# Biological Importance of Cotton By-Products Relative to Chemical Constituents of the Cotton Plant
## 6 Conclusions  
In this review, it has been shown that the whole cotton plant is a reservoir of a wide variety of compounds which have a range of biological functions and exploitable applications. The distribution of compounds in the cotton plant provides knowledge of the chemical content of cotton waste derived from harvesting and cotton ginning operations. Potentially valuable chemical compounds with application in food manufacturing, perfumery, and pharmaceutical industries are found in components of these cotton processing by-products (burr, leaves, crushed seeds, sticks, roots, and flowers of the  
\begin{table}
\begin{tabular}{l l c} \hline \hline \multicolumn{1}{c}{**Compounds**} & \multicolumn{1}{c}{**Biological Activity**} & \multicolumn{1}{c}{**References**} \\ \hline
2,3,9-trihydroxy-1,3,5,7,9- & Phytoaxelin & [99] \\ cadinapenten-14-al; 3-Me ether & & \\ \hline
2,8,9-trihydroxy-1,3,5,7,9- & Antifungal activity & [92] \\ cadinapenten-14-al; 8-deoxy & & \\ \hline Phenols & & \\ \hline chlorogenic acid & Anti-oxidant and anti-mutagenic activity & [144] \\ \hline gallic acid & Antioxidant activity, cytotoxic activity & [189,190] \\ \hline
4-hydroxybenzoic acid &
\begin{tabular}{l} Anti-microphal activity, used as preservative, oestrogenic activity, \\ anti-inflammatory and anti-oxidant activity \\ \end{tabular} & [175,176,191] \\ \hline gossypol; (+)-form & Contraceptive and hypokalemic activity & [30,192,193] \\ \hline
3,3\({}^{\prime}\)4,5,7,-pentahydrooxyflavan; & Cytotoxic and phytotoxic activity & [194,195] \\ (25,3R)-form & & Enzyme inhibitor, cytotoxic, anti-oxidant activity & [196] \\ \hline scopoletin & Anti-spasmodic and anti-inflammatory activity & [19] \\ \hline Fatty acids & & \\ \hline
11,14-eicosadienoic acid & Hormonal activity & [18] \\ \hline hexadecanoic acid & Anti-microphal and anti-inflammatory activity & [197] \\ \hline octadecanoic acid & Pharmaceutical excipient, surfactant and softening activity & [198] \\ \hline
9-octadecenoid; (Z)-form & Insecticidal, anti-bacterial and fungicidal activity & [199,200,201] \\ \hline tetradecanoic acid & Defoaming agent, flavour adjuvant used in food processing & [202] \\ \hline Carbohydrates & & \\ \hline cellulose & Capsule and tablet diluent & [203] \\ \hline Proteins & & \\ \hline
3-phosphoglycerate phosphatase & Enzyme activity & [119] \\ \hline vicilin & Anti-hyperterhesive activity & [204] \\ \hline \hline \end{tabular}
\end{table}
Table 2: _Cont._cotton plant). Gossypol, which is known to have contraceptive properties is not only concentrated in the seeds of cotton, but occurs in the roots and possibly in other parts of the plant. Phenolic compounds and terpen present in the cotton burr stem, leaves, flowers, stalks, and roots have insecticidal, herbicidal, and phytotoxic properties that could be exploited. This review has highlighted that cotton waste products can be sources of biologically valuable compounds. Special consideration should be given to CGT as a low cost resource because it is centrally stockpiled and collocated with existing infrastructure. Therefore, investigating the occurrence of these chemical compounds in cotton by-products can contribute to recycling and value adding of waste generated from cotton ginning.  
The authors wish to thank Cotton Research Development Corporation (CRDC) Australia for funding the study and Southern Cross Plant Science, Southern Cross University and New South Wales DPI Agriculture for providing the academic environment to prepare this review.  
The authors declare that there are no conflicts of interest. Furthermore, the funding sponsors had a role in the decision to publish this review.