Phytochemical and genetic analyses of ancient cannabis from Central Asia
Ethan B. Russo, Hong-En Jiang, Xiao Li, Alan Sutton, Andrea Carboni, Francesca del Bianco, Giuseppe Mandolino, David J. Potter, You-Xing Zhao, Subir Bera, Yong-Bing Zhang, En Guo Lu, David K. Ferguson, Francis Hueber, Liang-Cheng Zhao, Chang-Jiang Liu, Yu-Fei Wang and Cheng-Sen Li
Journal of Experimental Botany, 2008, Vol. 59, No. 15, pp. 4171–4182,
The Yanghai Tombs near Turpan, Xinjiang-Uighur Autonomous Region, China have recently been excavated to reveal the 2700-year-old grave of a Caucasoid shaman whose accoutrements included a large cache of cannabis, superbly preserved by climatic and burial conditions. A multidisciplinary international team demonstrated through botanical examination, phytochemical investigation, and genetic deoxyribonucleic acid analysis by polymerase chain reaction that this material contained tetrahydrocannabinol, the psychoactive component of cannabis, its oxidative degradation product, cannabinol, other metabolites, and its synthetic enzyme, tetrahydrocannabinolic acid synthase, as well as a novel genetic variant with two single nucleotide polymorphisms. The cannabis was presumably employed by this culture as a medicinal or psychoactive agent, or an aid to divination. To our knowledge, these investigations provide the oldest documentation of cannabis as a pharmacologically active agent, and contribute to the medical and archaeological record of this pre-Silk Road culture.
Key words : Archaeology, botany, cannabis, cannabinoids, archaeobotany, ethnopharmacology, genetics, medical history, phytochemistry.
Uighur farmers cultivating the land at the base of the Huoyan Shan (‘Flaming Mountains’) in the Gobi Desert near Turpan, Xinjiang-Uighur Autonomous Region, China some 20 years ago uncovered a vast ancient cemetery (54 000 m2) that seemingly corresponds to the nearby Aidinghu, Alagou, and Subeixi excavations (Ma and Wang, 1994; Chen and Hiebert, 1995; Davis-Kimball, 1998; Kamberi, 1998; An, 2008) (see Supplementary Fig. S1 at JXB online) attributed to the Gushı culture (later rendered Ju¨shi, or Cheshi) (Academia Turfanica, 2006). The first written reports concerning this clan, drafted about 2000 years BP (before present) in the Chinese historical record, Hou Hanshu, described nomadic light haired blue-eyed Caucasians speaking an Indo-European language (probably a form of Tocharian, an extinct Indo-European tongue related to Celtic, Italic, and Anatolic (Ma and Sun, 1994). The Gushı tended horses and grazing animals, farmed the land and were accomplished archers (Mallory and Mair, 2000). The site is centrally located in the Eurasian landmass (Fig. 1A, B), 2500 km from any ocean and located in the Ayding Lake basin, the second lowest spot on Earth after the Dead Sea (Fig. 1A, B). Formal excavations completed in 2003 revealed some 2500 tombs dating from 3200–2000 years BP (Xinjiang Institute of Cultural Relics and Archaeology, 2004). Other evidence from chipped stone tools and other items indicate a possible human presence in the area for some 10 000–40 000 years (Kamberi, 1998; Academia Turfanica, 2006). Due to a combination of deep graves (2 m or more), an extremely arid climate (16 mm annual rainfall), and alkaline soil conditions (pH 8.6–9.1 (Pan, 1996), the remarkable preservation of the human remains resulted in the mummification of many bodies without a need for chemical methods. Numerous artefacts from the tombs included equestrian equipment and numerous Western Asian crops such as Capparis spinosa L. (capers) (Jiang et al., 2007), Triticum spp. (wheat), Hordeum spp. (naked barley), and Vitis vinifera L. (grapevines) (Jiang, 2008), often centuries before their first descriptions in Eastern China (Puett, 1998).