Novel Brassinosteroid Analogues with 3,6 Dioxo Function, 24-Nor-22(S)-Hydroxy Side Chain and p-Substituted Benzoate Function at C-23-Synthesis and Evaluation of Plant Growth Effects.

Brassinosteroids (BRs) are an important group of polyhydroxylated naturally occurring steroidal phytohormones found in the plant kingdom in extremely low amounts. Due to the low concentrations in which these compounds are found, much effort has been dedicated to synthesizing these compounds or their structural analogs using natural and abundant sterols. In this work, we report the synthesis of new brassinosteroid analogs obtained from hyodeoxycholic acid, with a 3,6 dioxo function, 24-Nor-22(S)-hydroxy side chain and p-substituted benzoate function at C-23. The plant growth activities of these compounds were evaluated by two different bioassays: rice lamina inclination test (RLIT) and BSI. The results show that BRs' analog with p-Br (compound 41f) in the aromatic ring was the most active at 1 × 10-8 M in the RLIT and BSI assays. These results are discussed in terms of the chemical structure and nature of benzoate substituents at the para position. Electron-withdrawing and size effects seems to be the most important factor in determining activities in the RLIT assay. These results could be useful to propose a new structural requirement for bioactivity in brassinosteroid analogs.

Antimicrobial Activity of Drimanic Sesquiterpene Compounds from Drimys winteri against Multiresistant Microorganisms.

In this work, a group of ten sesquiterpene drimanes, including polygodial (1), isopolygodial (2), and drimenol (3) obtained from the bark of Drimys winteri F. and seven synthetic derivatives, were tested in vitro against a unique panel of bacteria, fungi, and oomycetes with standardized procedures against bacterial strains K. pneumoniae, S. tiphy, E. avium, and E. coli. The minimum inhibitory concentrations and bactericidal activities were evaluated using standardized protocols. Polygodial (1) was the most active compound, with MBC 8 µg/mL and MIC 16 µg/mL in E. avium; MBC 16 µg/mL and MIC 32 µg/mL in K. pneumoniae; MBC 64 µg/mL and MIC 64 µg/mL in S. typhi; and MBC 8 µg/mL and MIC 16 µg/mL and MBC 32 µg/mL and MIC 64 µg/mL in E. coli, respectively. The observed high potency could be attributed to the presence of an aldehyde group at the C8-C9 position. The antifungal activity of 1 from different microbial isolates has been evaluated. The results show that polygodial affects the growth of normal isolates and against filamentous fungi and oomycetes with MFC values ranging from 8 to 64 µg/mL. Sesquiterpene drimanes isolated from this plant have shown interesting antimicrobial properties.

Effect of Cannabis sativa L. extracts, phytocannabinoids and their acetylated derivates on the SHSY-5Y neuroblastoma cells' viability and caspases 3/7 activation.

BACKGROUND: There is a need for novel treatments for neuroblastoma, despite the emergence of new biological and immune treatments, since refractory pediatric neuroblastoma is still a medical challenge. Phyto cannabinoids and their hemisynthetic derivatives have shown evidence supporting their anticancer potential. The aim of this research was to examine Phytocannabinoids or hemisynthetic cannabinoids, which reduce the SHSY-5Y, neuroblastoma cell line's viability. METHODS: Hexane and acetyl acetate extracts were produced starting with Cannabis sativa L. as raw material, then, 9-tetrahidrocannabinol, its acid counterpart and CBN were isolated. In addition, acetylated derivatives of THC and CBN were synthesized. The identification and purity of the chemicals was determined by High Performance Liquid Chromatography and 1H y 13C Magnetic Nuclear Resonance. Then, the capacity to affect the viability of SHSY-5Y, a neuroblastoma cell line, was examined using the resazurin method. Finally, to gain insight into the mechanism of action of the extracts, phytocannabinoids and acetylated derivatives on the examined cells, a caspase 3/7 determination was performed on cells exposed to these compounds. RESULTS: The structure and purity of the isolated compounds was demonstrated. The extracts, the phytocannabinoids and their acetylated counterparts inhibited the viability of the SHSY 5Y cells, being CBN the most potent of all the tested molecules with an inhibitory concentration of 50 percent of 9.5 µM. CONCLUSION: Each of the evaluated molecules exhibited the capacity to activate caspases 3/7, indicating that at least in part, the cytotoxicity of the tested phytocannabinoids and their hemi-synthetic derivatives is mediated by apoptosis.

Cytotoxic Activity, Topoisomerase I Inhibition and In Silico Studies of New Sesquiterpene-aryl Ester Derivatives of (-) Drimenol.

In this study, we aimed to evaluate two sets of sesquiterpene-aryl derivatives linked by an ester bond, their cytotoxic activities, and their capacity to activate caspases 3/7 and inhibit human topoisomerase I (TOP1). A total of 13 compounds were synthesized from the natural sesquiterpene (-)-drimenol and their cytotoxic activity was evaluated in vitro against three cancer cell lines: PC-3 (prostate cancer), HT-29 (colon cancer), MCF-7 (breast cancer), and an immortalized non-tumoral cell line (MCF-10). From the results, it was observed that 6a was the most promising compound due to its cytotoxic effect on three cancer cell lines and its selectivity, 6a was 100-fold more selective than 5-FU in MCF-7 and 20-fold in PC-3. It was observed that 6a also induced apoptosis by caspases 3/7 activity using a Capsase-Glo-3/7 assay kit and inhibited TOP1. A possible binding mode of 6a in a complex with TOP1-DNA was proposed by docking and molecular dynamics studies. In addition, 6a was predicted to have a good pharmacokinetic profile for oral administration. Therefore, through this study, it was demonstrated that the drimane scaffold should be considered in the search of new antitumoral agents.

New Brassinosteroid Analogs with 23,24-Dinorcholan Side Chain, and Benzoate Function at C-22: Synthesis, Assessment of Bioactivity on Plant Growth, and Molecular Docking Study.

The synthesis and biological evaluation of brassinosteroids (BRs) analogs with chemical modification in the side alkyl chain is a matter of current interest. Recently, a series of BR analogs with phenyl or benzoate groups in the alkyl chain have been reported. The effect of substitution in the aromatic ring on the biological activities of these new analogs has been evaluated, and the results suggest that the bioactivity is enhanced by substitution with an F atom. In this context, we have synthesized, characterized, and evaluated a series of new analogs of 23,24-bisnorcholenic type in which the benzoate group at the C-22 position is substituted with an F atom at "ortho or para" positions. Plant growth-promoting activities were evaluated by using the rice lamina inclination test and bean second internode biotest. The results obtained with both bioassays indicate that the compound with an F atom in the para position on the aromatic ring is the most active BR analog and in some cases is even more active than brassinolide. The docking study confirmed that compounds with an F atom adopt an orientation similar to that predicted for brassinolide, and the F atom in the "para" position generates an extra hydrogen bond in the predicted binding position.

Cytotoxic Effects on Breast Cancer Cell Lines of Chalcones Derived from a Natural Precursor and Their Molecular Docking Analysis.

This study aimed to determine the in vitro cytotoxicity and understand possible cytotoxic mechanisms via an in silico study of eleven chalcones synthesized from two acetophenones. Five were synthesized from a prenylacetophenone isolated from a plant that grows in the Andean region of the Atacama Desert. The cytotoxic activity of all the synthesized chalcones was tested against breast cancer cell lines using an MTT cell proliferation assay. The results suggest that the prenyl group in the A-ring of the methoxy and hydroxyl substituents of the B-ring appear to be crucial for the cytotoxicity of these compounds. The chalcones 12 and 13 showed significant inhibitory effects against growth in MCF-7 cells (IC50 4.19 ± 1.04 µM and IC50 3.30 ± 0.92 µM), ZR-75-1 cells (IC50 9.40 ± 1.74 µM and IC50 8.75 ± 2.01µM), and MDA-MB-231 cells (IC50 6.12 ± 0.84 µM and IC50 18.10 ± 1.65 µM). Moreover, these chalcones showed differential activity between MCF-10F (IC50 95.76 ± 1.52 µM and IC50 95.11 ± 1.97 µM, respectively) and the tumor lines. The in vitro results agree with molecular coupling results, whose affinity energies and binding mode agree with the most active compounds. Thus, compounds 12 and 13 can be considered for further studies and are candidates for developing new antitumor agents. In conclusion, these observations give rise to a new hypothesis for designing chalcones with potential cytotoxicity with high potential for the pharmaceutical industry.

New Amino Naphthoquinone Derivatives as Anti-Trypanosoma cruzi Agents Targeting Trypanothione Reductase.

To develop novel chemotherapeutic alternatives for the treatment of Chagas disease, in this study, a set of new amino naphthoquinone derivatives were synthesised and evaluated in vitro on the epimastigote and trypomastigote forms of Trypanosoma cruzi strains (NINOA and INC-5) and on J774 murine macrophages. The design of the new naphthoquinone derivatives considered the incorporation of nitrogenous fragments with different substitution patterns present in compounds with activity on T. cruzi, and, thus, 19 compounds were synthesised in a simple manner. Compounds 2e and 7j showed the lowest IC50 values (0.43 µM against both strains for 2e and 0.19 µM and 0.92 µM for 7j). Likewise, 7j was more potent than the reference drug, benznidazole, and was more selective on epimastigotes. To postulate a possible mechanism of action, molecular docking studies were performed on T. cruzi trypanothione reductase (TcTR), specifically at a site in the dimer interface, which is a binding site for this type of naphthoquinone. Interestingly, 7j was one of the compounds that showed the best interaction profile on the enzyme; therefore, 7j was evaluated on TR, which behaved as a non-competitive inhibitor. Finally, 7j was predicted to have a good pharmacokinetic profile for oral administration. Thus, the naphthoquinone nucleus should be considered in the search for new trypanocidal agents based on our hit 7j.

QSAR-driven synthesis of antiproliferative chalcones against SH-SY5Y cancer cells: Design, biological evaluation, and redesign.

Neuroblastoma is one of the most frequent types of cancer found in infants, and traditional chemotherapy has limited efficacy against this pathology. Thus, the development of new compounds with higher activity and selectivity than traditional drugs is a current challenge in medicinal chemistry research. In this study, we report the synthesis of 21 chalcones with antiproliferative activity and selectivity against the neuroblastoma cell line SH-SY5Y. Then, we developed three-dimensional quantitative structure-activity relationship models (comparative molecular field analysis and comparative molecular similarity index analysis) with high-quality statistical values (q2 > 0.7; r2 > 0.8; r2 pred > 0.7), using IC50 and selectivity index (SI) data as dependent variables. With the information derived from these theoretical models, we designed and synthesized 16 new molecules to prove their consistency, finding good antiproliferative activity against SH-SY5Y cells on these derivatives, with three of them showing higher SI than the referential drugs 5-fluorouracil and cisplatin, displaying also a proapoptotic effect comparable to these drugs, as proven by measuring their effects on executor caspases 3/7 activity induction, Bcl-2/Bax messenger RNA levels alteration, and DNA fragmentation promotion.

Chemical Analysis and In Vitro Bioactivity of Essential Oil of Laurelia sempervirens and Safrole Derivatives against Oomycete Fish Pathogens.

In this study, the essential oil (EO) from Laurelia sempervirens was analyzed by GC/MS and safrole (1) was identified as the major metabolite 1, was subjected to direct reactions on the oxygenated groups in the aromatic ring and in the side chain, and eight compounds (4 to 12) were obtained by the process. EO and compounds 4-12 were subjected to biological assays on 24 strains of the genus Saprolegnia, specifically of the species 12 S. parasitica and 12 S. australis. EO showed a significant effect against Saprolegnia strains. Compound 6 presents the highest activity against two resistant strains, with minimum inhibitory concentration (MIC) and minimum oomyceticidal concentration (MOC) values of 25 to 100 and 75 to 125 µg/mL, respectively. The results show that compound 6 exhibited superior activities compared to the commercial controls bronopol and azoxystrobin used to combat these pathogens.

Synthesis of New Brassinosteroid 24-Norcholane Type Analogs Conjugated in C-3 with Benzoate Groups.

The metabolism of brassinosteroid leads to structural modifications in the ring skeleton or the side alkyl chain. The esterification and glycosylation at C-3 are the most common metabolic pathways, and it has been suggested that conjugate brassinosteroids are less active or inactive. In this way, plants regulate the content of active brassinosteroids. In this work, the synthesis of brassinosteroid 24-norcholane type analogs conjugated at C-3 with benzoate groups, carrying electron donor and electron attractant substituents on the aromatic ring, is described. Additionally, their growth-promoting activities were evaluated using the Rice Lamina Inclination Test (RLIT) and compared with that exhibited by brassinolide (used as positive control) and non-conjugated analogs. The results indicate that at the lowest tested concentrations (10-8-10-7 M), all analogs conjugated at C-3 exhibit similar or higher activities than brassinolide, and the diasteroisomers with S configuration at C-22 are the more active ones. Increasing concentration (10-6 M) reduces the biological activities of analogs as compared to brassinolide.

Combined 3D-QSAR and docking analysis for the design and synthesis of chalcones as potent and selective monoamine oxidase B inhibitors.

Monoamine oxidases (MAOs) are important targets in medicinal chemistry, as their inhibition may change the levels of different neurotransmitters in the brain, and also the production of oxidative stress species. New chemical entities able to interact selectively with one of the MAO isoforms are being extensively studied, and chalcones proved to be promising molecules. In the current work, we focused our attention on the understanding of theoretical models that may predict the MAO-B activity and selectivity of new chalcones. 3D-QSAR models, in particular CoMFA and CoMSIA, and docking simulations analysis have been carried out, and their successful implementation was corroborated by studying twenty-three synthetized chalcones (151-173) based on the generated information. All the synthetized molecules proved to inhibit MAO-B, being ten out of them MAO-B potent and selective inhibitors, with IC50 against this isoform in the nanomolar range, being (E)-3-(4-hydroxyphenyl)-1-(2,2-dimethylchroman-6-yl)prop-2-en-1-one (152) the best MAO-B inhibitor (IC50 of 170 nM). Docking simulations on both MAO-A and MAO-B binding pockets, using compound 152, were carried out. Calculated affinity energy for the MAO-A was +2.3 Kcal/mol, and for the MAO-B was -10.3 Kcal/mol, justifying the MAO-B high selectivity of these compounds. Both theoretical and experimental structure-activity relationship studies were performed, and substitution patterns were established to increase MAO-B selectivity and inhibitory efficacy. Therefore, we proved that both 3D-QSAR models and molecular docking approaches enhance the probability of finding new potent and selective MAO-B inhibitors, avoiding time-consuming and costly synthesis and biological evaluations.

Design, synthesis, antifungal activity, and structure-activity relationship studies of chalcones and hybrid dihydrochromane-chalcones.

A series of ten chalcones (7a-j) and five new dihydrochromane-chalcone hybrids (7k-o) were synthesized and identified using spectroscopic techniques (IR, NMR, and MS). All compounds were evaluated in vitro against the B. cinerea and M. fructicola phytopathogens that affect a wide range of crops of commercial interest. All compounds were tested against both phytopathogens using the mycelial growth inhibition test, and it was found that two and five compounds had similar activity to that of the positive control for B. cinerea (7a = 43.9, 7c = 45.5, and Captan®= 24.8 µg/mL) and M. fructicola (7a = 48.5, 7d = 78.2, 7e = 56.1, 7f = 51.8, 7n = 63.2, and Mystic®= 21.6 µg/mL), respectively. To understand the key chalcone structural features for the antifungal activity on B. cinerea and M. fructicola, we developed structure-activity models with good statistical values (r2 and q2 higher than 0.8). For B. cinerea, the hydrogen bonding donor and acceptor and the atomic charge on C5 modulate the mycelial growth inhibition activity. In contrast, dipole moment and atomic charge on C1' and the carbonyl carbon modify the inhibition activity for M. fructicola. These results allow the design of other compounds with activities superior to those of the compounds obtained in this study.

Antigrowth activity and induction of apoptosis in human melanoma cells by Drymis winteri forst extract and its active components.

Melanoma is a highly invasive cancer that resists most conventional treatments. Therefore, there is an urgent need to identify alternative anticancer agents able to affect new molecular targets. Drimys winteri (Winteraceae) is a medicinal plant, employed in Brazil and many countries, in folk medicine against a variety of ailments, especially for the treatment of fevers, ulcers, pains, affections of respiratory tract and cancers. Previous phytochemical studies have isolated and identified the presence of diverse classes of secondary metabolites in this plant such as sesquiterpenes. In an ongoing to identify new natural anticancer compounds for the treatment and/or prevention of melanoma, we study the effects of Drimys winteri bark ethyl acetate extract and its sesquiterpenes drimenol, nordrimenone, isonordrimenone and polygodial on human melanoma cells. The treatment of melanoma cells with extract, drimenol, isordrimenone and polygodial resulted in a significant reduction in cell viability. But, polygodial showed the highest inhibitory growth activity. In addition, we reported an apoptotic response after treatment with drimenol, isordrimenone and polygodial that probably involves the reduction of Hsp70 expression and reactive oxygen species production. Alternatively, the inhibition of caspase cascade at higher concentrations, correlated with additional reactive oxygen species increase, probably switches natural product-induced cell death from apoptosis to necrosis. Therefore, this evidence provides a scientific support for the anticancer employ of Drimys winteri in traditional medicinal and suggests that active molecules can be considered potential candidates to be tested also in in vivo models, alone or in combination with chemotherapy agents, for the management of melanoma.

Biopesticide Activity from Drimanic Compounds to Control Tomato Pathogens.

Tomato crops can be affected by several infectious diseases produced by bacteria, fungi, and oomycetes. Four phytopathogens are of special concern because of the major economic losses they generate worldwide in tomato production; Clavibacter michiganensis subsp. michiganensis and Pseudomonas syringae pv. tomato, causative agents behind two highly destructive diseases, bacterial canker and bacterial speck, respectively; fungus Fusarium oxysporum f. sp. lycopersici that causes Fusarium Wilt, which strongly affects tomato crops; and finally, Phytophthora spp., which affect both potato and tomato crops. Polygodial (1), drimenol (2), isonordrimenone (3), and nordrimenone (4) were studied against these four phytopathogenic microorganisms. Among them, compound 1, obtained from Drimys winteri Forst, and synthetic compound 4 are shown here to have potent activity. Most promisingly, the results showed that compounds 1 and 4 affect Clavibacter michiganensis growth at minimal inhibitory concentrations (MIC) values of 16 and 32 µg/mL, respectively, and high antimycotic activity against Fusarium oxysporum and Phytophthora spp. with MIC of 64 µg/mL. The results of the present study suggest novel treatment alternatives with drimane compounds against bacterial and fungal plant pathogens.

(-)-Shikimic Acid as a Chiral Building Block for the Synthesis of New Cytotoxic 6-Aza-Analogues of Angucyclinones.

We describe the syntheses of nine new angucyclinone 6-aza-analogues, achieved through a hetero Diels-Alder reaction between the shikimic acid derivative-azadiene 13, with different naphthoquinones. The cytotoxic activity of the new synthesized compounds and five angucyclinones, previously reported, was evaluated in vitro against three cancer cell lines: PC-3 (prostate cancer), HT-29 (colon cancer), MCF-7 (breast cancer), and one non-tumoral cell line, human colon epithelial cells (CCD841 CoN). Our results showed that most 6-azadiene derivatives exhibited significant cytotoxic activities, which was demonstrated by their IC50 values (less than 10 µM), especially for the most sensitive cells, PC-3 and HT-29. From a chemical point of view, depending on the protected group of ring A and the pattern of substitution on ring D, cytotoxicity elicited these compounds, in terms of their potency and selectivity. Therefore, according to these chemical features, the most promising agents for every cancer cell line were 7a, 17, and 19c for PC-3 cells; 7a, 17, and 20 for HT-29 cells, and 19a for MCF-7 cells.

Antifeedant effect of polygodial and drimenol derivatives against Spodoptera frugiperda and Epilachna paenulata and quantitative structure-activity analysis.

BACKGROUND: The antifeedant activity of 18 sesquiterpenoids of the drimane family (polygodial, drimenol and derivatives) was investigated. RESULTS: Polygodial, drimanic and nordrimanic derivatives were found to exert antifeedant effects against two insect species, Spodoptera frugiperda and Epilachna paenulata, which are pests of agronomic interest, indicating that they have potential as biopesticide agents. Among the 18 compounds tested, the epoxynordrimane compound (11) and isonordrimenone (4) showed the highest activity [50% effective concentration (EC50 ) = 23.28 and 25.63 nmol cm-2 , respectively, against S. frugiperda, and 50.50 and 59.00 nmol/cm2 , respectively, against E. paenulata]. CONCLUSION: The results suggest that drimanic compounds have potential as new agents against S. frugiperda and E. paenulata. A quantitative structure-activity relationship (QSAR) analysis of the whole series, supported by electronic studies, suggested that drimanic compounds have structural features necessary for increasing antifeedant activity, namely a C-9 carbonyl group and an epoxide at C-8 and C-9. © 2018 Society of Chemical Industry.

2D-QSAR and 3D-QSAR/CoMSIA Studies on a Series of (R)-2-((2-(1H-Indol-2-yl)ethyl)amino)-1-Phenylethan-1-ol with Human ß3-Adrenergic Activity.

The ß3 adrenergic receptor is raising as an important drug target for the treatment of pathologies such as diabetes, obesity, depression, and cardiac diseases among others. Several attempts to obtain selective and high affinity ligands have been made. Currently, Mirabegron is the only available drug on the market that targets this receptor approved for the treatment of overactive bladder. However, the FDA (Food and Drug Administration) in USA and the MHRA (Medicines and Healthcare products Regulatory Agency) in UK have made reports of potentially life-threatening side effects associated with the administration of Mirabegron, casting doubts on the continuity of this compound. Therefore, it is of utmost importance to gather information for the rational design and synthesis of new ß3 adrenergic ligands. Herein, we present the first combined 2D-QSAR (two-dimensional Quantitative Structure-Activity Relationship) and 3D-QSAR/CoMSIA (three-dimensional Quantitative Structure-Activity Relationship/Comparative Molecular Similarity Index Analysis) study on a series of potent ß3 adrenergic agonists of indole-alkylamine structure. We found a series of changes that can be made in the steric, hydrogen-bond donor and acceptor, lipophilicity and molar refractivity properties of the compounds to generate new promising molecules. Finally, based on our analysis, a summary and a regiospecific description of the requirements for improving ß3 adrenergic activity is given.

Synthesis and Evaluation of Novel Oxyalkylated Derivatives of 2',4'-Dihydroxychalcone as Anti-Oomycete Agents against Bronopol Resistant Strains of Saprolegnia sp.

A series of novel oxyalkylchalcones substituted with alkyl groups were designed and synthesized, and the antioomycete activity of the series was evaluated in vitro against Saprolegnia strains. All tested O-alkylchalcones were synthesized by means of nucleophilic substitution from the natural compound 2',4'-dihydroxychalcone (1) and the respective alkyl bromide. The natural chalcone (1) and 10 synthetic oxyalkylchalcones (2-11) were tested against Saprolegnia parasitica and Saprolegnia australis. Among synthetic analogs, 2-hydroxy,4-farnesyloxychalcone (11) showed the most potent activity against Saprolegnia sp., with MIC and MOC values of 125 µg/mL (similar to bronopol at 150 µg/mL) and 175 µg/mL, respectively; however, 2',4'-dihydroxychalcone (1) was the strongest and most active molecule, with MIC and MOC values of 6.25 µg/mL and 12.5 µg/mL.

Antiproliferative effect and apoptotic activity of linear geranylphenol derivatives from phloroglucinol and orcinol.

Sixteen synthetic linear derivatives geranylphenols, were obtained from phloroglucinol and orcinol, and cytotoxic activity was evaluated in vitro against cancer cell lines (HT-29, PC-3, MDA-MB231, DU-145) and one non-tumor cell line, human dermal fibroblast (HDF). IC50 values were determined at concentrations of 0-100 µM of each compound for 72 h. Compounds 12, 13, 17, 21, 22 and 25, showed cytotoxic activity. To elucidate whether these compounds reduce cell viability by inducing apoptosis, cell lines MCF-7, PC-3 and DHF were treated with each active compound 12, 13, 17, 21, 22 and 25 and were examined after Hoechst 33342 staining. The compounds 12, 13 and 17 induced apoptosis in various cancer cell lines, as shown by nuclear condensation and/or fragmentation. In addition, it was found that compounds 12 and 13, induced changes in mitochondrial membrane permeability in those cancer cell lines. Such induction was associated with the depletion of mitochondrial membrane potential. These activities led to the cleavage of caspases inducing the cell death process.

Chemical Characterization and Anti-Oomycete Activity of Laureliopsis philippianna Essential Oils against Saprolegnia parasitica and S. australis.

Laureliopsis philippiana (Looser) R. Schodde (Monimiaceae) is a native tree widespread in the forest areas in the south of Chile and Argentina, known for its medicinal properties and excellent wood. The aim of this study was to evaluate the chemical composition of L. philippiana leaf and bark essential oils (EOs) using gas chromatography-mass spectrometry (GC-MS), and to quantify its anti-oomycete activity, specifically against Saprolegnia parasitica and S. australis. Only six components were identified in leaf EO, 96.92% of which are phenylpropanoids and 3.08% are terpenes. As for bark EO, 29 components were identified, representing 67.61% for phenylpropanoids and 32.39% for terpenes. Leaf EO was characterized mainly by safrole (96.92%) and ß-phellandrene (1.80%). Bark EO was characterized mainly by isosafrole (30.07%), safrole (24.41%), eucalyptol (13.89%), methyleugenol (7.12%), and eugenol (6.01%). Bark EO has the most promising anti-Saprolegnia activity, with a minimum inhibition concentration (MIC) value of 30.0 µg/mL against mycelia growth and a minimum fungicidal concentration (MFC) value of 50.0 µg/mL against spores; for leaf EO, the MIC and MFC values are 100 and 125 µg/mL, respectively. These findings demonstrate that bark EO has potential to be developed as a remedy for the control of Saprolegnia spp. in aquaculture.