A lot of interesting things have already been discovered about the chemistry of phytoncides. The Kyiv scientists B. E. Aizenman, S. I. Zelepukha, K. I. Beltyukova and others, led by the famous Ukrainian microbiologist Academician Viktor Grigorievich Drobotko, worked the most.
As one would expect, in most cases, phytoncides are not one particular substance, but a set of substances, specific to each plant.
Substances that are often found in plants and have long been known to science have antimicrobial properties - tannins, alkaloids, glucosides, organic acids, balms, resins, hydrocyanic acid and many others. But, as already mentioned, phytoncides are most often a complex complex of chemical compounds.
Let's give examples.
The main active principle of bird cherry phytoncides is hydrocyanic acid, but in addition there are benzoaldehyde and unknown substances.
It would seem that the phytoncidal properties of oak leaves can be easily explained by the fact that their tissue sap always contains tannins. These substances actually inhibit growth and kill many bacteria. In fact, phytoncides from oak leaves are far from just tannins. Tannins are almost non-volatile, while oak leaves kill many bacteria from a distance.
Interestingly, in most cases, phytoncides are not proteins or nucleic acids.
There is a lot of mystery in the chemistry of phytoncides. Some plants, when dying, gradually lose their phytoncidal properties, while others retain them for a long period.
The mysterious phenomenon of exceptional “survival after death” of some trees is worthy of surprise. Larch lives for 400-500 years, and after death its wood survives for hundreds and even thousands of years. The State Hermitage Museum in Leningrad contains logs of grave crypts and chariots with wheels woven from larch roots. These products have lain for more than 25,000 years, and bacteria and fungi have not touched them. Why? Are phytoncides mixed in with this mysterious phenomenon?
We will not delve further into the field of chemistry. It may happen that some plants contain substances in their phytoncides that are still unknown to chemistry. This is what they think, in particular, about some of the components of garlic phytoncides. However, we will not engage in unnecessary prophecies: we must patiently wait for the results of research and be imbued with respect for the work of chemists, which is often heroic. Let impatient people who demand a quick answer about the chemical composition of phytoncides know that the chemical composition of plants is sometimes extremely complex. The history of science shows that it took many years, even decades, to determine, and even then incomplete, the chemical composition of the essential oil of some plants. Chemists, studying phytoncides, will do a lot of useful things for medicine, veterinary medicine and agriculture.
Before starting this chapter, we remembered the wonderful words of our great naturalist Ivan Petrovich Pavlov: “Facts are the air of a scientist.” This sounds like a commandment for our and all future generations of scientists. Both the author and the reader can be completely calm about the accuracy and abundance of facts obtained by many researchers in the field of phytoncides. The reader’s thoughts can legitimately rush to get answers to many questions that have arisen related to understanding the role of phytoncides in nature itself, with the significance of the discovery of phytoncides for science, medicine, and industry. We will try to answer some of these questions soon, but we will not touch on the central biological question - about the importance of phytoncides for the life of plants themselves - at the end of the book, when we have much more facts about the properties of phytoncides than we have now.
If phytoncides were found only as an exception, on one or two plants, they would not be of particular biological interest.
How can we explain such generous extravagance of the plant world? Let's jump ahead and first make one very important assumption that makes an attempt to explain why phytoncidal properties appeared during the evolution of plants and what their role is in nature.
Any plant, be it mold or birch, bacteria or oak, in the course of its life produces substances - phytoncides, which help it, along with other numerous devices, to fight against bacteria, fungi and certain multicellular organisms that may be harmful to it. Phytoncides and, figuratively speaking, the plant sterilizes itself.
Thus, by phytoncides we agree to understand plant substances of various chemical natures that have the properties of inhibiting the development or killing bacteria, protozoa, fungi and other multicellular organisms and organisms that are important in protecting plants from diseases, that is, playing an important role in the natural immunity to infectious diseases.
