38222-13-8

Upstream product

• 517-89-5 shikonin 
• 108-24-7 acetic anhydride 
• 64-19-7 acetic acid 
• 88818-36-4 5,8-diacetoxy-2-(1-acetoxy-4-methyl-3-pentenyl)-1,4-naphthoquinone 
• 145668-27-5 6-(1'-hydroxy-4'-methylpent-3'-en-1'-yl)-5,8-dimethoxy-1,4-naphthoquinone acetate 
• 171115-40-5 2(1'-hydroxy-4'-methylpent-3'-en-1'-yl)-1,4,5,8-tetramethoxynaphthalene acetate 

Downstream Products

• 80186-91-0 2-(5',5'-dimethyl-2'-tetrahydrofuranyl)-1,4,5,8-tetraacetoxynapthalene 
• 517-89-5 shikonin 
• 162283-70-7 propionylshikonin 
• 52387-14-1 isovalerylshikonin 

Relevant academic research and scientific papers

An improved and practical synthesis route to antiproliferative (±)-shikonin and its O-acyl derivatives

Shikonin and its O-acyl derivatives are attracting increasing levels of attention among medicinal chemists due to their potencies as highly selective cytotoxic agents against cancer cells. However, providing a large number of shikonin-related samples by organic synthesis remains challenging. In the present study, we developed an improved and practical synthesis route to shikonin derivatives by olefin metathesis that has enabled the gram-scale preparation of a prenylated tetramethylnaphthazaline, a key intermediate in the synthesis of shikonin. In addition, a method for the selective cleavage of the acyl protecting groups at the phenolic positions of tri-O-acylated shikonins has been developed that provides concise routes to diverse O-acylshikonin derivatives.

Design and synthesis of fluoroacylshikonin as an anticancer agent

A series of shikonin derivatives, selectively acylated by various fluorinated carboxylic acids at the side chain of shikonin, were synthesized and their anticancer activity evaluated, in which eight compounds are reported for the first time. Among all the compounds tested, compound S7 showed the most potent anticancer activity against B16-F10 (malignant melanoma cells), MG63 (human osteosarcoma cells), and A549 (lung cancer cells) with IC50 0.39 ± 0.01, 0.72 ± 0.04 and 0.58 ± 0.02 μmol/L. Docking simulation of compound S7 was carried out to position S7 into a tubulin active site to determine the probable binding conformation. All the results suggested that compound S7 may be a potential anticancer agent. Chirality 25:757-762, 2013. 2013 Wiley Periodicals, Inc. Copyright

Antimicrobial activities of naphthazarins from Arnebia euchroma

Bioassay-directed fractionation of extract of Arnebia euchroma led to the isolation of alkannin (1), shikonin (2), and their derivatives (3-8) as the active principles against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The stereochemistry of α-methylbutyryl alkannin (8) is revealed for the first time, and the antimicrobial activity of 8 was compared with its corresponding diastereomer (9). The derivatives 3-9 showed stronger anti-MRSA activity [minimum inhibitory concentrations (MICs) ranged from 1.56 to 3.13 μg/mL] than alkannin or shikonin (MIC = 6.25 μg/mL). Anti-MRSA activity of derivatives was bactericidal with minimum bactericidal concentration (MBC)/ MIC ≤ 2. In a time-kill assay, the bactericidal activity against MRSA was achieved as rapidly as 2 h. The derivatives 3-9 were also active against vancomycin-resistant Enterococcus faecium (F935) and vancomycin-resistant Enterococcus faecalis (CKU-17) with MICs similar to those with MRSA. Aromatic ester derivatives were also synthesized for antimicrobial activity comparison. None of these compounds were active against Gram-negative bacteria tested. Their cytotoxicity was also evaluated on selected cancer cell lines, and they expressed their activity in the range 0.6-5.4 μg/mL (CD50). Our results indicate that the ester derivatives of alkannin are potential candidates of anti-MRSA and anti-VRE agents with antitumor activity.

Acylshikonin analogues: Synthesis and inhibition of DNA topoisomerase-I

Compounds bearing an acyl group of a various size at 1'-OH of shikonin were synthesized as acyl analogues of shikonin, which was isolated from the root of Lithospermum erythrorhizon, and evaluated for inhibitory effect on topoisomerase-I activity. A selec

FORMATION OF STEREOISOMERIC MIXTURES OF NAPHTHOQUINONE DERIVATIVES IN ECHIUM LYCOPSIS CALLUS CULTURES

Callus cultures of Echium lycopsis were shown to produce a large amount of a mixture of red pigments consisting of five esterified derivatives of 5,8-dihydroxy-2-(1-hydroxy-4-methyl-3-pentenyl)-1,4-naphthoquinone.Examination of the absolute configuration of these compounds revealed that the cultures produced both the R-form (shikonin) and the S-form (alkannin) in various ratios depending upon the esterified derivative, although the overall ratio for the total derivatives was ca 1:1.On the other hand, all the corresponding derivatives produced by Lithospermum cultures were primarily of the R-form.It was also demonstrated that pigment formation in Echium cultures was inhibited by either white or blue light as well as by the synthetic auxin 2,4-D as in the case of Lithospermum cultures. Key Word Index - Echium lycopsis; Lithospermum erythrorhizon; Boraginaceae; callus cultures; biosynthesis; shikonin; alkannin; naphthoquinone pigments; stereoisomers.