Harwoko Harwoko

Dr. Harwoko Harwoko

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 June 2019 in Natural Product Research
Verified
Journal Article
Closed access
HHHarwoko Harwoko
Harwoko Harwoko
Georgios DaletosGeorgios Daletos
Georgios Daletos
FSFabian Stuhldreier
Fabian Stuhldreier
JLJungho Lee
Jungho Lee
SWSebastian Wesselborg
Sebastian Wesselborg
Peter ProkschPeter Proksch
Peter Proksch
A new epidithiodiketopiperazine (ETP), pretrichodermamide G (1), along with three known (epi)dithiodiketopiparazines (2-4) were isolated from cultures of Trichoderma harzianum and Epicoccum nigrum, endophytic fungi associated with medicinal plants Zingiber officinale and Salix sp., respectively. The structure of the new compound (1) was established on the basis of spectroscopic data, including 1D/2D NMR and HRESIMS. The isolated compounds were investigated for their antifungal, antibacterial and cytotoxic potential against a panel of microorganisms and cell lines. Pretrichodermamide A (2) displayed antimicrobial activity towards the plant pathogenic fungus Ustilago maydis and the human pathogenic bacterium Mycobacterium tuberculosis with MIC values of 1 mg/mL (2 mM) and 25 µg/mL (50 µM), respectively. Meanwhile, epicorazine A (3) exhibited strong to moderate cytotoxicity against L5178Y, Ramos, and Jurkat J16 cell lines with IC50 values ranging from 1.3 to 28 µM. Further mechanistic studies indicated that 3 induces apoptotic cell death.

1 October 2020 in Fitoterapia
Verified
Journal Article
Closed access
HHHarwoko Harwoko
Harwoko Harwoko
JLJungho Lee
Jungho Lee
RHRudolf Hartmann
Rudolf Hartmann
AMAttila Mandi
Attila Mandi
TKTibor Kurtán
Tibor Kurtán
Peter ProkschPeter Proksch
Peter Proksch

1 September 2019 in Bioorganic & Medicinal Chemistry
Verified
Journal Article
Closed access
NANada M. Abdel-Wahab
Nada M. Abdel-Wahab
HHHarwoko Harwoko
Harwoko Harwoko
Werner E.G. MüllerWerner E.G. Müller
Werner E.G. Müller
AHAlexandra Hamacher
Alexandra Hamacher
MKMatthias U. Kassack
Matthias U. Kassack
PPPeter Proksch
Peter Proksch

2 December 2019 in ChemistrySelect
Verified
Journal Article
Open access
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HHHarwoko Harwoko
Harwoko Harwoko
RHRudolf Hartmann
Rudolf Hartmann
GDGeorgios Daletos
Georgios Daletos
EAElena Ancheeva
Elena Ancheeva
MFMarian Frank
Marian Frank
Peter ProkschPeter Proksch
Peter Proksch
Fermentation of the fungus Epicoccum nigrum isolated from leaves of Salix sp. on green lentil solid medium yielded the flavonol kaempferol ( 3 ) as well as two kaempferol O ‐diglycosides ( 1 and 2 ) including the new compound 1 . The fungal flavonoids bear strong structural similarities to kaempferol derivatives such as kaempferol O ‐glycoside ( 4 ) being present in green lentils. Furthermore, feeding experiments were conducted by adding flavonoids (kaempferol and rutin) as precursors to solid rice media followed by HPLC and LC‐MS analyses. Fermentation of the fungus on flavonoid free solid rice medium afforded flavonoid free extracts indicating that the fungal flavonoids originate through hydrolytic cleavage of kaempferol glycosides such as 4 followed by glycosylation and acetylation. This study suggests that E. nigrum is capable of biotransformation reactions of plant derived flavonoids whereas de novo biosynthesis of flavonoids is less likely.

27 July 2020 in Molekul
Verified
Journal Article
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WWWarsinah Warsinah
Warsinah Warsinah
HBHanif Nasiatul Baroroh
Hanif Nasiatul Baroroh
HHHarwoko Harwoko
Harwoko Harwoko
Free radical in the body could cause degenerative diseases such as diabetes mellitus and hyperlipidemia, which could be prevented by the supplementation of antioxidant whether it is synthetic or natural. Flavanoids is a phenolic compound, was extracted from natural sources is known for its antioxidative potential. This research aimed to investigate the active compounds in brotowali (Tinospora crispa) stem to find new antioxidative potential using its ability to bind 2, 2’-diphenyl-1-picrylhydrazyl (DPPH). Brotowali stem was extracted using ethanol and fractioned using n-hexane, ethyl acetate, and water. Water fraction was hydrolyzed by chloric acid. The antioxidant activity of ethanol extract, water fraction, and hydrolized water fraction (subfraction I and subfraction II) were determined using spectrophotometry (DPPH methods). The compound of flavonoid was identified using KLT with AlCl3 reagent spray. The results showed that ethanol extract and water fraction of brotowali stem contained flavonoid glycoside of flavonol group. Antioxidant activity, quantified using IC50, of ethanol extract, water fraction, subfraction I and subfractiont II were 49.92μg/mL, 38.25 μg/mL, 36.12 μg/mL, and 16.18 μg/mL, respectively. In addition, this research was found that hydrolysis of water fraction using chloric acid like in subfraction I and subfraction II was able to improve its antioxidant activity.

1 January 2020 in Journal of Reports in Pharmaceutical Sciences
Verified
Journal Article
Closed access
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HHHarwoko Harwoko
Harwoko Harwoko
WWWarsinah Warsinah
Warsinah Warsinah
Background: Tinospora crispa is used in folk medicines for the treatment of gout, rheumatoid arthritis, and internal inflammation. The presence of flavonoids, polyphenols, glycosides, and alkaloids in T. crispa stem is supposed to contribute to these therapeutic effects. This study aimed to analyze qualitative and quantitative phytochemical of purified extract of T. crispa stem (PETS) and to evaluate the in vivo antihyperuricemic effect. Materials and Methods: First, total flavonoid and total alkaloid contents of PETS were determined by colorimetric and gravimetric methods. After that, potassium oxonate-induced hyperuricemic mice were treated with three doses of PETS at 50, 100, and 200 mg/kg, and hydroalcoholic extract at 500 mg/kg. Moreover, allopurinol at 10 mg/kg and sodium carboxymethylcellulose 0.5% were orally administered as positive and negative controls, respectively. Serum uric acid levels were measured by ultraviolet–visible spectrophotometry. Results: The high flavonoids content (31.08% ± 1.77% rutin equivalent) in T. crispa stem possesses a potential as uricostatic in the treatment of gout. The purified extract of T. crispa stem at a dose of 100 mg/kg revealed a significant uric acid–lowering effect compared with negative control (P < 0.05). Conclusion: This study indicates the potential of T. crispa purified extracts in the treatment of hyperuricemia and gout.