scholarly journals Inhibitory effect of aflastatin A on melanin biosynthesis by Colletotrichum lagenarium

Microbiology ◽  
2001 ◽  
Vol 147 (9) ◽  
pp. 2623-2628 ◽  
Author(s):  
Susumu Okamoto ◽  
Masaru Sakurada ◽  
Yasuyuki Kubo ◽  
Gento Tsuji ◽  
Isao Fujii ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Colletotrichum Lagenarium ◽  
Melanin Biosynthesis

Relation between pigment intensity and penetrating ability in appressoria of Colletotrichum lagenarium

1987 ◽  
Vol 33 (10) ◽  
pp. 870-873 ◽  
Author(s):  
Yasuyuki Kubo ◽  
Iwao Furusawa ◽  
Jiko Shishiyama
Keyword(s):  
Parent Strain ◽  
Colletotrichum Lagenarium ◽  
Melanin Biosynthesis ◽  
Glass Slides ◽  
Albino Mutant

Mutant 8004 of Colletotrichum lagenarium formed slightly pigmented appressoria. The appressoria germinated laterally on glass slides, but could penetrate nitrocellulose membranes. The slightly pigmented appressoria of the albino mutant 79215 were observed to behave in a similar manner when treated with 100 μM scytalone. The appressorial pigmentation of mutant 8004 was increased by the application of scytalone, and mature appressorial pigmentation, indistinguishable from that of the parent strain 104-T, was observed when appressoria were treated with 100 μM scytalone, a lower concentration than that needed for mature pigmentation of the albino mutant. The sensitivity to tricyclazole of appressorial pigmentation of mutant 8004 was higher than that of the parent strain 104-T. These results suggest that, although melanin biosynthesis is essential for appressorial penetration, slight pigmentation is sufficient.

scholarly journals Inhibitory Effect of Gnetin C, a Resveratrol Dimer from Melinjo (Gnetum gnemon), on Tyrosinase Activity and Melanin Biosynthesis

2012 ◽  
Vol 35 (6) ◽  
pp. 993-996 ◽  
Author(s):  
Miyako Yanagihara ◽  
Maiko Yoshimatsu ◽  
Akinori Inoue ◽  
Tomoko Kanno ◽  
Tomoki Tatefuji ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Tyrosinase Activity ◽  
Melanin Biosynthesis ◽  
Gnetum Gnemon

Molecular characterization of prophenoloxidase-1 (PPO1) and the inhibitory effect of kojic acid on phenoloxidase (PO) activity and on the development ofZeugodacus tau(Walker) (Diptera: Tephritidae)

2018 ◽  
Vol 109 (2) ◽  
pp. 236-247 ◽  
Author(s):  
H.-H. Zhang ◽  
M.-J. Luo ◽  
Q.-W. Zhang ◽  
P.-M. Cai ◽  
A. Idrees ◽  
...  
Keyword(s):  
Kojic Acid ◽  
Normal Growth ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Pupal Weight ◽  
Mrna Levels ◽  
Melanin Biosynthesis ◽  
Horticultural Pest ◽  
Inhibition Experiment

AbstractPhenoloxidase (PO) plays a key role in melanin biosynthesis during insect development. Here, we isolated the 2310-bp full-length cDNA of PPO1 fromZeugodacus tau, a destructive horticultural pest. qRT-polymerase chain reaction showed that theZtPPO1transcripts were highly expressed during larval–prepupal transition and in the haemolymph. When the larvae were fed a 1.66% kojic acid (KA)-containing diet, the levels of theZtPPO1transcripts significantly increased by 2.79- and 3.39-fold in the whole larvae and cuticles, respectively, while the corresponding PO activity was significantly reduced; in addition, the larval and pupal durations were significantly prolonged; pupal weights were lowered; and abnormal phenotypes were observed. Anin vitroinhibition experiment indicated that KA was an effective competitive inhibitor of PO inZ. tau. Additionally, the functional analysis showed that 20E could significantly up-regulate the expression ofZtPPO1, induce lower pupal weight, and advance pupation. Knockdown of theZtPPO1gene by RNAi significantly decreased mRNA levels after 24 h and led to low pupation rates and incomplete pupae with abnormal phenotypes during the larval-pupal interim period. These results proved that PO is important for the normal growth ofZ. tauand that KA can disrupt the development of this pest insect.

Inhibition of Tyrosinase by Protocatechuic Aldehyde

2004 ◽  
Vol 32 (01) ◽  
pp. 97-103 ◽  
Author(s):  
Jae Kyung No ◽  
Min Sun Kim ◽  
You Jung Kim ◽  
Song Ja Bae ◽  
Jae Sue Choi ◽  
...  
Keyword(s):  
Competitive Inhibition ◽  
Salvia Miltiorrhiza ◽  
Inhibitory Effect ◽  
Tyrosinase Activity ◽  
Medical Problems ◽  
Melanin Biosynthesis ◽  
Rate Limiting Step ◽  
Protocatechuic Aldehyde ◽  
Dependent Inhibition ◽  
Potent Inhibitory Effect

The purpose of this study was to determine the inhibitory action of protocatechuic aldehyde (PCA) on tyrosinase activity. PCA is one of the compounds found in the root of Salvia miltiorrhiza. Our study documented that PCA has a potent inhibitory effect on tyrosinase, which catalyzes the rate-limiting step of melanin biosynthesis. Although melanin biosynthesis has an essential function normally in human skin for defense against ultraviolet light of the sun, its abnormal activity as seen in pigmentation disorder could lead to serious medical problems. Our data showed that PCA, with concentrations ranging from 1×10-5 M to 8×10-5 M , exhibited dose-dependent inhibition of the enzyme activity with 50% of inhibition at 19.92×10-6 M . A further kinetic analysis on PCA inactivation of tyrosinase activity revealed a competitive inhibition of the enzyme at the L-tyrosine binding site. The findings of our present study merit further research on the applicability of PCA as a potential agent for treatment of pigmentation disorder.

scholarly journals Multiple Contributions of Peroxisomal Metabolic Function to Fungal Pathogenicity in Colletotrichum lagenarium

2006 ◽  
Vol 72 (9) ◽  
pp. 6345-6354 ◽  
Author(s):  
Makoto Asakura ◽  
Tetsuro Okuno ◽  
Yoshitaka Takano
Keyword(s):  
Host Plant ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Acetate Metabolism ◽  
Colletotrichum Lagenarium ◽  
Melanin Biosynthesis ◽  
Fungal Pathogenicity ◽  
Peroxisomal Targeting ◽  
The Glyoxylate Cycle ◽  
Host Invasion

ABSTRACT In Colletotrichum lagenarium, which is the causal agent of cucumber anthracnose, PEX6 is required for peroxisome biogenesis and appressorium-mediated infection. To verify the roles of peroxisome-associated metabolism in fungal pathogenicity, we isolated and functionally characterized ICL1 of C. lagenarium, which encodes isocitrate lyase involved in the glyoxylate cycle in peroxisomes. The icl1 mutants failed to utilize fatty acids and acetate for growth. Although Icl1 has no typical peroxisomal targeting signals, expression analysis of the GFP-Icl1 fusion protein indicated that Icl1 localizes in peroxisomes. These results indicate that the glyoxylate cycle that occurs inside the peroxisome is required for fatty acid and acetate metabolism for growth. Importantly, in contrast with the pex6 mutants that form nonmelanized appressoria, the icl1 mutants formed appressoria that were highly pigmented with melanin, suggesting that the glyoxylate cycle is not essential for melanin biosynthesis in appressoria. However, the icl1 mutants exhibited a severe reduction in virulence. Appressoria of the icl1 mutants failed to develop penetration hyphae in the host plant, suggesting that ICL1 is involved in host invasion. The addition of glucose partially restored virulence of the icl1 mutant. Heat shock treatment of the host plant also enabled the icl1 mutants to develop lesions, implying that the infection defect of the icl1 mutant is associated with plant defense. Together with the requirement of PEX6 for appressorial melanization, our findings suggest that peroxisomal metabolic pathways play functional roles in appressorial melanization and subsequent host invasion steps, and the latter step requires the glyoxylate cycle.

Anti-Melanogenic Activity of p-Chlorophenyl Benzyl Ether in α-MSH-Induced Mouse Melanoma B16F10 Cells

2019 ◽  
Vol 819 ◽  
pp. 118-123
Author(s):  
Wassana Riam-Amatakun ◽  
Panupan Limpachayaporn ◽  
Jhoan Rhea L. Pizon ◽  
Praneet Opanasopit ◽  
Nopparat Nuntharatanapon
Keyword(s):  
Kojic Acid ◽  
Positive Association ◽  
Inhibitory Effect ◽  
Tyrosinase Activity ◽  
Dependent Manner ◽  
Benzyl Ether ◽  
Melanin Content ◽  
Synthetic Compound ◽  
Melanin Biosynthesis ◽  
B16f10 Cells

Melanin is cutaneous pigment which level of its production determines skin complexion. Overproduction of melanin, frequently promoted by UV rays, results in darkening of the skin. Inhibition of tyrosinase activity, a core component in melanin biosynthesis, is one of the mechanisms of depigmenting agents. Hydroquinone and kojic acid are the examples of well-known whitening agents widely used in both pharmaceutical and cosmetic products. However, their adverse effect issues still needed to be overcome. A recent study showed that p-chlorophenyl benzyl ether (Cl-benz), a new synthetic compound, more strongly inhibited mushroom tyrosinase than kojic acid. In the current study, cytotoxicity, anti-melanogenic activity and anti-tyrosinase activity of Cl-benz were performed in mouse B16F10 melanoma cells compared to kojic acid. After 24 h of treatment on B16F10 cells, the cytotoxicity was not observed with Cl-benz and kojic acid. However, after incubation for 48 h, kojic acid at a concentration of 500 μM reduced cell viability less than 50%, whereas Cl-benz-treated cells showed negligible cytotoxicity. For cell-based assay, Cl-benz exhibited inhibitory effect similar to kojic acid. Melanin production in B16F10 cells was suppressed by Cl-benz in a dose dependent manner. One hundred micrograms of Cl-benz decreased melanin content in α-MSH by 66%. Moreover, the percentage of cellular tyrosinase activity of Cl-benz showed positive association with its corresponding melanin content. These results revealed that Cl-benz could inhibit melanogenesis via the mechanism of cellular tyrosinase inhibition. Accordingly, Cl-benz has potential to become a novel skin whitening agent in terms of efficacy and safety.

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