Informatioin Office of the Research Institute of Fungi
Shanghai Teachers University

PSP and PSK are the 2 products of Yun Zhi ratified by Chinese Ministry of Public Health and Japanese Ministry of Public Health respectively.

PSK was first manufactured by Kureha Chemical Industry Co. Ltd.   The PS in PSK represents polysaccharide and K represents the first alphabet of the name of this Company.   It was originally written as PS-K and was later changed to PSK.  o; The commercial name of the product is Krestin.

PSP was prepared by Professor Qing-yao Yang.   It is like PSK and is also a kind of compound polysaccharide.   On the molecules of the polysaccharide, the small molecular protein (polypeptide) is connected.   So it is called Yun Zhi Duo Tang Tai or Yun Zhi Tang Tai.   The Tang Tai English names were originally glycopeptide, proteoglucan, glycosaminoglucan, etc.   But the polysaccharide is all composed of N-acetyl-amino-hexose.   But the polysaccharides of PSP and PSK are not composed of N-acetylamino-hexose.   So it is not suitable to use the name.   So the word "polysaccharopeptide" or "polysaccharide-peptide" is used and is abbreviated as PSP or Ps-p.

According to the different degrees of extraction, there are a series of PSP products.   PSP directly extracted from the mycelia of Yun Zhi is called Yun Zhi Polysaccharide-peptide (Trade mark Qing Kang) and PSP polysacchardie-peptide (Landford).   The former is sold on the market of Mainland China and the latter is according to the export specifications and is sold overseas.   These 2 products are mainly used for tumorous patients.

The essence of the product is obtained by further isolation of the crude product.   It is called Essence of Mushroom (Yun Zhi) (The sole distributor is Winsor Health Products Ltd., Hong Kong) used for healthy purposes.

Japan is quite specialized in the research of Yun Zhi.   Besides PSK, Hirose, S. et al, (1970), Naruse S. and Takeda S. (in 1970) and Sugiura M. (in 1980) isolated two anticancerous components of the mycelia of Yun Zhi respectively.   The former is called ASTO and latter D--II.   In addition, Ito H. et al (in 1974) extracted from the fermented mash of Yun Zhi an anti-tumor component which does not contain protein and it is called Coriolan.   Its chemical components are glucans (by Hayashida S. et al, in 1992).   But the above-mentioned three components still remain in the process of pharmacological research and was not used in clinical application.

Though PSP and PSK are all a kind of protein bound polysaccharide and are all extracted from the deep layer cultivated mycelia, yet they use the different strains, fermented medium and different extracted methods.   Thus there is a certain difference between PSP and PSK.   It is known that in the polysaccharide of PSP there is fucose, while there is no fucose in PSP, which contains arabinose and rhamnose; while there are no such ingredients in PSK.   On the other hand, according to the pharmacological and clinical research, PSP has the definite effect of alleviating pain and increasing appetite, while there is no such report on PSK.

Comparison of Two Characterisitics of PSP and PSK
Items compared Similarities Dissimilarities
Fungi Yun Zhi Coriolus versicolor (Fr.) Quel PSP: Cov-1 strain
PSK: CM-101 strain
Drug produced PSP: capsule
PSK: loose package
Powder color brown PSP: brown
PSK: dark brown
Raw materials deep-layer cultivated mycelia (2N)
with glucose as the main carbon
source (25oC, 3 days)
PSP: nitrogenous source: soya bean
cake powder
PSK: nitrogenous source: peptone
and yeast cake
Extract and
obtained by immersion in hot water PSP: isolate by alcoholic
PSK: isolate by salting out with
protein bound polysaccharide;
average molecular wt. 1 x 105 Da
the polysaccharide is formed from
many monosaccahrides containing
alpha-1,4 and beta-1,3 glucoside
Peptide mainly consists of aspartic
and glutamic acids
PSP: polysaccharides contain arabinose
and rhmanose, but no fucose
PSK: polysaccharides do not contain
arabinose and rhamnose, but
contain fucose
inhibit the synthesis of nucleic acid
of Ehrlich ascitic cells, and inhibit
the accretion of cancer cells of
Sarcoma-180, P388 leucocytes, etc.
PSP: inhibiting rate on P388 is
90-96% (1mg/kg)
PSK: inhibiting rate on P388 is
61-90% (1mg/kg)
recover the delayed supersensitive
reaction inhibited by chemotherapeutic
drugs such as cyclophosphamide
and raise the lowered no. of WBC.
The inhibiting rate of PSP on
Sarcoma-180 of Kunming mice is
43%; PSK, 28%.
obviously raise the activity of NK cells
and macrophages, raise the contents
of immunoglobulin, complement C3,
antibody HC50 and IL-2 and promote
the increase of T-lymphocytes
PSP can increase the alpha and
gamma interferons produced by
WBC by 2 to 4 times
Toxic test LD50>20g/kd; Ames test and
the tests of abnormal chromosomes,
nucleotide, reproduction, and
abnormality are all negative.
Use 50 times clinical dosage for
monkey, consecutively for 6
months, no toxic reaction.
PSP can produce the toxic reaction
by making the aggregation of the
chromosomes of the lung cancer cells,
but there is no toxic function on
the hamster cells of normal mice.
lessen the toxic and side reactions
of chemo- and radiotherapy, raise
the immune function, promote
curative effect, prolong life
and raise the quality of life
PSP can not only increase appetite,
but also relieve pain.

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