1. Li JWH, Vederas JC. Drug discovery and natural products: end of an era or an endless frontier? Sci. 2009; 325:161–5.

2. Harvey AL. Natural products in drug discovery. Drug Discov Today. 2008;13:894–901.

3. Bensaddek L, Villarreal ML and Fliniaux MA. Induction and Growth of Hairy Roots for the Production of Medicinal Compounds. Electronic J. Integrative Bio Sci.2008;1:2-9.

4. Julsing KM, Quax WJ and Kayser O. The Engineering of Medicinal Plants: Prospects and Limitations of Medicinal Plant Biotechnology. Medicinal Plant Biotechnology.Wiley-VCH Verlag GmbH. 2008;1-8.

5. Cragg GM and Newman DJ. Plants as Source of Anticancer Agents. J Ethnophar., 2005; 100: 72-79.

6. Oliveira I, Valentão P, Lopes R, Andrade PB, Bento A and Pereira JA.“Phytochemical characterization and radical scavenging activity of Portulaca oleraceae L. leaves and stems,” Microchem J, 2009; 92:129–134.

7. Dweck AC. Purslane (Portulaca oleracea)-the global panacea".Personal Care Magazine. 2001;2:7-15.

8. Zhang C, Yan Q, Cheuk WK and Wu J. Enhancement of tanshinone production in Salvia miltiorrhiza hairy root culture by Ag+ elicitation and nutrient feeding. Planta Medica. 2004;70:147-151.

9. Akhonzadeh S. Encyclopedia of Iranian Medicinal Plants. Arjomand Press: Tehran, Iran. (in Persian). 2000.

10. El-Sayed MIK. Effects of Portulaca oleracea L. seeds in treatment of type-2 diabetes mellitus patients as adjunctive and alternative therapy. J Ethnopharmacol. 2011;137:643-651.

11. Moghadam YA, Piri KH, Bahramnejad B and Habibi P. Methyl Jasmonate and Salicylic acid effects on the dopamine production in hairy cultures of Portulaca oleracea (purslan). Bull. Env. Pharmacol. Life Sci.  2013;2: 89-94

12. Chen J, Shi YP and Liu JY. Determination of noradrenaline and dopamine in Chinese herbal extracts from Portulaca oleracea L. by high-performance liquid chromatography". J Chromatogr A. 2003;1003:127-132.

13. Daviesa KM and Espley RV. Opportunities and challenges for metabolic engineering of secondary metabolite pathways for improved human health characters in fruit and vegetable crops. New Zealand J Crop Hortic Sci. 2013;41:154-177.

14. Bhayat SI, Gowda HM, Eisenhut M. Should dopamine be the first line inotrope in the treatment of neonatal hypotension? Review of the evidence. World J Clinical Pediatrics. 2016;5:212–22.

15. Zhang K and Ni Y. Tyrosine decarboxylase from Lactobacillus brevis: soluble expression and characterization. Protein Expres. Purif. 2014;94:33–39.

16. Murashig T and Skoog F. a revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue Cultures. Physiology plantarum. 1962; 15.

17. Saify Nabiabad H, Yaghoobi MM, Jalali M and Hosseinkhani S. Expression Analysis and purification of human recombinant tissue type plasminogen activator (rt-PA) from transgenic tobacco plants. Prep Biochem Biotechnol. 2011;41:2:175-186

18. Babashpour S, Aminzadeh S, Farrokhi N, Karkhane A, Haghbeen K. Characterization of a chitinase (Chit62) from Serratia marcescens B4A and its efficacy as a bioshield against plant fungal pathogens. Biochemical Genetics. 2012; 50:722-735

19. Stephen Stoker H. Organic and Biological Chemistry. Cengage Learning. 2015; p. 371. ISBN 978-1-305-68645-

20. Haynie DT, Xue B. Superdomain in the protein structure hierarchy: the case of PTP-C2. Protein Sci. 2015;24: 874-82.

21. Allison R, Robert C, Christodoulou C, Vendruscolo M and Dobson M. A relationship between the transient structure in the monomeric state and the aggregation propensities of α-synuclein and β-synuclein. Biochem. 2014;53:7170–7183.

22. Shirazi Z, Piri Kh., Mirzaie Asl A. and Hasanloo T. Glycyrrhizin and Isoliquiritigenin Production by Hairy Root Culture of Glycyrriz glabra. J Med Plants Res. 2012; 31: 4640-4646.

23. De Backer D, Aldecoa C, Njimi H, Vincent JL.Dopamine versus norepinephrine in the treatment of septic shock: a meta-analysis. Critical Care Medicine. 2012; 40:725–30.

24. Ahmadi Moghadam Y, Piri Kh, Bahramnejad B, Ghiasvand T. Dopamine Production in Hairy Root Cultures of Portulaca oleracea (Purslane) Using Agrobacterium rhizogenes. J Agr Sci Tech. 2014;16: 409-420.