Chemical approaches for the stereocontrolled synthesis of 1,2-cis-β-D-rhamnosides / 中国天然药物

In carbohydrate chemistry, the stereoselective synthesis of 1,2-cis-glycosides remains a formidable challenge. This complexity is comparable to the synthesis of 1,2-cis-β-D-mannosides, primarily due to the adverse anomeric and Δ-2 effects. Over the past decades, to attain β-stereoselectivity in D-rhamnosylation, researchers have devised numerous direct and indirect methodologies, including the hydrogen-bond-mediated aglycone delivery (HAD) method, the synthesis of β-D-mannoside paired with C6 deoxygenation, and the combined approach of 1,2-trans-glycosylation and C2 epimerization. This review elaborates on the advancements in β-D-rhamnosylation and its implications for the total synthesis of tiacumicin B and other physiologically relevant glycans.

A new class of potent liver injury protective compounds: Structural elucidation, total synthesis and bioactivity study

A new class of potent liver injury protective compounds, phychetins A-D ( 1- 4) featuring an unique 6/6/5/6/5 pentacyclic framework, were isolated and structurally characterized from a Chinese medicinal plant Phyllanthus franchetianus. Compounds 2- 4 are three pairs of enantiomers that were initially obtained in a racemic manner, and were further separated by chiral HPLC preparation. Compounds 1- 4 were proposed to be originated biosynthetically from a coexisting lignan via an intramolecular Friedel-Crafts reaction as the key step. A bioinspired total synthesis strategy was thus designated, and allowed the effective syntheses of compounds 2- 4 in high yields. Some of compounds exhibited significant anti-inflammatory activities in vitro via suppressing the production of pro-inflammatory cytokine IL-1β. Notably, compound 4, the most active enantiomeric pair in vitro, displayed prominent potent protecting activity against liver injury at a low dose of 3 mg/kg in mice, which could serve as a promising lead for the development of acute liver injury therapeutic agent.

Synthesis of the active ingredient rosavin of Rhodiola rosea / 药学实践杂志

Objective To establish the chemical synthesis of the active ingredient rosavin of Rhodiola rosea. Methods β-D-pentaacetylglucose, 1-hydroxy-2,3,4-triacetylarabinose and cinnamyl alcohol were used as starting materials. The target compound was prepared by 1-position selective of β-D-pentaacetylglucose deacetylation, glycosylation reaction, glucose 6-OH selective protection and deprotection and other 8-step reactions. Results The target product, rosavage, was successfully obtained with high yield. The structure was confirmed by ESI-MS, 1H-NMR and 13C-NMR. The protection of 6-OH with high selectivity and high yield of tert-butyldiphenyl chlorosilane played a vital role in the synthesis process,. Conclusion The synthetic route has the advantages of simple operation, high yield, and good safety.

Synthetic progress towards natural products communesins / 国际药学研究杂志

Communesins are a class of alkaloids mainly from the marine-derived fungi belonging to the genus Penicillium. The communesins contain a unique, densely functional caged seven-ring system skeleton, with five stereogenic centers at least, of which two are the vicinal quaternary carbon centers. These structural features make the synthesis of these compounds extremely challenging. In addition, communesins have been known to have a variety of biological activities such as the insecticidal, cell proliferation inhibito ry and significant cytotoxic activities. At present, eight research groups have completed the total synthesis of several communesins, and reports on the skeleton synthesis have been published. This paper summarizes the chemical skeleton synthesis and total synthesis of communesins in a chronological order, so as to provide a reference for further studies on this class of natural compounds.

Advances in biosynthesis and chemical synthesis of phenylethanoid glycosides / 中草药

Phenylethanoid glycosides (PeGs) are natural active ingredients of many plants at home and abroad. They possess a spectrum of beneficial activities, such as anti-oxidant, hepatoprotective, whitening, and neuroprotective. However, the content of PeGs in food or medicinal materials is low and unstable. During the past decade, studies on biosynthesis and metabolic regulation of PeGs have been extensively carried out. Here, the recent achievements in biosynthesis and metabolic regulation of PeGs in plants and microorganisms are reviewed, as well as in total synthesis and semi-synthesis of PeGs. Hopefully, this work done so far will provide reference for elucidating the biosynthesis mechanism of PeGs, stabilizing and improving the content of PeGs in herbal materials, improving the quality, and synthesizing PeGs by microbial metabolic engineering or chemical synthesis.

Marine sponges of the genus as promising drug sources: chemical and biological aspects

Marine sponges of the genus are well known as rich sources of diverse and complex biologically relevant natural products, including alkaloids, terpenoids, peptides, lipids, and steroids. Some of these metabolites, with novel structures and promising biological activities, have attracted a lot of attention from chemists seeking to perform their total synthesis in parallel to intensive biological studies towards new drug leads. In this review, we summarized the distribution of the chemically investigated sponges, the isolation, synthesis and biological activities of their secondary metabolites, covering the literature from 1982 to early 2018.

Total synthesis of cyclodepsipeptide Hikiamides A-C / 中国药科大学学报

@#Total synthesis of cyclodepsipeptide Hikiamides A-C was described. Fragment convergent condensation method was applied for the preparation of Hikiamides A-C, starting from Commercially available amino acid such as L-N-Boc-Phe-OH, L-N-Boc-Trp-OH, L-N-Cbz-Van-OH etc. Tripeptide fragments(compounds 5a/5b)and dipeptide fragments(compounds 8a/8b)were first prepared. The subsequent condensation of the resulted two fragments provided protected linear pentapetides(compounds 9a/9b/9c); Finally, the linear pentapetide was cyclized by a mixed condensing agents comprised of PyBOP and HBTU. Hikiamides A-C was obtained with total yields of 9%, 11% and 6. 5%, respectively. Compared with the natural source, this method has the advantages of low cost, convenient operation and high yield, which effectively solves the problem of low isolated yield of Hikiamides A-C from Fusarium sp.

Advances in the synthesis of bromophenol compounds / 国际药学研究杂志

Bromophenols are a class of natural products featuring novel chemical structures and diverse biological activities. These compounds possess anti-tumor,antibacterial and anti-oxidation activities,which has attracted much attention from synthetic chemists. Bromophenol derivatives are synthesized using bromination,methylation,reduction and alkylation,while the total synthesis of complex bromophenol-type natural products make use of aldol reaction,Wittig reaction,reduction amination as well as Curtius rear- rangement. This review summarizes the synthesis of bromophenol derivatives and complex bromophenol-type natural products,to pro- vide reference for their efficient research.

Research progress on total synthesis and activity of nitidine / 药学实践杂志

Nitidine is a benzophenanthridine alkaloid derived from Zanthorulum nitidum (Roxb .) DC root .Research shows that nitidine displays rich biological activities ,such as anti-tumor ,anti-inflammatory ,anti-malaria and etc .This paper reviewed the progress of the total synthesis methods for nitidine and recent research on bioactivities .

Historical story on natural medicinal chemistry: The most preeminent natural organic chemist of 20th century-Robert Burns Woodward / 中草药

Robert Burns Woodward was a well-known natural organic chemist. This paper reviewed the work and his contribution to the development of natural product chemistry and total synthesis of natural products including spectroscopic methods such as UV, IR, and NMR, the Octant Rule, structure elucidation and total synthesis of natural products, theory study, biogenesis, et al. This is one of the series papers about historical story on natural medicinal chemistry, which was dedicated to Robert Burns Woodward on the occasion of his 100th birthday.

Total synthesis of sauropunol A-D isolated from Sauropus rostratus genus plants / 中国药科大学学报

Sauropunol A-D potentially with anti-inflammatory,anti-bacterial activities were recently isolated from traditional Chinese medicinal plant Sauropus rostratus.Herein,we report the total synthesis of sauropunol (A-D) starting from a commercially available 2-deoxy-D-arabino-hexopyranose.The trifluoromethane sulfonation of intermediates could simultaneously trigger intramolecular cyclization to afford 3,6-anhydro hexofuranoside scaffold.The following deprotection reaction could produce sauropunol A,B and C/D with total yields of 21％,5％,and 17％ (isomer sauropunol C/D),respectively.Structures of the target compounds were confirmed by comparison with NMR spectroscopic properties of those previously reported.

Total synthesis of the natural product of crinumaquine / 药学实践杂志

Objective To complete the synthesis of the natural product of crinumaquine .Methods 3 ,4-methylenedioxy-phenethylamine and 2 ,5-dimthoxyphenylacetic were taken as starting material ,and chemical reactions of condensation ,cycliza-tion ,reduction ,oxidation and other reactions were conducted .Results and Conclusion The optimum synthetic route was deter-minedunder which the final yield rate was 73% .

Historical story on natural medicinal chemistry: Vitamin B12 / 中草药

Vitamin B12, a water-soluble vitamin with a key role in maintaining normal function of the human body, was discovered in the late 1940s. The unique structure with a corrin-ligand of vitamin B12 was elucidated by X-ray crystallography, while its total synthesis was accomplished several years later. In this paper, the history of structural determination as well as the skeleton construction strategies of the total synthesis of vitamin B12 has been described.

Historical story on natural medicinal chemistry: Isolation, structure, and total synthesis of quinine / 中草药

Quinine is a very famous natural medicine that has saved millions of lives, even being believed to affect the development process of human beings. The study of quinine has left a very important record in the history of science. In this paper, the historical stories on the discovery and study of quinine are summarized in memory of the great discoveries and in honor of the scientists. It also aims at providing the references for future related research. This article is one of the series of historical stories on natural product chemistry written by the authors.

Progress in the chemical synthesis of artemisinin / 中国药学杂志

OBJECTIVE: To introduce the research progress in total-and semi-synthesis of artemisinin. METHODS: The review was based on representative literatures, and the data was summarized and analyzed. RESULTS AND CONCLUSION: Artemisinin is one of the most effective anti-malarial medicines. Since its discovery, artemisinin chemical synthesis has become a hot research topic. Nine total-synthesis methods andfive semi-synthesis methods were summarized, for which the overall yields were up to 10% and 60% respectively. Efficient synthesis of artemisinin in large scale by industry would be realized in the near future, and it will benefit hundred millions of patients.

Hypericin: chemical synthesis and biosynthesis / 中国天然药物

Hypericin is one of the most important phenanthoperylene quinones extracted mainly from plants of the genus Hypericum belonging to the sections Euhypericum and Campylosporus of Keller's classification. Widespread attention to the antiviral and anti-tumor properties of hypericin has spurred investigations of the chemical synthesis and biosynthesis of this unique compound. However, the synthetic strategies are challenging for organic and biological chemists. In this review, specific significant advances in total synthesis, semi-synthesis, and biosynthesis in the past decades are summarized.

Total synthesis of neokotalanol, a potent α-glucosidase inhibitor isolated from Salacia reticulata / 中国天然药物

Neokotalanol, a potent α-glucosidase inhibitor isolated from Salacia reticulata, was synthesized through a key coupling reaction between a perbenzylated thiosugar and an appropriately protected perseitol triflate derived from D-mannose. This key step was found to be quite temperature dependent, and a simultaneous cyclization of the triflate leading to a characteristic 2,4,7-trioxabicyclo[4.2.1]nonane system was detected.

SYNTHESIS OF SARMENTOSIN / 药学学报

AIM: The synthesis of sarmentosin. METHODS: Condensation of butane-1,2,4-triol-1,2-acetonide(3) with α-D-glucopyranosyl bromide tetraacetate in the presence of Ag2O and molecular sieves gave the desired β-glucoside 4,which was transformed into sarmentosin via a reaction sequence of 7 steps. RESULTS: The overall yield is 5.8%. CONCLUSION: The first synthesis of sarmentosin(1),a potent natural GPT lowering agent,was achieved.

Stereoselective total synthesis of some insect pheromones: (±)-serricornine and (±)-invictolide

An efficient (12 steps, 12% overallyield) and stereoselective total synthesis of (±)-serricornine (1) the sex pheromone of the cigarette beetle (Lasioderma serricornine F) is described. The preparation of intermediate 5, which encompasses the proper relative configuration of three contiguous chiral centers of (±)-invictolide, (3), is discussed.