what is the structure of bamboo kun?

Question

There are claims that the bamboo fiber has inherent antibacterial properties due to "bamboo kun". However I could not find anywhere what is the chemical composition of this "bamboo kun" and also no evidence to substantiate the antibacterial claims.

Does anybody know if bamboo kun is a myth or it really has a known chemical structure?

Edit1:

• check out wikipedia: https://en.wikipedia.org/wiki/Bamboo_textile

Bamboo also contains a substance called bamboo-kun – an antimicrobial agent that gives the plant a natural resistance to pest and fungi infestation

• google books: https://www.google.com/search?tbm=bks&q=bamboo+kun

Edit2:

Also I could not find this Japan Textile Inspection Association which lots of sites making the antibacterial claim above are citing as the source of antibacterial validation (although there is a Japan Textile Federation that has nothing to do with the above claims):

• http://www.bambrotex.com/second/bc_nab.htm
• https://www.textilemates.com/bamboo-fibre/
• https://highlineorganix.com/pages/why-bamboo
• https://www.weber-textilien.ch/bademantel/50-210-bambou-bademantel-mit-schallkragen.html
• https://web.archive.org/web/20111005122758/http://www.fashionandearth.com/us/bamboo-clothing-facts.html

Answer 1

It is not implausible that bamboo should have antibacterial properties, after all plants generate lots of protective chemicals. However, the use of this particular word (kun or kunh) by a number of commercial textile websites seems like a promotional gimmick without a strong scientific basis.

Claims of an intrinsic antimicrobial property of processed bamboo fibers are likely exaggerated, as the excerpt below (1) suggests:

3.3. Antibacterial Properties

The antibacterial properties of the control sample (OB) and the composites (ZB, GB, ZGB) were qualitatively investigated by the bacteriostatic circle method against one Gram-negative (E. coli) and one Gram-positive (B. subtilis), and the results were shown in Figure 6. Figure 6A displayed the antibacterial activities of bamboo samples against E. coli. It can be observed that OB had little antibacterial activity without an inhibition zone.

This is not to say that bamboo lacks antimicrobial properties. Plants employ a myriad of chemical substances as sources of physical and chemical protection. Extracts of bamboo (2) apparently contain bactericidal compounds, although the concentration in processed fibers appears insufficient to grant these significant antibacterial properties.

It's also worth adding that the above refer to specific species of bamboo and there may be significant variety in antibacterial properties across species.

In conclusion it is difficult if not impossible to answer the OPs question as it is unclear what "kun" or "kunh" refers to, it may just be a catchphrase to describe unknown substances granting antibacterial properties to raw bamboo.

References

1. Junyi Zhang, Bo Zhang, Xiufang Chen, Bingbing Mi, Penglian Wei, Benhua Fei, and Xindong Mu. Antimicrobial Bamboo Materials Functionalized with ZnO and Graphene Oxide Nanocomposites. Materials (Basel). 2017 Mar; 10(3): 239. doi: 10.3390/ma10030239

2. The origin of the antibacterial property of bamboo. T. Afrin , T. Tsuzuki , R.K. Kanwar & X. Wang. The Journal of The Textile Institute. 2012; 103(8): 844-8491. doi: 10.1080/00405000.2011.614742