Musellarin C

Chemical constituents from the aerial parts of Musella lasiocarpa.[Reference: WebLink]

Nat Prod Bioprospect. 2011 Aug; 1(1): 41–47.

METHODS AND RESULTS:
Phytochemical investigation of the aerial parts of the monotypic plant, Musella lasiocarpa, led to the isolation of four rare bicyclic diarylheptanoids, Musellarin B,Musellarin C, musellarin D, musellarin E (2–5), two new phenylphenalenones, 2-methoxy-9-(3′,4′-dihydroxyphenyl)-1Hphenalen-1-one (9), 2-methoxy-9-(3′-methoxy-4′-hydroxyphenyl)-1H-phenalen-1-one (10), a new acenaphtylene derivative, trans-(1S,2S)-3-(4′-methoxyphenyl)-acenaphthene-1,2-diol (13), and two new sucrose esters, 1,2′,3′,4′,6′-O-pentaacetyl-3-O-trans-pcoumaroylsucrose (16), 1,2′,3′,4′,6′-O-pentaacetyl-3-O-cis-p-coumaroylsucrose (17), together with nine known compounds. In addition, (4E,6E)-1-(3′,4′-dihydroxyphenyl)-7-(4″-hydroxyphenyl)-hepta-4,6-dien-3-one (15) was isolated for the first time from a natural source. The structures of new compounds were elucidated by analysis of their spectroscopic data.
CONCLUSIONS:
Compounds 2, 6, 8–10, 12, and 14 were cytotoxic toward several of the human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480). Of these, the new compound 9 was the most potent one, with IC50 values of 5.8, 10.3, 6.3, 3.3, and 2.3 μM, respectively.

Chemistry. 2015 Jul 27;21(31):11152-7.

Highly trans-selective arylation of Achmatowicz rearrangement products by reductive γ-deoxygenation and Heck-Matsuda reaction: asymmetric total synthesis of (-)-musellarins A-C and their analogues.[Pubmed: 26104266 ]

Fully functionalized pyranuloses derived from Achmatowicz rearrangement (AR) are versatile building blocks in organic synthesis. However, access to trans-2,6-dihydropyrans from pyranuloses remains underexplored.
METHODS AND RESULTS:
Herein, we report a new two-step trans arylation of AR products to access 2,6-trans-dihydropyranones. This new trans-arylation method built on numerous plausible, but unsuccessful, direct arylation reactions, including Ferrier-type and Tsuji-Trost-type reactions, was finally enabled by an unprecedented, highly regioselective γ-deoxygenation of AR products by using Zn/HOAc and a diastereoselective Heck-Matsuda coupling. The synthetic utility of the reaction was demonstrated in the first asymmetric total synthesis of (-)-musellarin A, (-)-musellarin B, (-)-Musellarin C and 12 analogues in 11-12 steps.
CONCLUSIONS:
The brevity and efficiency of our synthetic route permitted preparation of enantiomerically pure musellarins and analogues (>20 mg) for preliminary cytotoxicity evaluation, which led us to identify two analogues with three-to-six times greater potency than the musellarins as promising new leads.