Gram-scale approach for ß-costic acid via allylic oxidation of ß-selinene.

ß-Costic acid is a sesquiterpene phytoalexin with acaricidal activity against Varroa destructor and antitrypanosomal activity. A concise and efficient method was developed for the synthesis of ß-costic acid via the allylic oxidation of ß-selinene, a component of celery seed oil.

The contact toxicity and toxic mechanism of essential oils from Pimenta racemosa and Eugenia caryophyllata against Haemaphysalis longicornis (Acari: Ixodidae).

Haemaphysalis longicornis, which is widely distributed in China, can transmit various tick-borne diseases such as severe fever with thrombocytopenia syndrome, babesiosis, rickettsia disease and so on, and do great harm to human health and the development of animal husbandry. Chemical acaricides are the most traditional tick control method, but because of its many shortcomings, there is an urgent need to find a substitute with high efficiency, environmental protection and low toxicity. It has been found that some plant essential oils (EOs) have good insecticidal activity and environmental safety. In this study, the components of EOs from Pimenta racemosa and Eugenia caryophyllata were analyzed by gas chromatography-mass spectrometry (GC-MS), and their potential for application in the control of Haemaphysalis longicornis were studied. Gas chromatography-mass spectrometry analysis showed that the main components of P. racemosa EO were eugenol (64.07%), those of E. caryophyllata EO were Hexadecanoic acid, 2-methylpropyl ester (51.84%) and eugenol (39.76%). Larval packet test showed that the EOs of P. racemosa and E. caryophyllata had significant acaricidal activity against unfed larvae of H. longicornis, with LC50 values of 1.20 mg/mL and 0.47 mg/mL and LC90 values of 8.76 mg/mL and 2.91 mg/mL, respectively. The P. racemosa EO, E. caryophyllata EO and eugenol showed significant acaricidal activity against unfed nymph H. longicornis, with LC50 values of 1.65 mg/mL, 2.29 mg/mL and 0.93 mg/mL and LC90 values of 5.03 mg/mL, 11.01 mg/mL and 4.77 mg/mL, respectively. The P. racemosa EO, E. caryophyllata EO and eugenol showed significant acaricidal activity against unfed adults H. longicornis, with LC50 values of 0.51 mg/mL, 2.57 mg/mL and 1.83 mg/mL and LC90 values of 2.44 mg/mL, 11.44 mg/mL and 2.54 mg/mL, respectively. Enzyme assays revealed that the E. caryophyllata EO and eugenol significantly inhibited the activity of carboxylesterase (CarE), eugenol significantly inhibited the activity of catalase (CAT), and two EOs and eugenol had no significant effect on acetylcholinesterase (AchE) (p < 0.05). The above results suggest that the essential oils from P. racemosa and E. caryophyllata have great potential for use as alternatives to synthetic acaricides for tick control.

Promising Algerian essential oils as natural acaricides against the honey bee mite Varroa destructor (Acari: Varroidae).

Varroosis induced by Varroa destructor Anderson and Trueman represents the most pathogenic and destructive disease affecting the western honey bee, Apis mellifera. In this study, we investigated the acaricidal activity against the Varroa mite using essential oils (EOs) from the aerial parts of four autochthonous Algerian herbal species, namely Artemisia herba alba, Artemisia campestris, Artemisia judaica and Ruta montana. EOs were obtained by means of hydrodistillation and their composition was characterized by gas chromatography-mass spectrometry. The toxicity of the selected EOs toward V. destructor and A. mellifera adult honey bees was evaluated using the complete exposure method. The results indicate the predominance of davanone (66.9%) in A. herba alba, ß-pinene (19.5%) in A. campestris, piperitone (68.7%) in A. judaica and 2-undecanone (70.1%) in R. montana EOs. Interestingly, the LC50 values coupled to bee mortality rates revealed that all tested oils exhibited significant acaricidal efficiency with selectivity ratio (SR) values of 10.77, 8.78, 5.62 and 3.73 for A. campestris, A. judaica, A. herba alba, and R. montana, respectively. These values were better than that of thymol (SR = 3.65), the positive control. These findings suggest that these EOs could be used as plant-derived veterinary acaricides to control varroosis in field conditions.

Design, Synthesis, and Acaricidal Activity of 2,5-Diphenyl-1,3-oxazoline Compounds.

By using a scaffold hopping/ring equivalent and intermediate derivatization strategies, a series of compounds of 2,5-diphenyl-1,3-oxazoline with substituent changes at the 5-phenyl position were prepared, and their acaricidal activity was studied. However, the synthesized 2,5-diphenyl-1,3-oxazolines showed lower activity against mite eggs and larvae compared to the 2,4-diphenyl-1,3-oxazolines with the same substituents. We speculate that there is a significant difference in the spatial extension direction of the substituents between the two skeletons of compounds, resulting in differences in their ability to bind to the potential target chitin synthase 1. This work is helpful in inferring the internal structure of chitin synthase binding pockets.

Evaluation of synergism in essential oils against the cattle tick Rhipicephalus microplus in Burkina Faso.

The cattle tick Rhipicephalus microplus affects animal production economically by reducing weight gain and milk production and causing diseases, such as babesiosis and anaplasmosis. Using synthetic acaricides to reduce their incidence has caused the emergence of resistant tick populations. The present study aimed to assess the in vitro acaricidal activity of combinations of essential oils (EOs) from Ocimum americanum, Ocimum gratissimum, and Lippia multiflora against R. microplus larvae. In fact, numerous biological properties have been reported on EOs from these three plants, including acaricidal properties. Hence, a larval immersion test was performed using a population of R. microplus resistant to synthetic acaricides used in Burkina Faso. Results revealed that EO from O. gratissimum was the most effective on R. microplus larvae with LC50 and LC90 values at 10.36 and 15.51 mg/mL, respectively. For EO combinations, the most significant synergistic effect was obtained by combination 6 (1/3 O. americanum + 2/3 O. gratissimum +1/6 L. multiflora), with a combination index value of 0.44. All combinations presented dose reduction index >1, indicating a favorable dose reduction. According to the literature, this is the first study to determine the combination effect of EOs from the abovementioned plants in controlling R. microplus activity in vitro. Thus, the combination of these EOs is an alternative to control the resistant populations of invasive cattle ticks.

Natural Products as Mite Control Agents in Animals: A Review.

Mites have been a persistent infectious disease affecting both humans and animals since ancient times. In veterinary clinics, the primary approach for treating and managing mite infestations has long been the use of chemical acaricides. However, the widespread use of these chemicals has resulted in significant problems, including drug resistance, drug residues, and environmental pollution, limiting their effectiveness. To address these challenges, researchers have shifted their focus towards natural products that have shown promise both in the laboratory and real-world settings against mite infestations. Natural products have a wide variety of chemical structures and biological activities, including acaricidal properties. This article offers a comprehensive review of the acaricidal capabilities and mechanisms of action of natural products like plant extracts, natural compounds, algae, and microbial metabolites against common animal mites.

In vitro acaricidal activity of Piper longum L. against amitraz resistant Rhipicephalus microplus (Acari: Ixodidae).

The cattle tick, Rhipicephalus microplus Canestrini (Acari: Ixodidae) is one of the most important tick species severely affecting health and causes huge losses to dairy industry. Chemical acaricides are mainly applied for tick control but development of resistance, environmental pollution and contamination of milk and meat products with residues has led to exploration alternative eco-friendly tick control strategies. The dried fruits of Piper longum L. (Indian long pepper, Thippali or Pippali) generally used as flavoring agent have also been shown to have insecticidal property. Different concentrations (0.625%-10%) of alcoholic and aqueous extracts of Piper longum L. were prepared and evaluated for acaricidal activity against amitraz resistant R. microplus adult and larval stages. Against larval stages a dose-dependent mortality response was recorded for both extracts and higher acaricidal property was exhibited by the alcoholic extract with LC50 and LC95 (95% CL) values of 0.488% (0.48-0.49) and 1.39% (1.35-1.44), respectively. Similarly, against adult engorged females, ethanolic extract showed higher acaricidal property with LC50 and LC95 (95% CL) values of 4.67% (4.61-4.74) and 12.38% (12.05-12.73), respectively. Significant (p < 0.05) reduction was recorded in reproductive index of ticks treated and but no effect on hatchability of eggs was recorded in treated groups. The present study establishes acaricidal activity of P. longum fruit extracts against both larval and adult stages of amitraz resistant population of cattle tick.

Lethal concentrations of Cymbopogon nardus essential oils and their main component citronellal on Varroa destructor and Apis mellifera.

Varroosis is a disease caused by the mite Varroa destructor, and it is considered one of the biggest threats to honey bee populations globally. Mite control is centered on the use of synthetic acaricides, such as amitraz and flumethrine. However, high usage of these chemicals is associated with a wide variety of undesirable effects on bee colonies, including the development of resistance and persistence of harmful residues of acaricides in hive products used by humans. Botanical extracts have been identified as a potentially suitable organic alternative to synthetic acaricides. Essential oils, such as clove, eucalyptus, lemongrass, and oregano, have been found to exhibit acaricidal activity against V. destructor. The main goal of this work was to assess the bioactivity of the Cymbopogon nardus essential oil from two different locations (Argentina and India), and the activity of its major component the monoterpene citronellal. According to our results, complete essential oil from India is more effective in controlling parasitosis than the isolated citronellal component. The essential oil of C. nardus from Argentina demonstrated promise for the control of varroosis, as well as exhibiting low toxicity against bees (LC50 = 11.84 µL/mL). In addition, this essential oil may avoid the problems caused by synthetic acaricides, such as the emergence of resistance foci in Varroa and residues in hive products. Future research needs to investigate the delivery of volatile essentials oils to target mite populations.

Evaluation of the in vitro acaricidal activity of ethanol extracts of seven Chinese medicinal herbs on Ornithonyssus sylviarum (Acari: Macronyssidae).

Ornithonyssus sylviarum (Acari: Macronyssidae) is a common ectoparasite that feeds on the blood of poultry. Following infestation, this mite will cause symptoms such as weight loss, anemia, and decreased egg production. To explore green and safe drugs for the prevention and treatment of O. sylviarum, this study evaluated the effects of ethanol extracts of seven Chinese medicinal herbs-Leonurus artemisia (motherwort), Illicium verum (star anise), Cinnamomum cassia (cinnamon), Hibiscus syriacus, Artemisia argyi (Chinese mugwort), Taraxacum sp. (dandelion), and Syzygium aromaticum (clove)-on O. sylviarum at different life stages. The results showed that different methods of administration affected the acaricidal efficacy of these plant extracts on O. sylviarum. After 6 h of administration with the fumigation method, the acaricidal efficacy of S. aromaticum on adults, nymphs and larvae of O. sylviarum reached 100%. 30 min after administration with the infiltration method, S. aromaticum, H. syriacus and L. artemisia showed acaricidal effects on adults and nymphs of O. sylviarum reaching 100%. In another experiment evaluating the inhibition of egg hatching of O. sylviarum with alcohol extracts of these seven herbs, at 48 h after treatment, A. argyi and C. cassia showed inhibition rates of 19.4%. The results of this study indicate that S. aromaticum induced mortality at all stages of O. sylviarum, whereas A. argyi was found to be the most effective at inhibiting the mite's egg hatching among the seven herbs. These herbs can therefore be used as potential substitutes for chemical pesticides to prevent and control O. sylviarum. These results provide practical knowledge for the control of O. sylviarum.

Acaricidal potential of active components derived from Alpinia galanga rhizome oils and their derivatives against Haemaphysalis longicornis (Acari: Ixodidae).

Acaricidal activities and acetylcholinesterase (AChE) inhibitory activities were evaluated of active constituents of the essential oil extracted from Alpinia galanga rhizomes cultivated from India and their derivatives against Haemaphysalis longicornis nymphs. In addition, the effect was investigated of active components of A. galanga oil on egg laying of adult females of H. longicornis and egg hatchability. Of the volatile components identified in A. galanga oil, ethyl cinnamate, ethyl methoxycinnamate, and methyl cinnamate at 0.32 mg/cm2 resulted in 100% mortality, respectively, indicating that the acaricidal activity of the A. galanga oil against H. longicornis nymphs could be attributed to these compounds. To evaluate the structure-activity relationship between cinnamate derivatives and their acaricidal activities, allyl cinnamate, benzyl cinnamate, isopropyl cinnamate, isobutyl cinnamate, and isoamyl cinnamate were selected. Among cinnamate derivatives tested, allyl cinnamate exhibited the most potent toxicity (LC50 = 0.055 mg/cm2) against H. longicornis nymphs. The allyl cinnamate was also tested for AChE activity in vivo in H. longicornis nymphs and was found to affect the AChE activity. Allyl cinnamate at 10-50 mg/mL inhibited egg laying of adult females of H. longicornis by 10-43%. Egg hatching was suppressed completely by treatment with allyl cinnamate at 50 mg/mL, whereas allyl cinnamate was minimally toxic against non-target earthworms, Eisenia fetida. These results suggest that allyl cinnamate can be used as an active ingredient for the development of eco-friendly tick acaricides against H. longicornis, a vector for Sever fever with thrombocytopenia syndrome (SFTS) virus.

Chemical composition of essential oils from Thymus mongolicus, Cinnamomum verum, and Origanum vulgare and their acaricidal effects on Haemaphysalis longicornis (Acari: Ixodidae).

Chemical acaricides are mainly used in traditional tick control, which leads to the emergence of tick resistance and concurrently results in environmental pollution. In the present study, the chemical constituents of essential oils (EOs) from Thymus mongolicus, Cinnamomum verum, and Origanum vulgare was analyzed, and their potential application was evaluated to control the vector tick Haemaphysalis longicornis, which is widely distributed over vast areas of Eurasia, Australia, and New Zealand. Gas chromatography-mass spectrometry analysis revealed that the phenols thymol and carvacrol accounted for 34.66% and 75.72% of the EOs of T. mongolicus and O. vulgare, respectively, whereas trans-cinnamaldehyde (49.42%) was the main constituent of C. verum EO. Immersion tests showed that the EOs of C. verum and O. vulgare had significant acaricidal activity against larval H. longicornis, with the 50% lethal concentration (LC50) being 16.07 and 18.02 mg/mL, respectively, and the 95% lethal concentration (LC95) being 120.37 and 130.09 mg/mL, respectively. The EOs of O. vulgare and T. mongolicus showed significant acaricidal activity against unfed adult H. longicornis, with LC50 being 43.50 and 44.21 mg/mL, respectively, and LC95 being 113.66 and 137.99 mg/mL, respectively. The fumigant toxicity test showed significant acaricidal activity of the three EOs against both unfed and engorged nymphal and adult H. longicornis. Enzyme assays revealed that the EOs of both C. verum and O. vulgare significantly inhibited glutathione S-transferase activity (P < 0.05). In contrast, the activities of carboxylesterase and multifunction oxidases were significantly inhibited by EOs extracted from all three plants (P < 0.05). Taken together, these findings suggest that plant EOs may serve as an environment-friendly alternative for synthetic acaricides in future tick control.

Two new 13-hydroxylated milbemycin metabolites from the genetically engineered strain Streptomyces avermitilis AVE-H39.

Two new milbemycin metabolites, 13α-hydroxymilbemycin ß13 (1) and 26-methyl-13α-hydroxymilbemycin ß13 (2), were isolated from the fermentation broth of a genetically engineered strain Streptomyces avermitilis AVE-H39. Their structures were determined by the comprehensive spectroscopic data, including 1 D, 2 D NMR, MS spectral analysis and the comparison with data from the literature. Compounds 1 and 2 not only exhibited potent acaricidal activities against Tetranychus cinnabarinus, but also had nematocidal activity against Bursaphelenchus xylophilus.

Comparing acaricidal and ovicidal activity of five terpenes from essential oils against Psoroptes cuniculi.

Essential oils and their components represent an appealing alternative strategy against parasitic mites. The chemical complexity and variability of essential oils limit their use and additional work is required to analyze the efficacy and application rate of essential oils' individual components. In the present study, the activity of five terpenes (terpinen-4-ol, citral, linalool, eugenol, and geraniol) was evaluated against Psoroptes cuniculi motile stages and eggs collected from naturally infected rabbits. Eugenol presented the best acaricidal efficacy with a median lethal concentration (LC50) value of less than 0.1% at 24 h, followed by geraniol (0.33%), linalool (0.38%), citral (0.46%), and terpinen-4-ol (0.66%). Geraniol and eugenol were able to kill all mites within 5 min at 1% concentration. The effective concentration to inhibit 50% (EC50) of egg hatching was 0.65%, 0.66%, 0.85%, 1.47%, and 2.87% for eugenol, geraniol, citral, terpinen-4-ol, and linalool, respectively. In conclusion, eugenol, geraniol, citral, terpinen-4-ol, and linalool should be considered as promising agents for the development of botanical acaricides against Psoroptes cuniculi.

Design, Synthesis, and Acaricidal Activity of Phenyl Methoxyacrylates Containing 2-Alkenylthiopyrimidine.

A series of novel phenyl methoxyacrylate derivatives containing a 2-alkenylthiopyrimidine substructure were designed, synthesized, and evaluated in terms of acaricidal activity. The structures of the title compounds were identified by 1H NMR, 13C NMR and high-resolution mass spectra (HRMS). Compound (E)-methyl 2-(2-((2-(3,3-dichloroallylthio)-6-(trifluoromethyl)pyrimidin-4-yloxy)methyl)phenyl)-3-methoxyacr-ylate (4j) exhibited significant acaricidal activity against Tetranychus cinnabarinus (T. cinnabarinus) in greenhouse tests possessing nearly twice the larvicidal and ovicidal activity compared to fluacrypyrim. Furthermore, the results of the field trials demonstrated that compound 4j could effectively control Panonychuscitri with long-lasting persistence and rapid action. The toxicology data in terms of LD50 value confirmed that compound 4j has a relatively low acute toxicity to mammals, birds, and honeybees.

In vitro assessment of synergistic combinations of essential oils against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

Rhipicephalus (Boophilus) microplus (Acari: Ixodidae), is one of the most important ectoparasite of cattle, responsible for causing severe economic losses in the tropical and subtropical regions of the world. The development of resistance to most of the commonly used chemical acaricides has stimulated the search for new herbal products as an eco-friendly tick control alternative. The aim of the present study was to evaluate the in vitro acaricidal activity of essential oils (EOs) of cloves (Syzygium aromaticum), bark of cinnamon (Cinnamomum zeylanicum) and leaves of lemon grass (Cymbopogon citratus) against unfed larvae of R. (B.)microplus by larval packet test. Also, various combinations were prepared by mixing of equal concentrations of any two and all three EOs and used to study the effects of interactions of mixtures against larvae of R. (B.) microplus. The lethal concentrations at 50% (LC50), 90% (LC90) and 99% (LC99) with 95% confidence limits (CL) were estimated by Probit analysis using PoloPlus. The computer software, CompuSyn, was used for determining the effects of interactions (synergistic, additive or antagonistic) of EO mixtures by calculation of Combination index (CI) and Dose-reduction index (DRI). Among the individual and mixture of two EOs, cinnamon EO and cinnamon EO + lemon grass EO combination showed highest acaricidal activity against R. (B.) microplus larvae. Further, the combination of cinnamon EO + lemon grass EO showed high synergism with CI value of 0.381, followed by cinnamon EO + clove EO showing moderate synergism whereas, clove EO + lemon grass EO showed only additive effect, with favorable dose reduction for each constituent drug in all three combinations. The combination of all three EOs (1:1:1) showed high synergism (CI value of 0.376) and favorable dose reduction (DRI index of 8.19, 25.64 and 4.64 for clove, cinnamon and lemon grass EOs, respectively) against R. (B.) microplus larvae.

Acaricidal activity, biochemical effects and molecular docking of some monoterpenes against two-spotted spider mite (Tetranychus urticae Koch).

Six natural monoterpenes (1,8-cineole, (-)-citronellal, limonene, α-pinene, pulegone and 4-terpineol) showed high acaricidal activity by fumigant and contact actions against adult females of the two-spotted spider mite, Tetranychus urticae Koch. The monoterpenes exhibited varying degrees of acaricidal potency using contact toxicity test after 24 and 48 h of treatment, where the LC50 values were <160 and 45 mg/L, respectively. In fumigation test, of these six monoterpenes, pulegone exhibited the highest toxicity (LC50 = 3.81 mg/L air), while (-)-citronellal had the lowest fumigant toxicity (LC50 = 15.20 mg/L air). All compounds had high inhibitory effect on acetylcholinesterase (AChE) and gama amino butyric acid transaminase (GABA-T) activities. Pulegone was the most AChE inhibitor (IC50 = 8.79 mg/L), while 4-terpineol revealed the lowest inhibitory effect (IC50 = 32.82 mg/L). However, limonene caused the highest inhibition of GABA-T (IC50 = 11.37 mg/L). The molecular docking studies revealed that the compounds displayed different binding interactions with the amino acid residues at the catalytic sites of AChE and GABA-T enzymes. Noncovalent interactions especially van der Waals, hydrogen bonding as well as hydrophobic was found between the compounds and the enzymes. A significant relationship was found between the docking score and the biological activity of monoterpenes compared to the standard acaricide pyridaben. In silico ADMET properties were also performed and displayed potential for the development of good acaricidal candidates.

Chemical profile, characterization and acaricidal activity of essential oils of three plant species and their nanoemulsions against Tyrophagus putrescentiae, a stored-food mite.

Essential oils of Ocimum basilicum (L.), Achillea fragrantissima (Forssk.) and Achillea santolina (L.) were obtained by hydrodistillation and analyzed using gas chromatography (GC) and GC/mass spectrometry (MS). Oil-in-water nanoemulsions (10% active ingredient) were prepared through a high-energy (ultrasonication) emulsification process. Nanoemulsions were characterized by viscosity, pH, thermodynamic stability, droplet size, polydispersity index (PDI) and scanning electron microscopy (SEM) measurements. The plant oils and their nanoemulsions showed considerable acaricidal activity against the mold mite, Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae). In a contact toxicity bioassay and 48 h post treatment, O. basilicum oil was the most toxic, followed by A. fragrantissima and A. santolina, where LC50 values were 8.4, 14.1 and 21.8 µl/cm2, respectively. LC50 for benzyl benzoate, a standard acaricide was 9.8 µl/cm2. Upon fumigation, responses also varied according to the test oil. Based on the 48-h LC50 values, the same manner of activity was also observed, where O. basilicum was the most toxic followed by A. fragrantissima and A. santolina. When prepared as nanoemulsions (particle size from 78.5 to 104.6) and tested as fumigants, toxicity of the oils was increased drastically with LC50 values of 2.2, 4.7, and 9.6 µl/l air for O. basilicum, A. fragrantissima and A. santolina, respectively. The oils showed a moderate to strong residual acaricidal activity, where O. basilicum oil was the most effective. The results suggest that appropriate nanoemulsions containing the tested oils can be developed to control T. putrescentiae after the required toxicological assessments.

Toxicity and effects of essential oils and their components on Dermanyssus gallinae (Acari: Dermanyssidae).

The acaricidal activity of 30 essential oils against the poultry red mite, Dermanyssus gallinae, female adults and behavioral responses of the mites to these essential oils were investigated. Cinnamon bark oil and clove bud oil showed 100% acaricidal activity after 24 h in the 1.3 µg/m2 treatment. In addition, four components in cinnamon bark oil and three components in clove bud oil were identified using gas chromatography-mass spectrometry. Cinnamon bark oil showed the highest LD50 value among all of the components, and eugenol showed 0.97-fold higher relative toxicity (RT) than the other components of clove bud oil. The fumigant effects of both essential oils and their seven components were observed using a vapor phase toxicity bioassay. All the substances showed repellent activity except for cinnamyl acetate, which did not show any repellent response even in the > 10 µg treatment. In the experiment using the T-tube olfactometer with the 10 µg treatment of each substance, D. gallinae female adults responded to all the substances except cinnamyl acetate. However, eugenol and eugenol acetate showed an attractant effect after 240 and 120 min of treatment, respectively. These results suggest that the two studied essential oils and their components may be used as control agents against D. gallinae.

Synthesis of novel quinolinomatrine derivatives and their insecticidal/acaricidal activities.

In continuation of our program to discover natural product-based pesticidal agents, a series of new quinolinomatrine derivatives were prepared. Especially three-dimensional structures of five compounds were unambiguously determined by single-crystal X-ray diffraction. Among them, 21-chloroquinolinomatrine exhibited good insecticidal and acaricidal activities against two crop-threatening insect pests, Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.

Synthesis of andrographolide-related esters as insecticidal and acaricidal agents.

In continuation of our program aimed at the development of natural product-based pesticidal agents, a series of andrographolide-related esters, such as 3,19-dialkyl(aryl)carbonyloxy andrographolide (3a-g), 3-alkyl(aryl)carbonyloxyandrographolide (4a-g), and 19-alkyl(aryl)carbonyloxyandrographolide (5a-g), were prepared. Their structures were well characterized by 1H NMR, IR, optical rotation, HRMS and mp. Especially three-dimensional structures of compounds 3a, 4g, and 5g were unambiguously confirmed by single-crystal X-ray diffraction. Compounds 3a and 5a exhibited good insecticidal and acaricidal activities against Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.