Jhon Patar | Stikes Medistra (original) (raw)

Natural Product of Organic Chemistry by Jhon Patar

Papers by Jhon Patar

Jurnal Sains dan Kesehatan

Determination of phenolic content using uv-visible and measured IC50 as antioxidant of saputangan... more Determination of phenolic content using uv-visible and measured IC50 as antioxidant of saputangan leaves. Methods: Screening was used FeCl3, NH3, Alkali and Pb(CH3COO)2. The maceration process was carried out using ethanol as a solvent and soaked for more than 24 hours. The measurement of total flavonoid levels began with determining the maximum wavelength of quercetin, which was 442 nm. The linear regression equation for the resulting quercetin calibration curve was the equation y = 0.0155x + 0.0387 with a correlation value (R2) of 0.9943. The linear regression of antioxidant of saputangan leaves on percentage of inhibition is y = 0.6899x + 1.5616 with a correlation (R2) of 0.9895. The Maniltoa grandiflora (A. Gray) Scheff leaves contained flavonoid compounds which are proven based on the results of screening. Meanwhile, the weight of the extract after partitioning using ethyl acetate and n-hexane was 50 gr. Total flavonoid levels in Maniltoa grandiflora (A. Gray) Scheff leaves wer...

Universitas Sumatera Utara, 2018

JURNAL FARMASIMED (JFM), 2021

Phytochemical screening test proved that the extract of Reeds (Imperata cylindrica) contained phe... more Phytochemical screening test proved that the extract of Reeds (Imperata cylindrica) contained phenolic compounds tested using 5% FeCl3 reagent. Antibacterial test using agar diffusion method against Reeds extract in DMSO solvent. The phenolic compounds obtained from the saputangan leaves Reeds extract were 36.96 grams after undergoing maceration. Reeds extract of phenolic compounds with concentrations (200; 100; 50 and 25 ppm) had strength antibacterial where the average inhibition zone of Staphylococcus aureus bacteria was 10.0 mm and the average inhibition zone was at Escherichia coli bacteria measuring 10.3 mm.

Proceedings of the International Conference on Health Informatics and Medical Application Technology, 2019

Phytochemical screening test used 5% FeCl 3 reagent showed extract become to black extract that s... more Phytochemical screening test used 5% FeCl 3 reagent showed extract become to black extract that saputangan leaves contained phenolic compound. Saputangan leaves powder was macerated with methanol and got macerate as 100.84 g. Macerate was dissolved with aquadest to remove lipid in saputangan leaves. First partition was used ethyl acetate to get solid extract as 37.03 g. Second Partition was used n-hexane to get solid extract as 18.25 g. Total phenolic was analysed on plate of thin layer chromatography with used chloroform and methanol with 70:30 comparison. Total phenolic has 3 spots that have an Rf of 0.44 ; 0.29 and 0.22. Total phenolic absorbance measured at 516 nm wavelength using a UV-Visible spectrophotometer. Total phenolic solutions were soluted in concentrations of 10, 25 and 50 ppm using methanol p.a as solvent. The absorbance obtained at all three concentrations was 0.202; 0.195 and 0.175. Based on the linear regression equation Y = 1,191 X + 31.87, the IC50 value for the total phenolic was 15.22 ppm. IC50 value of 15.22 ppm can be categorized as a total phenolic compound as a strong antioxidant.

JURNAL PENGMAS KESTRA (JPK), 2021

One of the fruits in Indonesia that can be used in the cosmetic sector is watermelon. Its red col... more One of the fruits in Indonesia that can be used in the cosmetic sector is watermelon. Its red color indicates the high content of lycopene, a natural pigment as a coloring agent in decorative cosmetic formulations, especially blusher. The purpose of this study was to determine whether watermelon extract can be used as a dye in blusher preparations and to determine the formulation of watermelon (Citrullus lanatus) blusher does not cause skin irritation when used. The extract was obtained by maceration using 96% ethanol. The blush formula uses dye from watermelon with a concentration of 15%, 20%, and 25%. The evaluation of preparations includes homogeneity, organoleptic, irritation test, pH test. The results showed that homogeneity, organolepti, and pH of the preparation remained stable for 14 days of storage. The results of the irritation test did not show any irritation.

JURNAL PENGMAS KESTRA (JPK), 2021

Jackfruit leaf is (Artocarpus heterophyllus L) is one of the natural ingredients that can be used... more Jackfruit leaf is (Artocarpus heterophyllus L) is one of the natural ingredients that can be used as a therapeutic treatment of acne. To facilitate is use the extract is made in the form of a cream. This study aims to determine the antibacterial activity of anti-acne cream jackfruit leaf extract against propionibacterium acne with concentrations of 30%, 50%, 70%, and 90%. Compounds that act as antibacterials on jackfruit leaves include flavonoids, tannins, saponins. This research method is an ANOVA one way method. The extraction method used is the maceration method. The tests include physical stability test and anti-acne activity test. Physical preparation stability test is carried out every 6 days for 3 weeks. While the anti acne activity observation test was carried out on bacteria of Propionibacterium acne. Based on organoleptic observation got formulations 1 and 2 there was no change, while 3,4,5 there was a change. Anti acne activity test showed that formulations 1 and 2 were m...

Jurnal Prima Medika Sains, 2021

Latar belakang: Kedelai adalah hasil pangan jenis kacang-kacangan yang sangat kaya akan nutrisi y... more Latar belakang: Kedelai adalah hasil pangan jenis kacang-kacangan yang sangat kaya akan nutrisi yang bermanfaat bagi kesehatan manusia. Tujuan: Untuk mengetahui keberadaan zat besi dan kadar zat besi dalam sari kedelai. Metode: Analisis kualitatif menggunakan pereaksi NaOH, K4[Fe(CN)6] dan K3[Fe(CN)6] dan analisis kuantitatif menggunakan spektrofotometer UV-Visibel pada panjang gelombang 248.3 nm. Hasil: Sari kedelai mengandung zat besi yang dibuktikan melalui analisis kualitatif menggunakan pereaksi NaOH, K4[Fe(CN)6] dan K3[Fe(CN)6] yang menghasilkan masing-masing endapan hijau, biru dan coklat yang artinya mengnadung zat besi. Persamaan regresi linear larutan standar besi adalah Y = 0.0154x + 0.1555 dengan korelasi (R2) sebesar 0.9981. Kadar zat besi dalam sari kedelai adalah 56.48 mg/ml dan termasuk dalam kelompok produk yang memiliki kadar zat besi yang cukup tinggi. Kesimpulan: Sari kedelai mengandung zat zat besi dengan kadar sebesar 56.48mg/ml.

Stannum : Jurnal Sains dan Terapan Kimia, 2020

Terpenoids screening were carried out using Liebermann Burchard and Salkowski reagent on the extr... more Terpenoids screening were carried out using Liebermann Burchard and Salkowski reagent on the extract of Saputangan leaves. It showed that the leaves contained terpenoid compounds with appeared of a reddish brown ring in the extract and a reddish brown stain appeared on the TLC plate tested with 1% CeSO4 reagent in 10% H2SO4. The macerate of saputangan leaves processed separation using the partition method (Liquid-liquid Extraction). Extracts dissolved with methanol were partitioned with n-Hexane and then partitioned between aquadest and ethyl acetate in a ratio of 1: 1 to obtain 50 g of total terpenoids. Furthermore, TLC analysis was performed on total terpenoids using n-hexane: ethyl acetate (80:20 v/v) solvent to obtain 11 separate stains on the TLC plate with different Rf each. Analysis was enhanced in HPLC using 100% acetonitrile and 0.1% phosphoric acid at a wavelength of 210 nm, a flow rate of 0.500 mL/min and eluted for 30 minutes. Based on the HPLC results, there were 25 pea...

Stannum : Jurnal Sains dan Terapan Kimia, 2020

Natural products can be used as an alternative in the treatment of various diseases such as infec... more Natural products can be used as an alternative in the treatment of various diseases such as infectious diseases due to the bioactive compounds contained therein. Moreover nowdays, there are many antibiotic resistance in the treatment of infectious diseases. Citrus maxima is one of the natural products. Citrus maxima have been used for many diseases in traditional medicine.The aim of this study was to investigate the antibacterial activity of flavonoid-rich fractions of citrus maxima peel extract. The bioactive compounds contained in Citrus maxima peel were extracted by maceration method using 96% ethanol solvent. Fractionation was conducted using liquid-liquid extraction using a solvent of water and ethyl acetate obtained ethyl acetate fraction. In this fraction, the TLC test was carried out to confirm the presence of phenolic and flavonoid compounds. The antibacterial activity testing for ethyl acetate fraction against S.aureus and E.coli was determined by disk diffusion method ...

International Journal of Current Research in Chemistry and Pharmaceutical sciences, 2020

The chemical compound content of green apple juice was pactin, which wass a group of polysacchari... more The chemical compound content of green apple juice was pactin, which wass a group of polysaccharides that can lower cholesterol levels. In addition, there were also several secondary metabolites, including flavonoids, glycosides and triterpenoids. To determine the effect of giving green apple juice on the blood cholesterol levels of guinea pigs treated with hypercholesterolemia by giving food mixed with 15% European chicken egg yolk, 15% goat fat, 20 grams of feed for 6 days. The study was divided into 5 groups (A, a, b, c and S) measured cholesterol levels, group A was given aquadest orally (negative control), groups a, b, c were given green apple juice orally at a dose of 2.03 grams / kg BW, dose 4.06 gram / kg BW, 6.09 gram / kg BW, group S was given 0.01% simvastatin suspension at a dose of 0.775 mg / kg BW orally as a positive control for 14 days. Based on the results of the research tested using statistics, it was obtained that the administration of green apple juice at a dose...

JURNAL FARMASIMED (JFM), 2019

ABSTRAK Herba binara (Artemisia Annua) is one of the plants that contains flavonoids which are ef... more ABSTRAK Herba binara (Artemisia Annua) is one of the plants that contains flavonoids which are efficacious as antioxidants and anticancer. The purpose of this study was to determine the total flavonoid compounds contained in ethanol extract of binara herbs (Artemisia Annua). Compounds in ethanol extract of binara herbs were identified by phytochemical screening. The results showed that the ethanol extract of binara herbs contained alkaloids, flavonoids, saponins, and tannins. Extraction was carried out in two stages, namely maceration stage with 96% ethanol and fat removal stage by hydrolysis using distilled water solvent. The extract was partitioned with ethyl acetate and n-hexane solvents, then the partitions were examined by TLC using the mobile phase of chloroform and ethyl acetate (7: 3). Ribbon patches that have the same Rf and color prices as the initial detection are taken and searched. Then analyzed using High Performance Liquid Chromatography (HPLC). Based on the wavelengt...

Jurnal Penelitian Farmasi & Herbal, 2019

The Phytochemical screening test to identify secondary metabolites of Saputangan leaves extract (... more The Phytochemical screening test to identify secondary metabolites of Saputangan leaves extract (Maniltoa grandiflora (A.Gray) Scheff) showed positive results on phenolic and terpenoid compounds. The reagent used for phenolic screening was 5% FeCl3 and reagent for screening terpenoid was 1% CeSO4 in 10% H2SO4. Antibacterial test was carried out by agar diffusion method on extracts of DMSO Saputangan leaves. Phenolic compound obtained from extract of Saputangan leaves were 36.96 gram where the result was obtained after maceration, partitioning and evaporation processes. Antibacterial of phenolic compound was observed based on inhibitory zone diameters of phenolic compounds formed using paper discs with a diameter of 6 mm. The diameters of the inhibition zone against Escherichia coli bacteria are 8.1; 8.5 and 9.7 mm larger than the diameter of the inhibition zone in Staphylococcus aureus bacteria at 7.3; 7.8 and 8.5 mm. Then it can be stated that DMSO extracts of phenolic compound wit...

JURNAL PENGMAS KESTRA (JPK), 2021

Saputangan leaves contained terpenoids which appeared reddish brown rings when tested using Lieb... more Saputangan leaves contained terpenoids which appeared reddish brown rings when tested using Liebermann Burchard, Salkowski and cerric sulfate. Saputangan leaves were macerated, then partitioned to obtain total terpenoids using a separatory funnel while checking filtrate partition with cerric sulfate. Extracts dissolved with methanol were partitioned with n-Hexane and then partitioned between aquadest and ethyl acetate in a ratio of 1: 1 to obtain 50 g of total terpenoids. TLC analyses was performed on total terpenoids using n-hexane: acetone (80:20 v/v) solvent. The total terpenoids were proved that terpenoids have 11 terpenoids as red stain based on their Rf. Based on the results of tests conducted on participants involved in socialization, it was stated that around 98% of participants had understood terpenoid compounds.

Jurnal Sains dan Kesehatan

Determination of phenolic content using uv-visible and measured IC50 as antioxidant of saputangan... more Determination of phenolic content using uv-visible and measured IC50 as antioxidant of saputangan leaves. Methods: Screening was used FeCl3, NH3, Alkali and Pb(CH3COO)2. The maceration process was carried out using ethanol as a solvent and soaked for more than 24 hours. The measurement of total flavonoid levels began with determining the maximum wavelength of quercetin, which was 442 nm. The linear regression equation for the resulting quercetin calibration curve was the equation y = 0.0155x + 0.0387 with a correlation value (R2) of 0.9943. The linear regression of antioxidant of saputangan leaves on percentage of inhibition is y = 0.6899x + 1.5616 with a correlation (R2) of 0.9895. The Maniltoa grandiflora (A. Gray) Scheff leaves contained flavonoid compounds which are proven based on the results of screening. Meanwhile, the weight of the extract after partitioning using ethyl acetate and n-hexane was 50 gr. Total flavonoid levels in Maniltoa grandiflora (A. Gray) Scheff leaves wer...

Universitas Sumatera Utara, 2018

JURNAL FARMASIMED (JFM), 2021

Phytochemical screening test proved that the extract of Reeds (Imperata cylindrica) contained phe... more Phytochemical screening test proved that the extract of Reeds (Imperata cylindrica) contained phenolic compounds tested using 5% FeCl3 reagent. Antibacterial test using agar diffusion method against Reeds extract in DMSO solvent. The phenolic compounds obtained from the saputangan leaves Reeds extract were 36.96 grams after undergoing maceration. Reeds extract of phenolic compounds with concentrations (200; 100; 50 and 25 ppm) had strength antibacterial where the average inhibition zone of Staphylococcus aureus bacteria was 10.0 mm and the average inhibition zone was at Escherichia coli bacteria measuring 10.3 mm.

Proceedings of the International Conference on Health Informatics and Medical Application Technology, 2019

Phytochemical screening test used 5% FeCl 3 reagent showed extract become to black extract that s... more Phytochemical screening test used 5% FeCl 3 reagent showed extract become to black extract that saputangan leaves contained phenolic compound. Saputangan leaves powder was macerated with methanol and got macerate as 100.84 g. Macerate was dissolved with aquadest to remove lipid in saputangan leaves. First partition was used ethyl acetate to get solid extract as 37.03 g. Second Partition was used n-hexane to get solid extract as 18.25 g. Total phenolic was analysed on plate of thin layer chromatography with used chloroform and methanol with 70:30 comparison. Total phenolic has 3 spots that have an Rf of 0.44 ; 0.29 and 0.22. Total phenolic absorbance measured at 516 nm wavelength using a UV-Visible spectrophotometer. Total phenolic solutions were soluted in concentrations of 10, 25 and 50 ppm using methanol p.a as solvent. The absorbance obtained at all three concentrations was 0.202; 0.195 and 0.175. Based on the linear regression equation Y = 1,191 X + 31.87, the IC50 value for the total phenolic was 15.22 ppm. IC50 value of 15.22 ppm can be categorized as a total phenolic compound as a strong antioxidant.

JURNAL PENGMAS KESTRA (JPK), 2021

One of the fruits in Indonesia that can be used in the cosmetic sector is watermelon. Its red col... more One of the fruits in Indonesia that can be used in the cosmetic sector is watermelon. Its red color indicates the high content of lycopene, a natural pigment as a coloring agent in decorative cosmetic formulations, especially blusher. The purpose of this study was to determine whether watermelon extract can be used as a dye in blusher preparations and to determine the formulation of watermelon (Citrullus lanatus) blusher does not cause skin irritation when used. The extract was obtained by maceration using 96% ethanol. The blush formula uses dye from watermelon with a concentration of 15%, 20%, and 25%. The evaluation of preparations includes homogeneity, organoleptic, irritation test, pH test. The results showed that homogeneity, organolepti, and pH of the preparation remained stable for 14 days of storage. The results of the irritation test did not show any irritation.

JURNAL PENGMAS KESTRA (JPK), 2021

Jackfruit leaf is (Artocarpus heterophyllus L) is one of the natural ingredients that can be used... more Jackfruit leaf is (Artocarpus heterophyllus L) is one of the natural ingredients that can be used as a therapeutic treatment of acne. To facilitate is use the extract is made in the form of a cream. This study aims to determine the antibacterial activity of anti-acne cream jackfruit leaf extract against propionibacterium acne with concentrations of 30%, 50%, 70%, and 90%. Compounds that act as antibacterials on jackfruit leaves include flavonoids, tannins, saponins. This research method is an ANOVA one way method. The extraction method used is the maceration method. The tests include physical stability test and anti-acne activity test. Physical preparation stability test is carried out every 6 days for 3 weeks. While the anti acne activity observation test was carried out on bacteria of Propionibacterium acne. Based on organoleptic observation got formulations 1 and 2 there was no change, while 3,4,5 there was a change. Anti acne activity test showed that formulations 1 and 2 were m...

Jurnal Prima Medika Sains, 2021

Latar belakang: Kedelai adalah hasil pangan jenis kacang-kacangan yang sangat kaya akan nutrisi y... more Latar belakang: Kedelai adalah hasil pangan jenis kacang-kacangan yang sangat kaya akan nutrisi yang bermanfaat bagi kesehatan manusia. Tujuan: Untuk mengetahui keberadaan zat besi dan kadar zat besi dalam sari kedelai. Metode: Analisis kualitatif menggunakan pereaksi NaOH, K4[Fe(CN)6] dan K3[Fe(CN)6] dan analisis kuantitatif menggunakan spektrofotometer UV-Visibel pada panjang gelombang 248.3 nm. Hasil: Sari kedelai mengandung zat besi yang dibuktikan melalui analisis kualitatif menggunakan pereaksi NaOH, K4[Fe(CN)6] dan K3[Fe(CN)6] yang menghasilkan masing-masing endapan hijau, biru dan coklat yang artinya mengnadung zat besi. Persamaan regresi linear larutan standar besi adalah Y = 0.0154x + 0.1555 dengan korelasi (R2) sebesar 0.9981. Kadar zat besi dalam sari kedelai adalah 56.48 mg/ml dan termasuk dalam kelompok produk yang memiliki kadar zat besi yang cukup tinggi. Kesimpulan: Sari kedelai mengandung zat zat besi dengan kadar sebesar 56.48mg/ml.

Stannum : Jurnal Sains dan Terapan Kimia, 2020

Terpenoids screening were carried out using Liebermann Burchard and Salkowski reagent on the extr... more Terpenoids screening were carried out using Liebermann Burchard and Salkowski reagent on the extract of Saputangan leaves. It showed that the leaves contained terpenoid compounds with appeared of a reddish brown ring in the extract and a reddish brown stain appeared on the TLC plate tested with 1% CeSO4 reagent in 10% H2SO4. The macerate of saputangan leaves processed separation using the partition method (Liquid-liquid Extraction). Extracts dissolved with methanol were partitioned with n-Hexane and then partitioned between aquadest and ethyl acetate in a ratio of 1: 1 to obtain 50 g of total terpenoids. Furthermore, TLC analysis was performed on total terpenoids using n-hexane: ethyl acetate (80:20 v/v) solvent to obtain 11 separate stains on the TLC plate with different Rf each. Analysis was enhanced in HPLC using 100% acetonitrile and 0.1% phosphoric acid at a wavelength of 210 nm, a flow rate of 0.500 mL/min and eluted for 30 minutes. Based on the HPLC results, there were 25 pea...

Stannum : Jurnal Sains dan Terapan Kimia, 2020

Natural products can be used as an alternative in the treatment of various diseases such as infec... more Natural products can be used as an alternative in the treatment of various diseases such as infectious diseases due to the bioactive compounds contained therein. Moreover nowdays, there are many antibiotic resistance in the treatment of infectious diseases. Citrus maxima is one of the natural products. Citrus maxima have been used for many diseases in traditional medicine.The aim of this study was to investigate the antibacterial activity of flavonoid-rich fractions of citrus maxima peel extract. The bioactive compounds contained in Citrus maxima peel were extracted by maceration method using 96% ethanol solvent. Fractionation was conducted using liquid-liquid extraction using a solvent of water and ethyl acetate obtained ethyl acetate fraction. In this fraction, the TLC test was carried out to confirm the presence of phenolic and flavonoid compounds. The antibacterial activity testing for ethyl acetate fraction against S.aureus and E.coli was determined by disk diffusion method ...

International Journal of Current Research in Chemistry and Pharmaceutical sciences, 2020

The chemical compound content of green apple juice was pactin, which wass a group of polysacchari... more The chemical compound content of green apple juice was pactin, which wass a group of polysaccharides that can lower cholesterol levels. In addition, there were also several secondary metabolites, including flavonoids, glycosides and triterpenoids. To determine the effect of giving green apple juice on the blood cholesterol levels of guinea pigs treated with hypercholesterolemia by giving food mixed with 15% European chicken egg yolk, 15% goat fat, 20 grams of feed for 6 days. The study was divided into 5 groups (A, a, b, c and S) measured cholesterol levels, group A was given aquadest orally (negative control), groups a, b, c were given green apple juice orally at a dose of 2.03 grams / kg BW, dose 4.06 gram / kg BW, 6.09 gram / kg BW, group S was given 0.01% simvastatin suspension at a dose of 0.775 mg / kg BW orally as a positive control for 14 days. Based on the results of the research tested using statistics, it was obtained that the administration of green apple juice at a dose...

JURNAL FARMASIMED (JFM), 2019

ABSTRAK Herba binara (Artemisia Annua) is one of the plants that contains flavonoids which are ef... more ABSTRAK Herba binara (Artemisia Annua) is one of the plants that contains flavonoids which are efficacious as antioxidants and anticancer. The purpose of this study was to determine the total flavonoid compounds contained in ethanol extract of binara herbs (Artemisia Annua). Compounds in ethanol extract of binara herbs were identified by phytochemical screening. The results showed that the ethanol extract of binara herbs contained alkaloids, flavonoids, saponins, and tannins. Extraction was carried out in two stages, namely maceration stage with 96% ethanol and fat removal stage by hydrolysis using distilled water solvent. The extract was partitioned with ethyl acetate and n-hexane solvents, then the partitions were examined by TLC using the mobile phase of chloroform and ethyl acetate (7: 3). Ribbon patches that have the same Rf and color prices as the initial detection are taken and searched. Then analyzed using High Performance Liquid Chromatography (HPLC). Based on the wavelengt...

Jurnal Penelitian Farmasi & Herbal, 2019

The Phytochemical screening test to identify secondary metabolites of Saputangan leaves extract (... more The Phytochemical screening test to identify secondary metabolites of Saputangan leaves extract (Maniltoa grandiflora (A.Gray) Scheff) showed positive results on phenolic and terpenoid compounds. The reagent used for phenolic screening was 5% FeCl3 and reagent for screening terpenoid was 1% CeSO4 in 10% H2SO4. Antibacterial test was carried out by agar diffusion method on extracts of DMSO Saputangan leaves. Phenolic compound obtained from extract of Saputangan leaves were 36.96 gram where the result was obtained after maceration, partitioning and evaporation processes. Antibacterial of phenolic compound was observed based on inhibitory zone diameters of phenolic compounds formed using paper discs with a diameter of 6 mm. The diameters of the inhibition zone against Escherichia coli bacteria are 8.1; 8.5 and 9.7 mm larger than the diameter of the inhibition zone in Staphylococcus aureus bacteria at 7.3; 7.8 and 8.5 mm. Then it can be stated that DMSO extracts of phenolic compound wit...

JURNAL PENGMAS KESTRA (JPK), 2021

Saputangan leaves contained terpenoids which appeared reddish brown rings when tested using Lieb... more Saputangan leaves contained terpenoids which appeared reddish brown rings when tested using Liebermann Burchard, Salkowski and cerric sulfate. Saputangan leaves were macerated, then partitioned to obtain total terpenoids using a separatory funnel while checking filtrate partition with cerric sulfate. Extracts dissolved with methanol were partitioned with n-Hexane and then partitioned between aquadest and ethyl acetate in a ratio of 1: 1 to obtain 50 g of total terpenoids. TLC analyses was performed on total terpenoids using n-hexane: acetone (80:20 v/v) solvent. The total terpenoids were proved that terpenoids have 11 terpenoids as red stain based on their Rf. Based on the results of tests conducted on participants involved in socialization, it was stated that around 98% of participants had understood terpenoid compounds.