Somogyi Múzeumok Közleményei 18. (Kaposvár, 2008)

CSAPÓ JÁNOS, ALBERT CSILLA, SALAMON SZIDÓNIA, DARVAS LÓRÁNT, KOVÁCS JÁNOS, SALAMON ROZÁLIA, ALBERT BEÁTA & CSAPÓNÉ KISS ZSUZSANNA: AZ aminosavak racemizációján alapuló korbecslés alkalmazása egy magyarországi és egy erdélyi mamutcsont és -agyar korának meghatározására

Somogyi Múzeumok Közleményei 18:139-146 Kaposvár, 2008 Az aminosavak racemizációján alapuló korbecslés alkalmazása egy magyarországi és egy erdélyi mamutcsont és -agyar korának meghatározására 12 CSAPÓ JÁNOS, 1 ALBERT CSILLA, 1 SALAMON SZIDÓNIA,

3 DARVAS LÓRÁNT, 4 KOVÁCS JÁNOS, 1 SALAMON ROZÁLIA, 1 ALBERT BEÁTA & 2 CSAPÓNÉ KISS ZSUZSANNA 1

Sapientia Hungarian University of Transylvania, Campus of Csíkszereda 530104 Csíkszereda, Szabadság tér 1., Romania, e-mail: albertcsilla@sapientia.siculorum.ro; ww.emte.ro 2

University of Kaposvár, Faculty of Animal Science, Institute of Chemistry, Department of Biochemistry and Food Chemistry H-7400 Kaposvár, Guba S. u. 40., Hungary, e-mail: csapo@ke.hu; www.atk.u-kaposvar.hu 3

Csíki Székely Museum, Csíkszereda, Decemberi Forradalom u. 34., Romania "University of Pécs, Faculty of Natural Science, Department of Geology, H-7633 Pécs, Ifjúság u. 6., Hungary CSAPÓ, J., ALBERT, CS., SALAMON, SZ., DARVAS, L., KOVÁCS, J., SALAMON, R., ALBERT B. & CSAPÓNÉ KISS, ZS.: Use of amino acid racemization for age determination of two mammoth's tusk and bone from Hungarian and Transylvanian regions. Abstract: After developing protein hydrolysis method with low racemization, a method has been developed to determine the age of fossil bone samples based on amino acid racemization (AAR). Approximately one hundred fossil bone samples of known age from Hungary were collected and analysed for D- and L-amino acids. As the racemization of amino acids is affected by temperature, pH, metal content of the soil, and time passed since death, these factors were eliminated by comparing the estimated age to age determined by the radiocarbon method. Determining the D- and L-amino acid contents in samples of known age, determining the half life of racemization and plotting the D/L ratio as a function of time, calibration curves were obtained. These curves can be used for the age estimation of samples after determining their D- and L-amino acid content. The D/L ratio for 2 to 3 amino acids was determined for each sample and the mean value of estimated ages based on calibration curves was considered to estimate age of the fossil samples. After developing the age determination method, we have determined the age of woolly mammoth (Mammuthus primigenius) remains found near Pécs in Hungary, and near Csíkszereda in Transylvania by a method based on amino acid racemization (AAR). The mammoth skeletal remnants were found in fine-grained yellow, clayey loess of late glacial aeolian origin. Calibration curves - D- and L-amino acid ratios of bones of known age determined by radiocarbon method as a function of age - earlier used for age determination of human bones, was employed in case of the mammoth tusk (Csíkszereda), and mammoth tusk as well as mammoth cranial-bone (Pécs). As the racemization of the amino acids is considerably affected by the pH and heavy metal concentration of the environment, therefore we examined the composition and micro element concentration of the soil. It was established that the pH of the loess (7.14 Csíkszereda; 7.77 Pécs) did not affect substantially the racemization of the amino acids, therefore the AAR method is suitable for determination of age of these samples. D-allolle contents of the samples were measured by INGOS AAA 400 amino acid analyzer, using postcolumn derivatization with ninhydrin, while D- and L-Asp, -Glu and -Ala contents were measured by MERCK Hitachi LaChrom high performance liquid Chromatograph using precolumn derivatization with OPA/TATG. Crude protein contents of mammoth tusk from Csíkszereda were measured to be 11.7%, whereas those of mammoth tusk from Pécs were measured to be only 1.13%, and those of cranial-bone from Pécs to be 8.17%. From these results the conclusion can be drawn that mammoth tusk from Csíkszereda has been preserved better. In the course of our examinations it was established that the sample practically did not contain D-allo-lle, thus this amino acid cannot be used for the age estimation. In the D-amino acids it was established that for Glu and Ala the D/L ratios were below 0.1, therefore based on our earlier results we could not use these data in age determination. The amount of D-Asp was appropriate, nearly optimal in all three samples. Based on the D/L-Asp ratio of the mammoth tusk from Csíkszereda measured to be 0.229, using our calibration curve we could estimate the age of the tusk to be 9460±470 years. D/L-Asp ratio of the mammoth tusk from Pécs was measured to be 0.247, while that of the cranial-bone to be 0.241, thus based on the tusk the age could be estimated to be 10200±500 years, based on the cranial-bone to be 9960±500 years. The difference between the tusk and the bone is 240 years, which is within the error limit of the method. Keywords: wooly mammoth, tusk, bone, amino acids, ion exchange column chromatography, IEC, high performance column chromatography, HPLC, analytical methods, age determination, racemization of amino acids. Bevezetés Korábban (CSAPÓ és mtsai 1994, 1997, 1998, 2004; ALBERT és mtsai 2006) az izoleucin epimerizációját és a többi fehérjealkotó aminosav recamizációját felhasználva módszert dolgoztunk ki fossziliák korának meghatározására. Az általunk kidolgozott, aminosav racemizáción, illetve epimerizáción alapuló kormeghatározási módszer egy olyan vizsgálat, melyet Magyarországon és Romániában - tudomásunk szerint - még senki sem alkalmazott, a fehérjealkotó aminosavak többségét pedig mi használtuk fel elsőként a világon - csoportosan - kormeghatározásra. A D-allo-izoleucin és a „lassú" racemizációs idejű aminosavakkal a 100.000-450.000 év közti fehérjetartalmú régészeti leletek, a „gyors" és „közepes" racemizációs idejű aminosavak segítségével