Structural elucidation of daphniacetal A, a new oxa-cage compound isolated from Daphniphyllum macropodum Miq

Natural product sciences: an integrative approach to the innovations of plant natural products

The study on plant natural products not only helps us understand that their structural diversity is the inevitable result of plant species diversity, but also helps us understand certain rules and unity of the inevitable connection between the two. The diversity and complexity of chemical structures of many natural products are beyond imagination before we elucidated their structures. The question that follows is what is the biological significance of these natural products. Intrigued by the relationship between plant resources, natural products and biological functions, the Hao laboratory has taken an integrative approach that employs tools and knowledge from multi-disciplines, including natural product chemistry, chemical ecology and chemical biology, to unveil the effects of plant natural products on plant resistance to diseases, and environmental acclimations. Collaborating with cell biologists, the research has resulted in discovery of new mechanisms of cellular signaling and lead compounds.

An Explorer of Chemical Biology of Plant Natural Products in Southwest China, Xiaojiang Hao

Xiaojiang Hao, who obtained Master Degree from Kunming Institute of Botany (KIB), Chinese Academy of Sciences (CAS) in 1985, and Doctor in Pharmacy degree in Pharmacy from Institute for Chemical Research, Kyoto University, in 1990, was born in Chongqing in July, 1951. In 1991, he returned to KIB, CAS, as an Associate professor and served as the chair of the Department of Phytochemistry. In 1994, he was promoted to a full professor at the current institute. He served as the Deputy Director of KIB and the Director of Open Laboratory of Phytochemistry from 1995 to 1997, and the Director of KIB from 1997 to 2005. Professor Hao has published more than 450 peer-reviewed SCI papers, which have been cited over 6000 times. He has obtained one PCT patent and 23 patents in China. Due to his tremendous efforts, one candidate drug, phenchlobenpyrrone, has entered the Phase II clinical trail for the treatment of Alzheimer's disease. Moreover, he won the First Prize of Natural Sciences in Yunnan Province for three times, and Ho Leung Ho Lee Fund Science and Technology Innovation Award in 2017.

Structural elucidation of dioxa-cage compounds from tetrahydroisobenzofuran-1(3H)-one: analysis of NMR data and GIAO chemical shifts calculations

The polycyclic compounds, especially the dioxa-cages, have attracted considerable attention in recent years. In our work, a series of 9β-substituted 3-oxo-4,11-dioxatetracyclo[5.2.1.1^5,8 .0^2,6 ]undecane compounds were unexpectedly isolated during bromination, chlorination and epoxidation reactions of the 3-hydroxy-3a,4,7,7a-tetrahydro-4,7-methanoisobenzofuran-1(3H)-one. After careful analysis of the NMR data, the chemical shifts of the isolated and the expected products were predicted by theoretical calculations using density functional theory and gauge including atomic orbitals. The best correlation between calculated and experimental data was evaluated by comparing mean absolute errors and applying DP4 probability methodology. Results from both approaches indicated a correct structural elucidation. Copyright © 2016 John Wiley & Sons, Ltd.

Daphmacromines A-J, alkaloids from Daphniphyllum macropodum

Ten new yuzurine-type Daphniphyllum alkaloids, daphmacromines A-J (1-10), along with seven known alkaloids were isolated from the leaves and stems of Daphniphyllum macropodum. Their structures were elucidated by extensive spectroscopic techniques, including 2D NMR spectroscopy and mass spectrometry, and the structure of 1 was confirmed by single-crystal X-ray diffraction. The pesticidal and cytotoxic activities of the isolated alkaloids were evaluated in vitro against brine shrimp (Artemia salina) and five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480), respectively. This study also suggested structural revisions of oxodaphnigracine, oxodaphnigraciline, and epioxodaphnigraciline.

Recent advances in enantioselective organocatalyzed anhydride desymmetrization and its application to the synthesis of valuable enantiopure compounds

Recent years have witnessed increasing interest in the field of asymmetric organocatalysis. In particular, efforts in this field have been devoted to the use of small organic molecules in asymmetric processes based on enantiotopic face discrimination and, only recently, efforts have also been devoted to asymmetric organocatalytic desymmetrization of prochiral substrates-a process based on enantiotopic group discrimination. This critical review documents the advances in the use of organocatalysis for the enantioselective desymmetrization of achiral and meso anhydrides and its application to the synthesis of valuable compounds as reported until 2010 (134 references).

Daphhimalenine A, a new alkaloid with an unprecedented skeleton, from Daphniphyllum himalense

Daphhimalenine A (1), a novel alkaloid with a rearrangement C-21 skeleton, containing a unique 1-azabicyclo[5.2.1]decane ring system, was isolated from the leaves of Daphniphyllum himalense, along with biogenetically related alkaloids daphhimalenine B (2) and daphnezomine T. Their structures were established on the basis of spectroscopic data, and the absolute configuration of 1 was assigned by computational methods. A plausible biosynthetic pathway of 1 was also proposed.

Dapholdhamines A-D, alkaloids from Daphniphyllum oldhami

Four new Daphniphyllum alkaloids, dapholdhamines A-D (1-4), were isolated from the leaves of Daphniphyllum oldhami. The structures and relative configurations of 1-4 were elucidated on the basis of spectroscopic data.