New Nortriterpenoid and Ceramides From Stems and Leaves of Cultivated <Emphasis Type="Italic">Triumfetta cordifolia</Emphasis> A Rich (Tiliaceae)

To highlight the role of plants in traditional healing, the leaves and the stems of cultivated Triumfetta cordifolia were phytochemically studied yielding a new nor-ursane type (1), a new ceramide (2) and a new piperidinic ceramide derivative (3) named, respectively, 2α,19α-dihydroxy-3-oxo-23-nor-urs-12-en-28-oic acid, (2R)-2-hydroxy-N-[(2S,3S,4R,26E)-1,3,4-trihydroxy-26-triaconten-2-yl] tetradecanamide and (2R,8Z)-2-hydroxy-{(2S,3R,5R,6S)-3,5-dihydroxy-6-[(1E,5Z)-hexadeca-1,5-dienyl]-2-(β-d-glucopyranosyloxy)methyl piperidine-1-yl} tetracos-8-enamide (3). These were obtained together with lupeol (4), stigmasterol (5), 3-O-β-d-glucopyranoside of β-sitosterol (6), tormentic acid (7) from stems and heptadecanoic acid (8), β-carotene (9), oleanolic acid (10), and 24-hydroxytormentic acid (11) from leaves. The structures were determined on the basis of NMR data (¹H-, ¹³C-, 2D-NMR analyses), mass spectrometry and confirmed by chemical transformations as well as comparison of spectral data with those reported in the literature. The FRAP method was used to evaluate the antioxidant activity of fractions collected from flash chromatography and isolated compounds. Among the fractions, four reduced Fe^III-TPTZ to Fe^II-TPTZ while isolated pure compounds showed no activity.     

Isolation and Phytotoxicity of Terpenes from <Emphasis Type="Italic">Tectona grandis</Emphasis>

A study was carried out on the allelopathic potential of four forest species, Tectona grandis, Aleurites fordii, Gliricidia sepium, and Maytenus buxifolia. The most active species, T. grandis, was selected to perform a phytochemical study. A new compound, abeograndinoic acid, was isolated, and elucidation of its structure showed that this compound has an unusual carbon skeleton. A further 21 known terpenoids—including 4 sesquiterpenoids, 8 diterpenes and 9 triterpenes—also were isolated. A biosynthetic scheme for the presence of the new compound is proposed. Bioactivity profiles that used etiolated wheat coleoptiles and phytotoxicity bioassays on the isolated compounds were conducted. The compounds that presented the highest phytotoxic activity are the diterpenes 9 (2-oxokovalenic acid) and 12 (19-hydroxyferruginol).     

New glyceroglycolipid and ceramide from <Emphasis Type="Italic">Premna microphylla</Emphasis>

Iwo new compounds (1,2) were isolated from the ethanolic extract of the leaves of Premna microphylla, together with five known compounds. The structures of compounds 1 and 2 were elucidated as (2S,3S,4R,11E)-2-[(2R)-2-hydroxytetracosanoylamino]-11-octadecene-1,3,4-triol (1) and 1-O(9Z,12Z, 15Z-octadecatrienoyl)-3-O-[β-d-galactopyranosyl-(1→6)-O-β-d-galactopyranosyl-(1→6)-α-d-galactopyranosyl] glycerol (2) by means of spectroscopic and chemical methods.     

New Sphingolipids with a Previously Unreported 9-Methyl-C<Subscript>20</Subscript>-sphingosine Moiety from a Marine Algous Endophytic Fungus <Emphasis Type="Italic">Aspergillus niger</Emphasis> EN-13

Asperamides A (1) and B (2), a sphingolipid and their corresponding glycosphingolipid possessing a hitherto unreported 9-methyl-C₂₀-sphingosine moiety, were characterized from the culture extract of Aspergillus niger EN-13, an endophytic fungus isolated from marine brown alga Colpomenia sinuosa. The structures were elucidated by spectroscopic and chemical methods as (2S,2′R,3R,3′E,4E,8E)-N-(2′-hydroxy-3′-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (1) and 1-O-β-d-glucopyranosyl-(2S,2′R,3R,3′E,4E,8E)-N-(2′-hydroxy-3′-hexadecenoyl)-9-methyl-4,8-icosadien-1,3-diol (2). In the antifungal assay, asperamide A (1) displayed moderate activity against Candida albicans.     

Contact Sex Pheromone Components of the Seed Beetle, <Emphasis Type="BoldItalic">Callosobruchus analis</Emphasis> (F.)

Callosobruchus analis (Coleoptera: Chrysomelidae: Bruchinae), found throughout tropical Asia and Africa, is a pest of stored legumes. Previous work has shown that females of this species produce a contact sex pheromone that elicits copulatory behavior in males. Comparisons of copulatory activity between any two of four congeneric species suggest that the contact sex pheromones are species specific. In laboratory bioassays, male C. analis exhibited copulatory behavior to a female dummy to which a crude extract of virgin females was applied. The extract had been collected by a filter paper method and was purified by acid–base partition and chromatographic techniques. Gas chromatography-mass spectrometry (GC-MS) analyses of active fractions revealed that the active compounds were 2,6-dimethyloctane-1,8-dioic acid (1) and callosobruchusic acid, (E)-3,7-dimethyl-2-octene-1,8-dioic acid (2), previously identified as contact sex pheromones of Callosobruchus maculatus (F.) and C. chinensis (L.), respectively. The stereoisomeric and chemical compositions were determined by the 2D-HPLC-Ohrui-Akasaka method as (2S,6R)-1:(S)-2 = 1.8:1, which meant that both compounds in C. analis were stereochemically pure, unlike the case of C. maculatus and C. chinensis. An examination of the influence of synthetic pheromone compounds on male copulatory activity revealed that (2S,6R)-1 is the main component, and that (S)-2 has an additive effect. In the examination of the stereochemistry-activity relationship, no copulatory behavior was elicited by (2R,6S)-1, and, furthermore, the enantiomer significantly masked the pheromonal activity of (2S,6R)-1. Glass rod dummy assays also suggested the presence of synergists. These results could elucidate the specificity of mate recognition in C. analis.     

Two Novel Ceramides with a Phytosphingolipid and a Tertiary Amide Structure from <Emphasis Type="Italic">Zephyranthes candida</Emphasis>

Two novel ceramides, Candidamide A (1) with a phytosphingolipid structure, and Candidamide B (2) with a tertiary amide structure, together with 12 known compounds (3–14) have been isolated from the bulbs of Zephyranthes candida, The structures of 1 and 2 have been elucidated to be 1,3,5,6-tetrahydroxy-2-(2′-hydroxytetracosanoyl amino)-8-(E)-octadecadiene (1) and (2S,3S,4R,8E,2′R)-2-[N-(2′-hydroxyoctadecanoyl)-N-(1′′,2′′-dihydroxyethyl)-amino]-8-hexacosene-1,3,4-triol (2) on the basis of spectroscopic evidence including IR, MS, NMR (¹H-NMR, ¹³C-NMR, DEPT, ¹H–¹H COSY, HSQC, HMBC). The known compounds were identified as (2S)-3′,7-dihydroxy-4′-methoxyflavan (3), (2S)-4′-hydroxy-7-methoxyflavan (4), (2S)-4′,7-dihydroxyflavan (5), 7-hydroxy-3′, 4′-methylenedioxyflavan (6), ambrettolide (7), β-sitostero1 (8), β-daucosterin (9), rutin (10), pancratistatin (11), lycorine (12), haemanthidine (13), and haemanthamine (14). In the antimicrobial assay, candidamide A (1) and candidamide B (2) displayed moderate activities against bacteria Staphylococcus aureus and Escherichia coli, and fungi Aspergillus niger, Candida albicans and Trichophyton rubrum.     

From 1-<Emphasis Type="SmallCaps">d</Emphasis> to 3-<Emphasis Type="SmallCaps">d</Emphasis> Supramolecular Structures Derived from Diphenic Acid and Auxiliary Ligands

Four novel compounds [Co(Hdpa) ₂(4,4′-bipy)₂]_n (1), {[Ni(dpa)(2,2′-bipy)(H₂O)](H₂O)}_n, (2), [Ni(dpa)(im)₃]_n (3) and [Zn(dpa)(im)]_n (4) [H₂dpa = 2,4′-diphenyl-dicarboxylic acid, 4,4′-bipy = 4,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine and im = imidazole] were synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. X-ray crystallography shows that the 2,4′-diphenic acid exhibits three coordination modes to link the metal ions: μ ₁ −η¹: η¹/μ ₀ −η⁰: η⁰, μ ₁−η ¹: η ⁰/μ ₂−η ¹: η ¹ and μ ₁−η ¹: η ⁰/μ ₁−η ¹: η ⁰. Compound 1 has a 1D supramolecular structure. Compounds 2 and 3 are 3D supramolecular structures. Compound 4 is a 2D supramolecular structure. All the compounds, 1–4, are self-assembled to form supramolecular structures through hydrogen bonding interactions.     

Pecipamide,a New Sphingosine Derivative from the Cultures of <Emphasis Type="Italic">Polyporus picipes</Emphasis> (Basidiomycetes)

A new C₁₈-ceramide congener named pecipamide (1), together with the known ergosta-4,6,8(14),22-tetraen-3-one (2), was isolated from the solid fermentations of the basidiomycetous fungus Polyporus picipes. The structure of the new metabolite was established as (2′R,2S,3R)-N-2′-hydroxyheptadecanoyl-2-amino-octadecane-1,3-diol on the basis of spectroscopic data, including 1D- and 2D- nuclear magnetic resonance spectroscopy (NMR) experiments, as well as by means of mass spectrometric measurements (MS).     

Metabolites from an Endophytic Fungus <Emphasis Type="Italic">Sphaceloma</Emphasis> sp. LN-15 Isolated from the Leaves of <Emphasis Type="Italic">Melia azedarach</Emphasis>

Two new natural compounds, a symmetrical disulfide dimer didodecyl 3,3″-dithiodipropionate (1) and a pregnane steroid 5,16-pregnadien-3β-ol-20-one acetate (2), were isolated together with two known compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) and ergosterol peroxide (4), from the ethyl acetate soluble extract of fermentation broth of an endophytic fungus, Sphaceloma sp. LN-15 isolated from the leaves of Melia azedarach L. and grown in pure culture. Their structures were determined on the basis of spectroscopic methods including 1D and 2D nuclear magnetic resonance spectroscopy (NMR) experiments and by mass spectrometric measurements (MS). These fungal metabolites were isolated for the first time from the genus Sphaceloma. The structure of 1 was also confirmed by chemical synthesis.     

Constituents of Amomum tsao-ko and their radical scavenging and antioxidant activities

Constituents of the fruit of Amomum tsao-ko were investigated following a preliminary screening of the antioxidant activity of several extracts of the fruit of this plant that showed that the dichloromethane extract and the ethyl acetatesoluble and water-soluble fractions of the 70% aqueous acetone extract had higher activity than α-tocopherol and butylated hydroxytoluene (BHT). Eleven compounds were isolated from the ethyl acetate-soluble fraction, and their structures were elucidated as (+)-hannokinol (1), meso-hannokinol (2), (+)-epicatechin (3), (−)-catechin (4), β-sitosterol (5), β-sitosterol 3-O-glucoside (6), 2,6-dimethoxyphenol (7), protocatechualdehyde (8), protocatechuic acid (9), vanillic acid (10), and p-hydroxybenzoic acid (11) based on mass and various nuclear magnetic resonance (NMR) spectroscopic techniques. This is the first isolation of epicatechin and catechin from the genus Amomum. The radical scavenging activity of the isolated compounds was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and colorimetric and electron spin resonance (ESR) analyses. The antioxidant activity of the compounds was also determined based on the oxidative stability index (OSI). The catechins and catechol derivatives showed strong activities in both the DPPH radical scavenging activity and antioxidant activity assays.     

New ceramides from <Emphasis Type="Italic">Rantherium suaveolens</Emphasis>

A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S, 3S, 4R, 2′R, 14E)-2-(2′-hydroxydocosanoylamino)-14-octadecene-1,3,4-triol (1), (2S,3S,4R,2′R, 14F)-2-(2′-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol (2), (2S,3S,4R,2′R,14F)-2-(2′-hydroxytetracosanoylamino)-14-octadecene-1,3,4-triol (3), (2S,3S,4R,2′R,14E)-2-(2′-hydroxypentacosanoylamino)-14-octadecene-1,3,4-triol (4), and (2S,3S,4R,2′R,14E)-2-(2′-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol (5).     

New cerebrosides from the basidiomycete <Emphasis Type="Italic">Cortinarius tenuipes</Emphasis>

Five cerebrosides (1–5), including three new ones named cortenuamide A (1), cortenuamide B (2), and cortenuamide C (3), were isolated from the fruiting bodies of the basid-iomycete Cortinarius tenuipes. The structures of those compounds were elucidated as (4E,8E)-N-d-2′-hydroxytetracosanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (1), (4E,8E)-N-d-2′-hydroxytricosanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8 sphingadienine (2), (4E, 8E)-N-d-2′-hydroxydocosanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (3), (4E, 8E)-N-d-2′-hydroxyoctadecanoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (4), and (4E, 8E)-N-d-2′-hydroxypalmitoyl-1-O-β-d-glycopyranosyl-9-methyl-4,8-sphingadienine (5) by spectral and chemical methods.     

Synthesis and surface properties of chemodegradable anionic surfactants: Diastereomeric (2-n-alkyl-1,3-dioxan-5-yl) sulfates with monovalent counter-ions

Sodium, potassium and ammonium cis- and trans-(2-n-alkyl-1,3-dioxan-5-yl) sulfates 6–8 (alkyl: n-C₉H₁₉, 6a–8a, and n-C₁₁H₂₃, 6b–8b) were synthesized in a reaction of aliphatic aldehydes 1a,b with glycerol 2 followed by separation in high yields of individual geometric isomers of cis-and trans-2-n-alkyl-5-hydroxy-1,3-dioxanes, cis-3a,b and trans-3a,b, followed by sulfation with sulfur trioxide-pyridine complex, and finally neutralization with NaOH, KOH, and NH₄OH, respectively. Physical data of the compounds and some surface properties of 2-n-nonyl derivatives, such as critical micelle concentration (CMC), effectiveness of aqueous surface tension reduction (Π_CMC), surface excess concentration Γ_CMC, and the surface area demand per molecule (A_CMC), were determined. It was shown that the surface activity of these compounds is influenced both by their geometric structure and by the monovalent counter-ion.     

Novel ceramides and a new glucoceramide from the roots of <Emphasis Type="Italic">Incarvillea arguta</Emphasis>

Novel ceramides, rel-(3S,4S,5S)-3-[(2R)-2-hydroxycosanoyl-hexacosanoylamino]-4-hydroxy-5-[(4Z)-tetradecane-4-ene]-2,3,4,5-tetrahydrofuran (1a-g), and a new glucoceramide, 1-O-β-d-glucopyranosyl-(2S,3S,4R,8E)-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-octodecanetriol-8-ene (2) were isolated from the aqueous ethanolic extract of the roots of Incarvillea arguta, together with eight known compounds: β-sitosterol (3), oleanolic acid (4), ursolic acid (5), piperin (6), maslinic acid (7), β-sitosterol 6′-O-acyl-β-d-glucopyranoside (8), 8-epideoxyloganic acid (9), and plantarenaloside (10). Their structures were elucidated on the basis of spectral data including IR, MS, NMR [¹H NMR, ¹³C NMR (distortionless enhancement by polarization transfer), ¹H−¹H COSY, heteronuclear multiplequantum coherence, and heteronuclear multiple-bond coherence correlations]. The relative configurations were established by nuclear Overhauser effect spectroscopy experiments and by comparison of the NMR spectral data and coupling constants with those already reported in the literature.     

A new route to steroid ring C aromatization from readily available precursors

3β-Acetoxy-8α,9α-epoxy-5α-cholest-14-ene (1); 3β-acetoxy-14α,15α-epoxy-5α-cholest-8-ene (2); 3β-acetoxy-5α-cholest-8(14)-ene-9α,15α-diol (3); and 3β-acetoxy-5α-cholesta-8(14),9(11)-dien-15α-ol (4) have been aromatized to a 9∶1 mixture of 3β-hydroxy-12-methyl-18-nor-5α,17β(H)-cholesta-8,11,13-triene (5a) and 3β-hydroxy-12-methyl-18-nor-5α,17α(H)-cholesta-8,11,13-triene (5b) in ethanol solution by using hydrochloric acid. The aromatization by action ofp-toluenesulfonic acid gave mainly the epimer with the natural C-17 configuration as the acetate 5c at the appropriatep-toluenesulfonic acid concentration. 3β-Acetoxy-5α-cholesta-7,9(11),14-triene (7a) and 3β-hydroxy-5α-cholesta-8,11,14-triene (8a), 2 intermediary compounds in the aromatization, were isolated and characterized.     

A new glucoceramide from the watermelon begonia, <Emphasis Type="Italic">Pellionia repens</Emphasis>

A new glucoceramide named pellioniareside (1) was isolated from the aqueous ethanolic extract of whole plants of Pellionia repens, together with lupeol (2), uracil (3), (22E,20S,24R)-5α,8α-epidioxyergosta-6,22-dien-3-β-ol (4), and daucosterol (5). The structure and relative configurations of pellioniareside were identified as (2S,3S,4R,6E,8E)-1-O-β-d-glucopyranosyl-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-octadecanetriol-6,8-diene by analysis of spectral data and by chemical evidence.     

Fumigant and Contact Toxicities of Monoterpenes to <Emphasis Type="Italic">Sitophilus oryzae</Emphasis> (L.) and <Emphasis Type="Italic">Tribolium castaneum</Emphasis> (Herbst) and their Inhibitory Effects on Acetylcholinesterase Activity

A comparative study was conducted to assess the contact and fumigant toxicities of eleven monoterpenes on two important stored products insects—, Sitophilus oryzae, the rice weevil, and Tribolium castaneum, the rust red flour beetle. The monoterpenes included: camphene, (+)-camphor, (−)-carvone, 1-8-cineole, cuminaldehyde, (l)-fenchone, geraniol, (−)-limonene, (−)-linalool, (−)-menthol, and myrcene. The inhibitory effect of these compounds on acetylcholinesterase (AChE) activity also was examined to explore their possible mode(s) of toxic action. Although most of the compounds were toxic to S. oryzae and T. castaneum, their toxicity varied with insect species and with the bioassay test. In contact toxicity assays, (−)-carvone, geraniol, and cuminaldehyde showed the highest toxicity against S. oryzae with LC₅₀ values of 28.17, 28.76, and 42.08 μg/cm², respectively. (−)-Carvone (LC₅₀ = 19.80 μg/cm²) was the most effective compound against T. castaneum, followed by cuminaldehyde (LC₅₀ = 32.59 μg/cm²). In contrast, camphene, (+)-camphor, 1-8-cineole, and myrcene had weak activity against both insects (i.e., LC₅₀ values above 500 μg/cm²). In fumigant toxicity assays, 1-8-cineole was the most effective against S. oryzae and T. castaneum (LC₅₀ = 14.19 and 17.16 mg/l, respectively). Structure-toxicity investigations revealed that (−)-carvone—, a ketone—, had the highest contact toxicity against the both insects. 1-8-Cineole—, an ether—, was the most potent fumigant against both insects. In vitro inhibition studies of AChE from adults of S. oryzae showed that cuminaldehyde most effectively inhibited enzyme activity at the two tested concentrations (0.01 and 0.05 M) followed by 1-8-cineole, (−)-limonene, and (l)-fenchone. 1-8-Cineole was the most potent inhibitor of AChE activity from T. castaneum larvae followed by (−)-carvone and (−)-limonene. The results of the present study indicate that (−)-carvone, 1,8-cineole, cuminaldehyde, (l)-fenchone, and (−)-limonene could be effective biocontrol agents against S. oryzae and T. castaneum.     

A new ceramide from the basidiomycete Russula cyanoxantha

A new phytosphingosine-type ceramide (1) was isolated along with nine other compounds—5α,8α-epidioxy-(22E,24R)-ergosta-6,22-dien-3β-ol, 5α,8α-epidioxy-(24S)-ergosta-6-en-3β-ol, (24S)-ergosta-7-ene-3β,5α,6β-triol,(22E,24R)-ergosta-7, 22-dien-3β,5α,6β-triol, inosine, adenine, l-pyroglutamic acid, fumaric acid, and d-allitol from the ethanol and chloroform/methanol extract of the fruiting bodies of the basidiomycete Russula cyanoxanotha (Schaeff.) Fr. The structure of (1) was established as (2S,3S,4R,2′R)-2-(2′-hydroxytetracosanoylamino) octadecane-1,3,4-triol by means of spectroscopic and chemical methods.     

Synthesis and <Emphasis Type="Italic">in vitro</Emphasis> cytotoxic activity of N-, F-, and S-ether derivatives of podophyllotoxin fatty acid adducts

This paper represents the first synthesis, spectroscopic characterization, and antitumor evaluation of F-, N-, and S-containing C₄α-FA derivatives of podophyllotoxin. In a synthetic strategy, a FA unit of 4-O-podophyllotoxinyl 12-hydroxyoctadec-Z-9-enoate 2, a derivative of podophyllotoxin, was functionalized at the C−12 position by incorporating the F atom and N-containing moieties. The FA olefin (Z, C−9/C−10) of 2 was hydrogenated to produce a derivative possessing a hydroxy function (C−12) on a saturated C₁₈ FA chain. In another synthetic strategy, two S-ethers of podophyllotoxin (C₄α) were synthesized from a terminal unsaturated FA analog, 4-O-podophyllotoxinyl undec-10-enoate. Syntheses were achieved through effective synthetic procedures; ¹H NMR, ¹³C NMR, IR, and high-resolution mass data proved excellent tools to characterize these derivatives. In vitro antitumor activity was investigated against a panel of five human neoplastic cell lines, SK-MEL (malignant, melanoma), KB (epidermal carcinoma, oral), BT-549 (ductal carcinoma, breast), SK-OV-3 (ovary carcinoma), and HL-60 (human leukemia). Keeping in view the severe lack of tumor selectivity of podophyllotoxin over normal cells, we assayed new analogs against noncancerous mammalian VERO (African green monkey kidney fibroblast) cell lines to gauge their extent of toxicity. Several of these compounds showed excellent moderation of antitumor activity. In general, we found excellent growth inhibition against the human leukemia cell line (HL-60), particularly for the analogs containing S-ethers and carbamates. None of the compounds were toxic to normal cell lines.     

Enantiospecific Effect of Pulegone and Pulegone-Derived Lactones on Myzus persicae (Sulz.) Settling and Feeding

The effect of pulegone chiral center configuration on its antifeedant activity to Myzus persicae was examined. Biological consequences of structural modifications of (R)-(+)- and (S)-(−)-pulegone, the lactonization, iodolactonization, and incorporation of hydroxyl and carbonyl groups were studied, as well. The most active compounds were (R)-(+)-pulegone (1a) and δ-hydroxy-γ-spirolactones (5S,6R,8S)-(−)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (5b) and (5R,6S,8S)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (6b) derived from (S)-(−)-pulegone (1b). The compounds deterred aphid probing and feeding at preingestional, ingestional, and postingestional phases of feeding. The preingestional effect of (R)-(+)-pulegone (1a) was manifested as difficulty in finding and reaching the phloem (i.e., prolonged time preceding the first contact with phloem vessels), a high proportion of probes not reaching beyond the mesophyll layer before first phloem phase, and/or failure to find sieve elements by 20% of aphids during the 8-hr experiment. The ingestional activity of (R)-(+)-pulegone (1a) and hydroxylactones 5b and 6b resulted in a decrease in duration of phloem sap ingestion, a decrease in the proportion of aphids with sustained sap ingestion, and an increase in the proportion of aphid salivation in phloem. δ-Keto-γ-spirolactone (5R,8S)-(−)-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2,6-dione (8b) produced a weak ingestional effect (shortened phloem phase). The postingestional deterrence of (R)-(+)-pulegone (1a) and δ-hydroxy-γ-spirolactones (5R,6S,8R)-(+)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]-decan-2-one (5a), 5b, (5S,6R,8R)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (6a), 6b, and δ-keto-γ-spirolactone 8b prevented aphids from settling on treated leaves. The trans position of methyl group CH₃–8 and the bond C5–O1 in lactone 6b appeared to weaken the deterrent activity in relation to the cis diastereoisomer (5b).