Kawahata, T., Otake, T., Mori, H., Kojima, Y., Oishi, I., Oka, S., Fukumori, Y. and Sano, K. : A novel substance purified from Perilla frutescens Britton inhibits early stage of HIV-1 replication without blocking viral adsorption. Antivir. Chemistr. Chemother. 13 : 283-288, 2003