EFSA Compendium of Botanicals

Draft - work in progress

Harungana madagascariensis Lam. ex Poir. // Haronga madagascariensis (Lam. ex Poir.) Choisy

Family:: Hypericaceae
Approval state:: Approved
Number of articles retrieved:: 181
Number of processed references:: 6

Compositions

#1: saponins in bark #2: alkaloids in bark #3: anthraquinone in bark #4: anthraquinone in bark #5: saponins in bark #6: tannins in bark #7: kengaquinone, kengathranol A-C, madagascin in bark #8: anthracene derivatives (harunganin, vismiaquinone) in bark #9: alkaloids in stembark #10: oxalates in stembark #11: cardiac glycosides in stembark #12: anthraquinones in stembark #13: saponins in stembark #14: Anthrones (harunganol A, harunganol B) in roots and stems

Endpoint Studies

#1: haematological changes: increase in white blood cell counts, reduced number of red blood cells and platelets #2: necrosis in hearth and lung tissue. #3: urinary tract constriction, necrosis in ovarian and testes #4: kenganthranol B - alpha-glucosidase inhibition #5: kenganthranol C - alpha-glucosidase inhibition #6: harunganin - alpha-glucosidase inhibition #7: physciol - alpha-glucosidase inhibition #8: harunganol B - alpha-glucosidase inhibition

Genotoxicity

Composition #1: Eze, Fredrick Nwude., Airouyuwa, Osamede Jennifer. Quantitative phytochemical evaluation of stem bark extracts of Harungana madagascariensis. british journal of pharmaceutical research, 2014, vol. 4, no. 17), 2068-207, p. 7 pp. .

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, hydroethanol
Substance:

Saponins (RF-00004333-PAR)
Analytical method - additional description:

unspecified
Result unit:

Percent (G138A)
Result expression:

Dry matter (B002A)
Result type:

Numerical Value (VAL)
Value (concentration, content):

0.38-0.59
Internal remarks:

saponins in bark

Composition #2: Eze, Fredrick Nwude., Airouyuwa, Osamede Jennifer. Quantitative phytochemical evaluation of stem bark extracts of Harungana madagascariensis. british journal of pharmaceutical research, 2014, vol. 4, no. 17), 2068-207, p. 7 pp. .

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, hydroethanol
Substance:

Alkaloids (RF-00004360-PAR)
Analytical method - additional description:

unspecified
Result unit:

Percent (G138A)
Result expression:

Dry matter (B002A)
Result type:

Numerical Value (VAL)
Value (concentration, content):

0.60-2.45
Internal remarks:

alkaloids in bark

Composition #3: Eze, Fredrick Nwude., Airouyuwa, Osamede Jennifer. Quantitative phytochemical evaluation of stem bark extracts of Harungana madagascariensis. british journal of pharmaceutical research, 2014, vol. 4, no. 17), 2068-207, p. 7 pp. .

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, hydroethanol
Substance:

Anthraquinone (RF-0475-001-PPP)
Analytical method - additional description:

unspecified
Result unit:

Percent (G138A)
Result expression:

Dry matter (B002A)
Result type:

Numerical Value (VAL)
Value (concentration, content):

0.42-0.54
Internal remarks:

anthraquinone in bark

Composition #4: Akah, P.A. Abortifacient activity of some Nigerian medicinal plants. phytotherapy research, 1994, vol. 8, no. 2, p. 106–108. DOI: 10.1002/ptr.2650080212. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

water
Substance:

Anthraquinone (RF-0475-001-PPP)
Analytical method code:

Phytochemical screening (F604A)
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

anthraquinone in bark

Composition #5: Akah, P.A. Abortifacient activity of some Nigerian medicinal plants. phytotherapy research, 1994, vol. 8, no. 2, p. 106–108. DOI: 10.1002/ptr.2650080212. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

water
Substance:

Saponins (RF-00004333-PAR)
Analytical method code:

Phytochemical screening (F604A)
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

saponins in bark

Composition #6: Akah, P.A. Abortifacient activity of some Nigerian medicinal plants. phytotherapy research, 1994, vol. 8, no. 2, p. 106–108. DOI: 10.1002/ptr.2650080212. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

water
Substance:

Tannins (RF-00004337-PAR)
Analytical method code:

Phytochemical screening (F604A)
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

tannins in bark

Composition #7: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

hexane
Substance:

anthraquinones (RF-00004343-PAR)
Additional substance description:

kengaquinone, kengathranol A-C, madagascin
Analytical method code:

Standard Chromatographic tests (paper- thin layer- and column chromatography) (F016A)
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

kengaquinone, kengathranol A-C, madagascin in bark

Composition #8: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

hexane
Substance:

anthracene derivatives (RF-00004342-PAR)
Additional substance description:

harunganin, vismiaquinone
Analytical method code:

Standard Chromatographic tests (paper- thin layer- and column chromatography) (F016A)
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

anthracene derivatives (harunganin, vismiaquinone) in bark

Composition #9: Antia, Bassey Sunday., Ita, Basil Nse., Udo, Uwemedimo Emmanuel. Nutrient Composition and In Vitro Antioxidant Properties of Harungana madagascariensis Stembark Extracts . journal of medicinal food, 2015, vol. 18, no. 5, p. 609–614. DOI: 10.1089/jmf.2014.0084. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

dichloromethane, methane
Substance:

Alkaloids (RF-00004360-PAR)
Analytical method code:

Phytochemical screening (F604A)
Analytical method - additional description:

Specific chemical test for quantitative assessment
Result unit:

Milligram/100 gram (G057A)
Result expression:

Dry matter (B002A)
Result type:

Numerical Value (VAL)
Value (concentration, content):

0.36-1.14
Internal remarks:

alkaloids in stembark

Composition #10: Antia, Bassey Sunday., Ita, Basil Nse., Udo, Uwemedimo Emmanuel. Nutrient Composition and In Vitro Antioxidant Properties of Harungana madagascariensis Stembark Extracts . journal of medicinal food, 2015, vol. 18, no. 5, p. 609–614. DOI: 10.1089/jmf.2014.0084. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, dichloromethane
Substance:

Oxalates (RF-00004308-PAR)
Additional substance description:

total
Analytical method - additional description:

Dye method
Result unit:

Milligram/100 gram (G057A)
Result expression:

Dry matter (B002A)
Result type:

Numerical Value (VAL)
Value (concentration, content):

3.64-4.63
Internal remarks:

oxalates in stembark

Composition #11: Antia, Bassey Sunday., Ita, Basil Nse., Udo, Uwemedimo Emmanuel. Nutrient Composition and In Vitro Antioxidant Properties of Harungana madagascariensis Stembark Extracts . journal of medicinal food, 2015, vol. 18, no. 5, p. 609–614. DOI: 10.1089/jmf.2014.0084. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, dichloromethane
Substance:

cardiac glycosides (RF-00010823-PAR)
Analytical method code:

Phytochemical screening (F604A)
Analytical method - additional description:

Liebermann’s test, Keller-Killiani’s test
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

cardiac glycosides in stembark

Composition #12: Antia, Bassey Sunday., Ita, Basil Nse., Udo, Uwemedimo Emmanuel. Nutrient Composition and In Vitro Antioxidant Properties of Harungana madagascariensis Stembark Extracts . journal of medicinal food, 2015, vol. 18, no. 5, p. 609–614. DOI: 10.1089/jmf.2014.0084. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, dichloromethane
Substance:

anthraquinones (RF-00004343-PAR)
Analytical method code:

Phytochemical screening (F604A)
Analytical method - additional description:

Benzene/ammonia solution
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

anthraquinones in stembark

Composition #13: Antia, Bassey Sunday., Ita, Basil Nse., Udo, Uwemedimo Emmanuel. Nutrient Composition and In Vitro Antioxidant Properties of Harungana madagascariensis Stembark Extracts . journal of medicinal food, 2015, vol. 18, no. 5, p. 609–614. DOI: 10.1089/jmf.2014.0084. [DOI link]

Language:

English (en)
Plant part:

Bark (as part-nature) (A066X)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

methanol, dichloromethane
Substance:

Saponins (RF-00004333-PAR)
Analytical method code:

Phytochemical screening (F604A)
Analytical method - additional description:

other chemical tests for quantitative assessment
Result unit:

Milligram/100 gram (G057A)
Result expression:

Dry matter (B002A)
Result type:

Numerical Value (VAL)
Value (concentration, content):

0.37-0.48
Internal remarks:

saponins in stembark

Composition #14: IINUMA, M., TOSA, H., ITO, T., TANAKA, T., AQIL, M. 2 PRENYLATED ANTHRONES IN HARUNGANA-MADAGASCARIENSIS. phytochemistry, 1995, vol. 40, no. 1, p. 267–270. DOI: 10.1016/0031-9422(95)00202-I. [DOI link]

Language:

English (en)
Plant part:

Live plants (as part-nature) (A0BA0)
Extraction/Preparation method:

Solvent extraction (A0BZR)
Additional extraction description:

benzene, acetone, methanol
Substance:

anthrones (RF-00010811-PAR)
Additional substance description:

harunganol A, harunganol B
Analytical method code:

Nuclear Magnetic Resonance (NMR) (F061A)
Analytical method - additional description:

NMR, IR
Yes/No Qualitative:

Positive/Present (POS)
Result type:

Qualitative Value (Binary) (BIN)
Internal remarks:

Anthrones (harunganol A, harunganol B) in roots and stems

Endpoint study #1: Etame, R.M.E., Mouokeu, R.S., Ngane, R.A.N., Assam, J.P.A., Masoohe, A.M., Tientcheu, R., Hopogap, M.L., Etoa, F.X. Acute and sub-acute toxicity of Harungana madagascariensis LAM (Hypericaceae) stem bark methanol extract. journal of applied pharmaceutical science, 2017, vol. 7, no. 3, p. 160–167. DOI: 10.7324/JAPS.2017.70326. [DOI link]

Study relevance:

Human health
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

methanol
Type of toxicological test:

short-term toxicity (CHD017TT)
Limit test:

Not applicable
Guideline:

OECD GUIDELINE 407 (REPEATED DOSE 28-DAY ORAL TOXICITY IN RODENTS) (OECD1255PL)
Tested organism:

Rat (as animal) (A0CNV)
Strain of test organism:

Wistar (CHD013ST)
Sex:

Male/Female
Route of exposure:

ORAL: GAVAGE (OECD2231PL)
Exposure duration:

28.0
Unit of exposure duration:

Day (G134A)
Number of organisms dosed:

80
Control groups used:

yes, concurrent vehicle
Endpoint measured:

Dose level (CHD014EP)
Concentration unit:

Milligrams per kilogram body weight (G225A)
Effect concentration:

200
Critical effect:

SYSTEMIC (TOX01A)
Target tissue:

Cardiovascular / Haematological (TT001A)
Effect description:

increase in white blood cell counts, reduced number of red blood cells and platelets
Effect or parameter linked to the endpoint:

haematology (CHD023BE)
Internal remarks:

haematological changes: increase in white blood cell counts, reduced number of red blood cells and platelets

Endpoint study #2: Etame, R.M.E., Mouokeu, R.S., Ngane, R.A.N., Assam, J.P.A., Masoohe, A.M., Tientcheu, R., Hopogap, M.L., Etoa, F.X. Acute and sub-acute toxicity of Harungana madagascariensis LAM (Hypericaceae) stem bark methanol extract. journal of applied pharmaceutical science, 2017, vol. 7, no. 3, p. 160–167. DOI: 10.7324/JAPS.2017.70326. [DOI link]

Study relevance:

Human health
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

methanol
Type of toxicological test:

short-term toxicity (CHD017TT)
Limit test:

Not applicable
Guideline:

OECD GUIDELINE 407 (REPEATED DOSE 28-DAY ORAL TOXICITY IN RODENTS) (OECD1255PL)
Tested organism:

Rat (as animal) (A0CNV)
Strain of test organism:

Wistar (CHD013ST)
Sex:

Male/Female
Route of exposure:

ORAL: GAVAGE (OECD2231PL)
Exposure duration:

28.0
Unit of exposure duration:

Day (G134A)
Number of organisms dosed:

80
Control groups used:

yes, concurrent vehicle
Endpoint measured:

Dose level (CHD014EP)
Concentration unit:

Milligrams per kilogram body weight (G225A)
Effect concentration:

200
Critical effect:

PULMONARY AND CARDIAC (TOX08A)
Target tissue:

cardiovascular / haematological: Blood Coagulation (TT010A)
Effect description:

necrosis in hearth muscle and lung
Effect or parameter linked to the endpoint:

histopathology non neoplastic (CHD025BE)
Internal remarks:

necrosis in hearth and lung tissue.

Endpoint study #3: Etame, R.M.E., Mouokeu, R.S., Ngane, R.A.N., Assam, J.P.A., Masoohe, A.M., Tientcheu, R., Hopogap, M.L., Etoa, F.X. Acute and sub-acute toxicity of Harungana madagascariensis LAM (Hypericaceae) stem bark methanol extract. journal of applied pharmaceutical science, 2017, vol. 7, no. 3, p. 160–167. DOI: 10.7324/JAPS.2017.70326. [DOI link]

Study relevance:

Human health
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

methanol
Type of toxicological test:

short-term toxicity (CHD017TT)
Limit test:

Not applicable
Guideline:

OECD GUIDELINE 407 (REPEATED DOSE 28-DAY ORAL TOXICITY IN RODENTS) (OECD1255PL)
Tested organism:

Rat (as animal) (A0CNV)
Strain of test organism:

Wistar (CHD013ST)
Sex:

Male/Female
Route of exposure:

ORAL: GAVAGE (OECD2231PL)
Exposure duration:

28.0
Unit of exposure duration:

Day (G134A)
Number of organisms dosed:

80
Control groups used:

yes, concurrent vehicle
Endpoint measured:

Dose level (CHD014EP)
Concentration unit:

Milligrams per kilogram body weight (G225A)
Effect concentration:

200
Critical effect:

SYSTEMIC (TOX01A)
Target tissue:

Urogenital (TT006A)
Effect description:

ovarian and testes necrosis, urinary tract constriction
Effect or parameter linked to the endpoint:

histopathology non neoplastic (CHD025BE)
Internal remarks:

urinary tract constriction, necrosis in ovarian and testes

Endpoint study #4: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Study relevance:

Human health
Substance:

anthraquinones (RF-00004343-PAR)
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

kenganthranol B, solvent - methanol 100%
Type of toxicological test:

in vitro (CHD061TT)
Tested organism:

Saccharomyces cerevisiae (as organism) (A0CPH)
Control groups used:

no data
Endpoint measured:

Enzyme inhibition (CHD067EP)
Concentration unit:

Millimole (G115A)
Effect concentration:

0.0063
Critical effect:

Digestive (TOX18A)
Target tissue:

Digestive (TT002A)
Effect description:

alpha-glucosidase inhibition
Effect or parameter linked to the endpoint:

enzyme inhibition (CHD032BE)
Internal remarks:

kenganthranol B - alpha-glucosidase inhibition

Endpoint study #5: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Study relevance:

Human health
Substance:

anthraquinones (RF-00004343-PAR)
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

kenganthranol C, solvent - methanol 100%
Type of toxicological test:

in vitro (CHD061TT)
Tested organism:

Saccharomyces cerevisiae (as organism) (A0CPH)
Control groups used:

no data
Endpoint measured:

Enzyme inhibition (CHD067EP)
Concentration unit:

Millimole (G115A)
Effect concentration:

0.0219
Critical effect:

Digestive (TOX18A)
Target tissue:

Digestive (TT002A)
Effect description:

alpha-glucosidase inhibition
Effect or parameter linked to the endpoint:

enzyme inhibition (CHD032BE)
Internal remarks:

kenganthranol C - alpha-glucosidase inhibition

Endpoint study #6: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Study relevance:

Human health
Substance:

Quinones (RF-00010832-PAR)
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

harunganin, solvent - methanol 100%
Type of toxicological test:

in vitro (CHD061TT)
Tested organism:

Saccharomyces cerevisiae (as organism) (A0CPH)
Control groups used:

no data
Endpoint measured:

Enzyme inhibition (CHD067EP)
Concentration unit:

Millimole (G115A)
Effect concentration:

0.006
Critical effect:

Digestive (TOX18A)
Target tissue:

Digestive (TT002A)
Effect description:

alpha-glucosidase inhibition
Effect or parameter linked to the endpoint:

enzyme inhibition (CHD032BE)
Internal remarks:

harunganin - alpha-glucosidase inhibition

Endpoint study #7: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Study relevance:

Human health
Substance:

physcion (RF-00003993-PAR)
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

methanol 100%
Type of toxicological test:

in vitro (CHD061TT)
Tested organism:

Saccharomyces cerevisiae (as organism) (A0CPH)
Control groups used:

no data
Endpoint measured:

Enzyme inhibition (CHD067EP)
Concentration unit:

Millimole (G115A)
Effect concentration:

0.1923
Critical effect:

Digestive (TOX18A)
Target tissue:

Digestive (TT002A)
Effect description:

alpha-glucosidase inhibition
Effect or parameter linked to the endpoint:

enzyme inhibition (CHD032BE)
Internal remarks:

physciol - alpha-glucosidase inhibition

Endpoint study #8: Kouam, SF., Khan, SN., Krohn, K., Ngadjui, BT., Kapche, DGWF., Yapna, DB., Zareem, S., Moustafa, AMY., Choudhary, MI. alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis . journal of natural products, 2006, vol. 69, no. 2, p. 229–233. DOI: 10.1021/np050407n. [DOI link]

Study relevance:

Human health
Substance:

anthraquinones (RF-00004343-PAR)
Plant part:

Bark (as part-nature) (A066X)
Preparation/Extraction method:

Solvent extraction (A0BZR)
Additional plant/substance description:

harunganol B, solvent - methanol 100%
Type of toxicological test:

in vitro (CHD061TT)
Tested organism:

Saccharomyces cerevisiae (as organism) (A0CPH)
Control groups used:

no data
Endpoint measured:

Enzyme inhibition (CHD067EP)
Concentration unit:

Millimole (G115A)
Effect concentration:

0.012
Critical effect:

Digestive (TOX18A)
Target tissue:

Digestive (TT002A)
Effect description:

alpha-glucosidase inhibition
Effect or parameter linked to the endpoint:

enzyme inhibition (CHD032BE)
Internal remarks:

harunganol B - alpha-glucosidase inhibition