<i>In vitro</i>synergistic antibacterial activities of helvolic acid on multi-drug resistant<i>Staphylococcus aureus</i>

Qin, Ling; Li, Bogang; Guan, Jipeng; Zhang, Guolin

doi:10.1080/14786410801972813

Cited by 15 publications

(9 citation statements)

References 26 publications

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“…This was the reason for the very few peaks identified by the MS/HRMS approach compared to the previous cases. Nonetheless, the known antibacterial nortriterpenoid, helvolic acid was identified by MS/HRMS (Figure 9) [68,69] consistent with the biological activity of the fraction. In full scan, ESI + identification was not based on the [M + H] + but rather the accuracy of the fragment at m / z 509.2902 [C 31 H 41 O 6 ] + which was the most abundant peak in the spectrum (Figure 9A).…”

Section: Resultsmentioning

confidence: 84%

Accurate Dereplication of Bioactive Secondary Metabolites from Marine-Derived Fungi by UHPLC-DAD-QTOFMS and a MS/HRMS Library

et al. 2014

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In drug discovery, reliable and fast dereplication of known compounds is essential for identification of novel bioactive compounds. Here, we show an integrated approach using ultra-high performance liquid chromatography-diode array detection-quadrupole time of flight mass spectrometry (UHPLC-DAD-QTOFMS) providing both accurate mass full-scan mass spectrometry (MS) and tandem high resolution MS (MS/HRMS) data. The methodology was demonstrated on compounds from bioactive marine-derived strains of Aspergillus, Penicillium, and Emericellopsis, including small polyketides, non-ribosomal peptides, terpenes, and meroterpenoids. The MS/HRMS data were then searched against an in-house MS/HRMS library of ~1300 compounds for unambiguous identification. The full scan MS data was used for dereplication of compounds not in the MS/HRMS library, combined with ultraviolet/visual (UV/Vis) and MS/HRMS data for faster exclusion of database search results. This led to the identification of four novel isomers of the known anticancer compound, asperphenamate. Except for very low intensity peaks, no false negatives were found using the MS/HRMS approach, which proved to be robust against poor data quality caused by system overload or loss of lock-mass. Only for small polyketides, like patulin, were both retention time and UV/Vis spectra necessary for unambiguous identification. For the ophiobolin family with many structurally similar analogues partly co-eluting, the peaks could be assigned correctly by combining MS/HRMS data and m/z of the [M + Na]+ ions.

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Section: Resultsmentioning

confidence: 84%

Accurate Dereplication of Bioactive Secondary Metabolites from Marine-Derived Fungi by UHPLC-DAD-QTOFMS and a MS/HRMS Library

et al. 2014

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“…Previous studies have reported that helvolic acid exhibits antibacterial activities mainly against Gram-positive bacteria (Chain et al 1943; Qin et al 2009). The MICs against the Gram-positive bacteria reported in these studies are in the range 4–16 mg L −1 and are higher than in the current study.…”

Section: Resultsmentioning

confidence: 98%

Helvolic acid, an antibacterial nortriterpenoid from a fungal endophyte,Xylariasp. of orchidAnoectochilus setaceusendemic to Sri Lanka

et al. 2014

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An endophytic fungus was isolated from surface sterilized leaf segments of Anoectochilus setaceus, an orchid endemic to Sri Lanka, and was identified as Xylaria sp. by morphological characters and DNA sequencing. Bioassay-guided chromatographic fractionation of the organic extract of a laboratory culture of this fungus led to the isolation of the known antibacterial helvolic acid. Helvolic acid was active against the Gram-positive bacteria, Bacillus subtilis [minimal inhibitory concentrations (MIC), 2 μg mL−1] and methicillin-resistant Staphylococcus aureus (MIC, 4 μg mL−1).

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“…Compound 61 also exhibited synergistic effects with erythromycin on all tested multi-drug resistant Staphylococcus aureus and with penicillin and tetracycline on some multi-drug resistant S. aureus strains. Enhanced effect was also found in time-kill studies on multi-drug resistant S. aureus strains [77]. …”

Section: Fusidane Triterpenesmentioning

confidence: 96%

Protostane and Fusidane Triterpenes: A Mini-Review

et al. 2013

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Protostane triterpenes belong to a group of tetracyclic triterpene that exhibit unique structural characteristics. Their natural distribution is primarily limited to the genus Alisma of the Alismataceae family, but they have also been occasionally found in other plant genera such as Lobelia, Garcinia, and Leucas. To date, there are 59 known structures of protostane. Many of them have been reported to possess biological properties such as improving lipotropism, hepato-protection, anti-viral activity against hepatitis B and HIV-I virus, anti-cancer activity, as well as reversal of multidrug resistance in cancer cells. On the other hand, fusidanes are fungal products characterized by the 29-nor protostane structures. They possess antibiotic properties against staphylococci, including the methicillin-resistant staphylococcus aureus (MRSA). Fusidic acid is a representative member which has found clinical applications. This review covers plant sources of the protostanes, their structure elucidation, characteristic structural and spectral properties, as well as biological activities. The fungal sources, structural features, structure-activity relationship and biological activities of fusidanes are also covered in this review. Additionally, the biogenesis of these two types of triterpene is discussed and a refined pathway is proposed.

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In vitrosynergistic antibacterial activities of helvolic acid on multi-drug resistantStaphylococcus aureus

Cited by 15 publications

References 26 publications

Accurate Dereplication of Bioactive Secondary Metabolites from Marine-Derived Fungi by UHPLC-DAD-QTOFMS and a MS/HRMS Library

Accurate Dereplication of Bioactive Secondary Metabolites from Marine-Derived Fungi by UHPLC-DAD-QTOFMS and a MS/HRMS Library

Helvolic acid, an antibacterial nortriterpenoid from a fungal endophyte,Xylariasp. of orchidAnoectochilus setaceusendemic to Sri Lanka

Protostane and Fusidane Triterpenes: A Mini-Review

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