Gossypolhemiquinone, a dimeric sesquiterpenoid identified in cotton (Gossypium) Author Stipanovic, Robert USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author Puckhaber, Lorraine USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author Jr., James Frelichowski USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author Esquivel, Jesus USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author Westbrook, John USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author O’Neil, Mike USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author Bell, Alois USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States Author Dowd, Michael USDA, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA 70124, United States Author Hake, Kater Cotton Incorporated, 6399 Weston Parkway, Cary, NC 27513, United States Author Duke, Sara USDA, Agricultural Research Service, Southern Plains Agricultural Research Center, College Station, TX 77845, United States text Phytochemistry 2016 2016-02-29 122 165 171 http://dx.doi.org/10.1016/j.phytochem.2015.12.009 journal article 285319 10.1016/j.phytochem.2015.12.009 5b997348-5f35-4147-812e-77402b84742b 1873-3700 10485477 2.3. GHQ ( 9 ) and gossypol ( 1 ) in the D genome of Gossypium and in commercial cottons G. thurberi is a member of the D genome of Gossypium . In a previous investigation of terpenoids in the young leaves of G. thurberi using TLC plates, only gossypol ( 1 ) was identified in this tissue ( Stipanovic et al., 1977 ). Thus, terpenoids such as the sesquiterpenoid hemigossypolone ( 7 ) and the sesterterpenoids heliocides H 1 , H 2 , H 3 and H 4 ( 3–6 ) ( Fig. 1 ) that are found in commercial Upland cottons ( Gossypium hirsutum ), as well as other members of Gossypium , were not found. To extend this investigation, several Gossypium accessions of the D genome available in the USDA Cotton Germplasm collection were grown in the greenhouse; leaves were collected, freeze dried, and ground. The ground tissue was extracted and immediately subjected to HPLC analysis; the results are shown in Table 3 . As found previously, other sesquiterpenoids and sesterterpenoids normally in G. hirsutum were not detected in G. thurberi nor in most other members of the D genome. However, GHQ ( 9 ) was present in small amounts in these cottons. As previously reported ( Stipanovic et al., 1977 ), within the D genome only the leaves of Gossypium gossypioides (Ulbrich) contained hemigossypolone ( 7 ) and heliocides ( 3–6 ); the leaves of other members of the D genome did not contain these terpenoids. In addition, the leaves of G. raimondii contained only gossypol ( 1 ) and the sesquiterpenoid, raimondal ( 8 ) ( Fig. 1 ). Four commercial cultivars of G. hirsutum cotton also were analyzed ( Table 4 ). GHQ ( 9 ) was not detected in these plants, but, as expected, gossypol ( 1 ), hemigossypolone ( 7 ) and heliocides H 1 – H 4 ( 3–6 ) were detected.