Enhanced synthesis of andrographolide by Aspergillus niger and Penicillium expansum elicitors in cell suspension culture of Andrographis paniculata (Burm. f.) Nees

黑曲霉和扩展青霉诱导子可增强穿心莲（Andrographis paniculata (Burm. f.) Nees）细胞悬浮培养物中穿心莲内酯的合成