It is with great respect and admiration to present this special issue of the Journal of Asian Natural Products Research, in honor of my mentor, Professor De-Quan Yu, for his outstanding contribution to the field of natural products chemistry. His former students, collaborators, and colleagues have contributed high-quality manuscripts for this special issue.
Prof. Yu was born and raised in Yantai, Shandong, China. After receiving his bachelor’s degree in Beijing Medical College (now Peking University Health Science Center) in 1956, he joined the Institute of Materia Medica (IMM), Chinese Academy of Medical Sciences & Peking Union Medical College, where he worked until December 2022. From January 1980 to August 1981, he was a visiting scholar at the National Center of Scientific Research (Centre National de la Recherche Scientifique or CNRS), which is the largest governmental research organization in France and the largest fundamental science agency in Europe. He was promoted to associate professor in 1982 and to professor in 1985 by IMM.
Over the past 60 years, Prof. Yu has dedicated to find new therapeutics from natural products, with a particular focus on studies of traditional Chinese medicines (TCMs), in hopes of finding solutions to critical human health issues. In China, he is well known for his success in the development of artificial musk. Musk is listed as a premium medicinal herb in the Sheng Nong’s Herbal Classic, and since ancient times, the source of musk has relied entirely on hunting musk deer, which resulted in the severe devastation of wild resources. Currently, musk deer has become the national first-class protected animals, and the hunting is strictly prohibited. In order to protect natural resource of musk deer, Prof. Yu was selected as the chief researcher, and collaborated with the experts in related fields to carry out the national research project "Artificial Musk" in 1975. Based on the systematic investigation of the chemical composition and the biological activity of natural musk, Yu’s group creatively proposed the formulation of "artificial musk," and made the main active ingredient alanine. Clinical double-blind controlled trials showed that the therapeutic efficacy and toxicity of the artificial musk groups were basically identical to those of the natural ones. The Ministry of Health, PRC approved artificial musk can be used equally with natural musk. Since the production of artificial musk, the cumulative sales have exceeded 229 tons, and achieved great social and economic benefits. More importantly, the successful development and promotion of artificial musk equals rescuing and protecting 66 million male musk deer, with significant ecological benefits. The project won the first prize of the National Science and Technology Progress Award.
Throughout Prof. Yu’s career, he has been engaged in the discovery and development of new drugs from natural products as well as the structure modification of semi-synthetic or fully synthetic natural compounds. He has found hundreds of novel compounds from traditional Chinese medicines or Chinese herbs, most of which have unique structures and prominent bioactivities, including antioxidant, anti-inflammatory, anti-cancer, anti-senile dementia, and hepatic-protective effects. One typical example is the discovery of new anti-malarial agents. Malaria is a serious epidemic that poses a threat to human health. Professor Yu was responsible for identifying anti-malaria compounds from natural products. Based on the literature review, small-scale preliminary trials and activity screening, Radix Dichroae (Changshan in Chinese, with active ingredients dichroines A and B) was identified as the candidate, which was found to possess a killing effect on malaria parasites in the blood after clinical experiments. However, patients would suffer from severe vomiting that could not be stopped by ordinary therapy after taking the agent. Through repeated experiments and studies, it was found that the anti-malaria effect of Changshan is inseparable from vomiting. After screening countless natural products, his team eventually found an effective anti-malaria herb, i.e. the roots of Artabotrys hexapetalus. They were surprised to find that the anti-malarial effect of root extract of A. hexapetalus was similar to that of the synthetic anti-malarial drug chloroquine. After thought and discussion, they concluded that some enzymes in the dried roots still remained active and continued to catalyze the original secondary metabolites to form compounds with anti-malaria activity. Fortunately, he isolated the active ingredient yingzhaosu A from the root extracts, which had a significant anti-malarial effect, as confirmed by the treatment of several newly-diagnosed malaria patients. Subsequently, the structures of yingzhaosus A and B were characterized, in which the peroxide bond of yingzhaosu A was first reported as the anti-malarial active group. Yu’s team was awarded the "Collective Award for Significant Contributions" by four national ministries and commissions.
With the rapid development of modern spectroscopic technology, especially the maturity and common use of 2D NMR, the structural information of milligram scale of samples could be obtained, presenting significant advantages in determining chemical structures, especially the complicated structures of natural products. Prof. Yu closely followed the development of international spectroscopy, introduced the latest technology promptly, pioneered to use modern 2D NMR technology to study the chemical structure of natural products in China, and published relevant papers and monographs. He summarized the UV characteristics of various types of natural products, concluded the structure-spectra relationships of certain natural products based on 1H NMR and 13C NMR, simplified the signal assignment methods for AB and ABX systems in 1H NMR spectrum, and found that 11-carbonyl and 13-carbonyl of diterpenoid alkaloids exhibited different Cotton effects, thereby resolving the structural issues long debated in the literature. As the chief editor, he wrote UV Spectrum of Application in Organic Chemistry and The Analysis of NMR Spectroscopy, translated Structure Elucidation by Modern NMR, and published a number of papers related to spectroscopy. Among them, The Analysis of NMR Spectroscopy won the first prize of the Excellent Book Award by the Ministry of Chemical Industry in 2000. Over 60 years of selfless dedication, Prof. Yu won widespread acclaim and respect.
Prof. Yu has been an Academician of Chinese Academy of Engineering since 1999, and still served as the distinguished senior professor in the Institute of Materia Medica. He has supervised more than 80 graduate students and postdoctoral fellows, some of whom are now prominent scientists in many universities and institutions. In his old age, Prof. Yu persisted in scientific research, and from setting up “the Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education” to further establishing "the State Key Laboratory of Bioactive Substance and Function of Natural Medicines," he played a key role as Director of the former and Honorary Director of the Academic Committee of the latter.
The dedication of Prof. Yu to the natural products field was also reflected in many positions he held in a number of organizations, as well as honors and awards he received. He has served as Director of the Chinese Chemical Society and Vice Chairman of Division of Organic Chemistry of Chinese Chemical Society; a senior member of Medicine and Health Engineering Division, Chinese Academy of Engineering; Deputy Director of the Academic Committee for State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences; a member of the Academic Committee for the State Key Laboratory of Natural and Biomimetic Drugs, Peking University; a Pharmaceutical Expert Advisory Committee member of the Ministry of Health; an Academic Advisory Committee member of Chinese Academy of Medical Sciences. He has also been a member of American Chemical Society (ACS), American Society of Pharmacognosy (ASP), and American Association for the Advancement of Science (AAAS). Prof. Yu received many honors and awards, such as “Qiushi” Annual Award for Scientific Achievement (2001), the Special Contribution Award of Pharmaceutical Science Development Prize (2009), and a lifetime achievement award of Chinese Academy of Medical Sciences & Peking Union Medical College (2016).
He has published or co-authored over 300 articles, book chapters, and reviews, applied 12 patents and edited 6 books. In 2007, Advances in Natural Product Chemistry edited by him and professor Yu-Lin Wu, as one of the Book Series of Advances in Chemistry, won the 2007 Excellent Publication Award of Chinese Petroleum and Chemical Industry (Book Award, the first prize). In 1998, he and Professor Xiao-Tian Liang founded an international English journal – Journal of Asian Natural Products Research, and had worked for the journal for about 25 years as associate Editor-in-Chief and Editor-in-Chief. Moreover, he served as Associate Editor of Acta Pharmaceutica Sinica B, and an Editorial Advisory Board member of Planta Medica.
In closing, we wish to acknowledge Prof. Hui-Lan Zhang, Yu’s wife, who has accompanied him for more than 60 years, as his great support.