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[Note, the following paper by Dr. Krebs, can also be found along with other important details about the story of Laetrile and metabolic therapy in Maureen Salaman's book: Nutrition, The Cancer Answer, Statford Publishing, 1259 El Camino Real, Suite 1500, Menlo Park, California 94025.]

The Extraction, Identification and Packaging of Therapeutically Effective Amygdalin

Extracted from a compendium of papers written by Dr. E. T. Krebs, Jr. co-discoverer and developer of Laetrile-amygdalin, for the John Beard Memorial Foundation


"Words can conduce to a better knowledge of the subject; they cannot always enforce a standard of excellence in the implementation of such knowledge" Dr. E. T. Krebs, Jr., D. Sc. May 7, 1979

The Prevention and Control of Chronic Metabolic Disease Has Always Been Accomplished by Means Common to Man's Biologic Experience.

Without becoming involved in the unitarian or trophoblastic thesis, suffice it to say cancer is a dietary deficiency disease involving a specific deficiency, at a cellular level, of pancreatic enzymes and vitamin B 17 (with associated A and C and other vitamin, mineral and trace element deficiencies.)

Just as nothing foreign to biological experience has ever prevented or cured any chronic metabolic disease, the prevention

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or cure of the disease has always involved supplying the deficient factor, either water or oil soluble, in the same molecular form as obtained from man's normal surrounding biological environment.

Within a theoretical context (the unitarian or trophoblastic theses of cancer) which we need not consider here, Dr. E. T. Krebs, Sr. and myself deduced the relevance of amygdalin (vitamin B 17) *as it occurs in nature* to the possible prophylaxis, palliation and therapy of cancer in man and animal.

Pursuant to this deduction, we prepared pure amygdalin in the Krebs' laboratories in the 1940's, did comparative toxicity studies, found it non-toxic in doses appropriate to human and animal needs, and then proceeded to study the material clinically.

From the first, those of us involved in the clinical tests were aware that the *amygdalin molecule occurring in nature*, and common to human biologic experience in hundreds of edible seeds and plants, is unstable during and after extraction from its natural source. The slight variations in extracting procedure cause many of the amygdalin molecules to change to a form unknown to nature. These are known as isomers(1). Such a conformation is called neo-amygdalin. A mixture of natural amygdalin molecules and neo- amygdalin molecules is called isoamygdalin. This unnatural iso-amygdalin which is the result of poor extraction technique, caused unpredictable, often severe, reactions in our patients.

All of our successful therapeutic studies were conducted using only pure natural amygdalin.

With no exceptions, all theory and successful practice in amygdalin therapy is based upon the clinical use of pure natural amygdalin.

Scientific Facts Cannot Be Written to Suit Expediency

There are today individuals, manufacturers, and purveyors who label their iso-amygdalin products amygdalin contrary to all of the recognized specifications for the natural vitamin substance
(1) Isomer one of two or more distinct compounds which possess the same molecular formula, each molecule containing the identical atoms of each element but in a different arrangement. [page 2]

which is the only true amygdalin. Whether they do this for commercial or political purposes, they certainly cannot justify such fallacy on any rational basis. This scientific heresy and commercial fraud, for it can be called no less, has resulted in tremendously reducing the effectiveness of amygdalin therapy.

Amygdalin is as Defined in the Merck Index and All Scientific Compendia. Any Other Specification is Not Amygdalin.

The identity of amygdalin has been known, with an increasing degree of sophistication, for over 150 years. Its identity over this span of time has not changed. It is defined and explicated in terms of optical activity, molecular weight, chemical composition, and other means of identification in literally hundreds of compendia, papers, encyclopedias and the like in virtually every country of the world.

At one time or another, it has been official in the great pharmacopoeias of the world. Its qualities and identity are irrevocably established. Any compound that is labelled amygdalin should represent but one thing - amygdalin. To the extent that any compound so labelled deviates from what the world accepts as amygdalin, that compound is properly described by all vigilant regulatory agencies as adulterated. Adulterated foods and drugs are subject to confiscation, and their purveyors to prosecution.

Only the Natural Laevo Amygdalin Has Proven Therapeutic Value.

The slightest deviation of compound from that standard which normally identifies it may spell very far reaching physiological and/or pharmacological consequences. I give you a photocopy of page 341 of Paul Karrer's "Organic Chemistry" (Elsevier Publishing Co., Inc., N.Y. 1950). Look at the simplistic structure of D-Glucose. Compare it with that of D-Galactose and compare both to D-Mannose. Glucose is chemically identical with D- Glucose, except that on the 4th carbon atom the hydroxy group in one compound is disposed as the mirror image of the other. Then [page 3]

in Mannose on the second carbon atom the hydroxy is on the left compared to that on the right for D-Glucose. (Table A) [NB:Table not scanned yet.rsc]

But what difference does it make-medically at least? In relieving hypoglycemic symptoms, galactose, for example, is very much less effective than D-Glucose while mannose, for reasons not fully known, is just about as effective as D-Glucose in relieving such symptoms. Reliance upon D-Galactose in the place of D-Glucose-even if you called the former an iso-glucose or a neo-glucose---could allow the patient to die from unabated hyperinsulinism. (Herring, P.T., J.C. Irvine, and J.J.R. MacLeod --- The efficiency of various sugars and their derivatives in relieving the symptoms caused by insulin in mice. *Biochem J 18*:1023, 1924).

In amygdalin the disaccharide gentiobiose is stereochemically quite stable; therefore, we are presently not specially concerned with that moiety except in its attachment to the asymmetric carbon atom of mandelonitrile. I refer you to the enclosed structure of amygdalin from page 12 of McIlroy's "Plant Glycosides". Please note that in the flow-sheet of synthesis the end product is described as "l-rotatory amygdalin identical with natural amygdalin" (Table B). Note also that the stereoisomeric "unnatural form---non-amygdalin" is separated from the "natural" form by crystallization.

It Has Been Contended that the So-Called Amygdalin Preparations in International Commerce Are Not Actually Amygdalin. This Contention is Correct Because for the Greater Part They Are Iso-amygdalin.

Iso-amygdalin was first prepared by the action of alkali on amygdalin by Walker ( 1903, 1909). Iso-amygdalin is accidentally produced through less than efficient or careful extraction processes for amygdalin.

Put very simply, so called iso-amygdalin is approximately 50 percent amygdalin and 50 percent non-amygdalin (neoamygdalin). It does not follow from this that iso-amygdalin is only 50 percent less therapeutically effective than amygdalin. Our laboratory and clinical experience suggest a far greater loss. [page 4]

Iso-amygdalin is Less Than 50 Percent as Therapeutically Effective As Amygdalin.

Clinically, the results obtained from amygdalin therapy have deteriorated over the years as the quality and methods of production and packaging have become progressively abominable until therapeutic efficiency is today less than one third that of the lyophilized Laetrile produced by Krebs and Delmar Laboratories.

The reduction in clinical efficiency is the direct responsibility of manufacturers who either out of concern for profit, or lack of concern for the product, have provided inadequate extraction facilities and personnel, the result is spoiled production which they package and label as amygdalin.

The Necessity to Maintain The Natural Configuration for Clinical Effectiveness is not Unique to Amygdalin.

We know no instance in biology or medicine in which an "unnatural isomer" can be accorded equivalence with a natural one.

Consider thyroxine, L-thyroxine is the physiologically active stereo-isomer. In the case of epinephrine, which is laevo-rotatory to polarized light, we find the dextro-rotatory isomer has only about one-twelfth the action of the natural or laevo compound. There are the closely related Synephrins: while Synepherin rotates polarized light to the right: Neosynephrin rotates it to the left. The latter compound is much more active and has generally replaced Synephrine.

Atropine is a racemic (2) hyoscyamine; that is, it consists of equal parts of laevohyoscyamine and dextrohyoscyamine; the action of atropine is practically that of its laevohyoscyamine half. In plants, atropine does not itself exist; the laevo-hyoscyamine is racemized in extraction. Shades of iso-amygdalin! The ester of atropine and mandelic acid is known as homoatropine. Laevo isomers, both of them.
(2) A racemic mixture is a 50/50 mixture of laevo and dextro rotary forms of a compound, i.e. mirror images of each other. The term is sometimes used to refer to a simple mixture of isomers.

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Nowhere in Living or Biological Systems is There an Equal Tolerance for Natural and Unnatural Isomers. The Unnatural Mixtures are Always at Least 50 Percent Inferior to Pure Preparations of the Natural Isomer.

*Iso-amygdalin is not amygdalin*. It is spoiled amygdalin. It is therapeutically as unsound as racemized epinephrine, racemized thyroxine, racemized Synephrine, racemized hyoscyamine, or the like. In the case of atropine the "equal part" of dextrohyoscyamine is physiologically dead or inert. But suppose it were more than this? Suppose that it inhibited the laevohyoscyamine half?

In the case of unnatural forms of amygdalin (iso-amygdalin or neo-amygdalin) used for antineoplastic effect how do we know that the unnatural isomer does not render the natural one inert? Is it not entirely possible that neo-amygdalin (3) acts as an anti-vitamin destroying or inhibiting the metabolic pathway of natural amygdalin? At the very worst; could neo-amygdalin, in common with many products modern man ingests that are not included in his biological experience, actually be carcinogenic or promote metastasis? Until the answers to these questions are known it is prudent to avoid all but natural amygdalin.

Sooner or later some regulatory authority will correctly accuse distributors of iso-amygdalin of "watering the milk": charging for amygdalin and supplying about 50 percent of it as the inferior isomer. In all of organic nature there is simply no such thing as the natural isomer of an optically active compound having the same physiological characteristics as the unnatural form.

Of All the Seventeen or More Water or Oil Soluble Vitamins, There is No Such Thing as a Deviance From the Naturally Occurring Structure Proving Anything More Than Unsatisfactory or Inert.

We are going to be called, as I have been in the past, to go to a blackboard to write out the entire structural formula of amygdalin in explicit detail down to the identification of the isomer. If any manufacturer or purveyor is going to fool with any structural deviation from actual amygdalin then he has the scientific and regulatory responsibility of specifically identifying the "unnatural
(3)Neo-amygdalin is the pure isomer to which many natural amygdalin molecules are converted during inexpert extraction. Iso-amygdalin is an equilibrium mixture of approximately 46% natural amygdalin molecules and 54% neo-amygdalin molecules.

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molecule": being able to draw its total structure on a blackboard and being able to defend the identity of that structure with what carries the same identification in a commercial dosage form.

When I personally produced amygdalin I was able to demonstrate its conformity with the molecules as it occurred in the seeds or kernels from which it was extracted. Of course, I had the prior assistance of literally hundreds of chemists all over the world who for a century had exhausted all of the chemical and physical or optical properties of amygdalin in giving it as hard a definition as that for pure gold, any other element, or for water and dextrose.

Recall epinephrine (Adrenalin) where the natural form is twelve times more active than the unnatural form? An "iso-epinephrine" would be, approximately, a 40 percent (or greater) fraud on the purchaser.

Like amygdalin, extraction techniques for epinephrine may result in iso-epinephrine, as they do in the case of amygdalin for iso-amygdalin. Because of imperfect or sloppy extraction techniques one is left with two possible options when faced with such accident of extraction. One is to take the "iso" mixture and separate through crystallization one isomer from the other, and then prepare the natural isomer for packaging. This becomes relatively costly because the loss in recovering the pure natural isomer is about 60 percent more than stopping with the "iso form". If one stops with the iso form and goes ahead and packages it, the economic cost is about 70 percent less, the cost in human health and life may be incalculable.

To Mislabel Iso-Amygdalin as Amygdalin is Scientifically, Medically, and Morally Indefensible.

I would be tempted to greater tolerance, at this stage of our development, were it not for the fact that almost 20 years ago I produced pure amygdalin in kilogram quantities that measured up to all official standards working with equipment (short of

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lyophilization) that cost us less than $12,000.

We were really purists about it all---just as Parke Davis is with Adrenalin. When an accident of extraction occurred we simply ran the product down the sewer. Unquestionably this had much to do with the fact that our "therapeutic index" was about 80 percent higher than it is with deviant material on the market today---even when implemented by "metabolic therapy".

Packaging of Injectable Amygdalin is as Important as Extraction.

Even carefully extracted amygdalin is extremely unstable when placed in solution for storage or shipment. The slightest variances in temperature or pH will cause many of the molecules to change to the same unnatural configuration obtained by poor extraction procedure with the same attendant reduction in therapeutic efficacy. Amygdalin in solution of indefinite age is extremely unpredictable and should be avoided.

All Injectable Laetrile Amygdalin Must Be Lyophilized (Freeze Dried) Anything Else is Simply Not Laetrile--Amygdalin.

Freeze drying (lyophilizing) is the only presently available method of preserving the natural laevo amygdalin to be used parenterally for an indefinite period.

Historically no dosage unit of parenteral Laetrile amygdalin has ever been legitimately dispensed unlyophilized. Any vial or ampules containing an aqueous solution labelled amygdalin has by its very nature been mislabelled and should bear the label iso-amygdalin from which its lessened therapeutic efficacy could be deduced.

Three Grams of Amygdalin Can Not Be Dissolved, Much Less Shipped, in a 10 cc Ampule.

Currently the labelled three gram vial, or ampule, of amygdalin has become the standard unit for injection. These vials and ampules, each with a lOcc capacity, are an anathema to those individuals knowledgeable in stereochemistry and the technical specifications of amygdalin.

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By specification one gram of amygdalin will dissolve in not less than 12 ml. (lOcc) of water at room temperature. One is therefore led to the obvious conclusion that a lOcc vial, labelled to contain 3 grams of amygdalin, either contains much less than three grams or contains iso-amygdalin, which is far more soluble in water than natural amygdalin. Either conclusion means that the label of 3 grams amygdalin is fraudulent, and the clinical activity of the vial, if any, is far less than should be expected.

Lyophilization Makes Minimum Size Injections Possible.

The only exception to the chemical axiom of amygdalin solubility: 1 gram will dissolve in not less than 12 ml. of water at room temperature, is a special form of lyophilization. Lyophilization (freeze drying) of amygdalin will create a crystalline structure which is capable of being reconstituted in a much smaller amount of sterile water. The advantage of lyophilized amygdalin, for parenteral use, is obvious when one considers that it requires 36 ml. of water to dissolve 3 grams of amygdalin for injection. Three grams of lyophilized amygdalin can be reconstituted and injected in a far more reasonable and practical quantity.

It should be remembered that once in solution the lyophilized amygdalin will reassume the unstable characteristics of the amygdalin molecule and should therefore be injected as shortly after being put in solution as possible.

I Hope All This Has Been Helpful. Words Can Conduce To A Better Knowledge Of The Subject: They Cannot Always Enforce A Standard of Excellence in the Implementation of Such Knowledge.

It may be asked why we have not spoken out more strongly against the mislabelled, adulterated under-strength, products currently in commerce while the therapeutic index of success with amygdalin has continually decreased! F.D.A. regulation has made extraction of amygdalin in the U.S.A. illegal. The only manufacturing available has been on foreign soil and until now these sources have been woefully inadequate, but even these

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sub-potent products have given superior results to the cut, burn, and poison protocols of established medical practice.

In A Practical World We Must Often Accept Expedient Relief of Human Distress As Better Than No Relief At All. At the Same Time We Cannot Diminish the Energy With Whice We Strive Toward the Ideal Means of Relief.

As new sources become available clinicians will be careful to ascertain that the amygdalin proffered to them is natural amygdalin with the molecular structure found in man's normal surrounding biological environment.(4) Doctors will not be fooled by products that are presented in powdered or lyophilized form but are still composed of unnatural iso-amygdalin. It is only the natural amygdalin that we can be sure has antineoplastic effect.
(4) Doctors should demand a certificate of analysis from a certified laboratory. Optical rotation is a negative test only and is not acceptable by the National Cancer Institute, the F.D.A. or any technically knowledgeable laboratory as an index of pure natural laevo amygdalin. Optical rotation can be too easily altered by the addition, accidentally or on purpose, of such compounds as free glucose. The most accurate test to determine pure natural amygdalin is H.P.L.C. and 13C-NMR (according to Thomas Cairns et al., John K. Howie, and D.T. Sawyer, U.S. Food and Drug administration, Los Angeles, California 90015 and Dept. of Chemistry, University of California Riverside, California 92521.

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