Meiyu Geng

Person

Qingdao, CN

People

Patents Grantslast 30 patents

Information Patent Grant
Composition of mannuronic diacid
- Patent number 12,269,838
- Issue date Apr 8, 2025
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Substituted amino six-membered nitric heterocyclic ring compound an...
- Patent number 11,834,432
- Issue date Dec 5, 2023
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Ao Zhang
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Indolizine compounds, preparation method and use thereof
- Patent number 11,661,421
- Issue date May 30, 2023
- HAIHE BIOPHARMA CO., LTD.
- Xuxing Chen
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Fused ring pyrimidine amino compound and preparation method, pharma...
- Patent number 11,655,239
- Issue date May 23, 2023
- Shanghai Institute Of Material Medica, Chinese Academy of Sciences
- Bing Xiong
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Compound having ERK kinase inhibitory activity and use thereof
- Patent number 11,465,984
- Issue date Oct 11, 2022
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Lei Li
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Composition of alginic oligosaccharic diacids
- Patent number 11,464,794
- Issue date Oct 11, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Use of mannuronic diacid composition in treatment of Parkinson's di...
- Patent number 11,406,654
- Issue date Aug 9, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Use of mannuronic diacid composition in treatment of inflammation
- Patent number 11,406,659
- Issue date Aug 9, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Use of mannuronic diacid composition in treatment of diabetes
- Patent number 11,406,652
- Issue date Aug 9, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Use of mannuronic diacid composition in treatment of vascular dementia
- Patent number 11,406,651
- Issue date Aug 9, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Use of mannuronic diacid composition in treatment of pain
- Patent number 11,406,653
- Issue date Aug 9, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Composition of mannuronic diacid
- Patent number 11,384,111
- Issue date Jul 12, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICAL CO., LTD. SHANGHAI INSTITUTE OF MATERI...
- Meiyu Geng
- C08 - ORGANIC MACROMOLECULAR COMPOUNDS THEIR PREPARATION OR CHEMICAL WORKING-...
Information Patent Grant
Method of degrading polysaccharide using ozone
- Patent number 11,155,569
- Issue date Oct 26, 2021
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Zhongping Xiao
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
O-aminoheteroaryl alkynyl-containing compound, preparation method t...
- Patent number 10,988,456
- Issue date Apr 27, 2021
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Youhong Hu
- B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
Information Patent Grant
Pyrido five-element aromatic ring compound, preparation method ther...
- Patent number 10,968,215
- Issue date Apr 6, 2021
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Xuxing Chen
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Method for preparing oligomeric mannuronic diacid
- Patent number 10,927,137
- Issue date Feb 23, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Zhongping Xiao
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Pyrimido[5,4-B]indolizine or pyrimido[5,4-B]pyrrolizine compound, p...
- Patent number 10,829,491
- Issue date Nov 10, 2020
- SHANGHAI INSTITUTE OF MATERIA MEDICA, CHINESE ACAD
- Ao Zhang
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Aryl-2,2′-tandem bisthiazole compound and preparation method and us...
- Patent number 10,766,889
- Issue date Sep 8, 2020
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Fajun Nan
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Pyrido-azaheterecydic compound and preparation method and use thereof
- Patent number 10,710,996
- Issue date Jul 14, 2020
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Yaqiu Long
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Substituted quinolone derivatives, or pharmaceutically acceptable s...
- Patent number 10,683,278
- Issue date Jun 16, 2020
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Ke Ding
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Compound having mutant IDH inhibitory activity, preparation method...
- Patent number 10,682,352
- Issue date Jun 16, 2020
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Lei Jiang
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Indazole compounds as FGFR kinase inhibitor, preparation and use th...
- Patent number 10,562,900
- Issue date Feb 18, 2020
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Certain protein kinase inhibitors
- Patent number 10,328,060
- Issue date Jun 25, 2019
- Shanghai Fochon Pharmaceutical Co., LTD
- Xingdong Zhao
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Alginate oligosaccharides and the derivatives thereof as well as th...
- Patent number 10,213,456
- Issue date Feb 26, 2019
- Ocean University of China
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
2-aminopyrimidine compound and pharmaceutical composition and use t...
- Patent number 10,059,694
- Issue date Aug 28, 2018
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Ke Ding
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Five-member-heterocycle fused pyridine compounds, method of produci...
- Patent number 9,988,381
- Issue date Jun 5, 2018
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Jingkang Shen
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Certain protein kinase inhibitors
- Patent number 9,567,342
- Issue date Feb 14, 2017
- Shanghai Fochon Pharmaceutical Co., LTD
- Weibo Wang
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Algin oligosaccharides and the derivatives thereof as well as the m...
- Patent number 9,493,496
- Issue date Nov 15, 2016
- Ocean University of China
- Meiyu Geng
- C07 - ORGANIC CHEMISTRY
Information Patent Grant
Certain protein kinase inhibitors
- Patent number 9,206,166
- Issue date Dec 8, 2015
- Shanghai Institute of Materia Medica Academy of Sciences
- Weibo Wang
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Grant
Algin oligosaccharides and the derivatives thereof as well as the m...
- Patent number 8,835,403
- Issue date Sep 16, 2014
- Meiyu Geng
- C07 - ORGANIC CHEMISTRY

Patents Applicationslast 30 patents

Information Patent Application
S-CONFIGURATION-CONTAINING AMINO BENZAMIDE PYRIDAZINONE COMPOUND, P...
- Publication number 20240150300
- Publication date May 9, 2024
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Youhong HU
- C07 - ORGANIC CHEMISTRY
Information Patent Application
CSF1R KINASE INHIBITOR AND USE THEREOF
- Publication number 20230382871
- Publication date Nov 30, 2023
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Jian DING
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
USE OF CSF-1R KINASE INHIBITOR
- Publication number 20230285389
- Publication date Sep 14, 2023
- Shanghai Runshi Medical Technology Co., Ltd
- Ao ZHANG
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
FIVE-MEMBERED HETEROCYCLIC OXOCARBOXYLIC ACID COMPOUND AND MEDICAL...
- Publication number 20230032101
- Publication date Feb 2, 2023
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Wenhu DUAN
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
HETEROCYCLIC AMIDE COMPOUND, PHARMACEUTICALLY ACCEPTABLE SALT THERE...
- Publication number 20220389025
- Publication date Dec 8, 2022
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Wenhu DUAN
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
PHARMACEUTICAL COMPOSITIONS CONTAINING ALGINATE OLIGOSACCHARAIDE DI...
- Publication number 20220387477
- Publication date Dec 8, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Yingshen Jin
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
USE OF MANNURONIC ACID OLIGOSACCHARIDES OR COMPOSITION COMPRISING S...
- Publication number 20220362271
- Publication date Nov 17, 2022
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
COMPOSITION OF MANNURONIC DIACID
- Publication number 20220356202
- Publication date Nov 10, 2022
- GREEN VALLEY (SHANGHAI) PHARMACEUTICALS CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
COMPOUND HAVING AXL AND C-MET KINASE INHIBITORY ACTIVITY, PREPARATI...
- Publication number 20220324869
- Publication date Oct 13, 2022
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Wenhu DUAN
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
METHOD FOR TREATING ALZHEIMER'S DISEASE BY REGULATING AMINO ACID LEVEL
- Publication number 20220280589
- Publication date Sep 8, 2022
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
METHOD FOR IDENTIFYING CARBOHYDRATE DRUG-SENSITIVE PATIENT IN PATIE...
- Publication number 20220280541
- Publication date Sep 8, 2022
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- G01 - MEASURING TESTING
Information Patent Application
METHOD FOR TREATING ALZHEIMER'S DISEASE BY REGULATING INTESTINAL MI...
- Publication number 20220280578
- Publication date Sep 8, 2022
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
FUSED RING PYRIMIDINE AMINO COMPOUND AND PREPARATION METHOD, PHARMA...
- Publication number 20220274962
- Publication date Sep 1, 2022
- Shanghai Institute of Material Medica, Chinese Academy of Sciences
- Bing XIONG
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
METHOD FOR TREATING ALZHEIMER'S DISEASE BY INHIBITING UPTAKE OF AMI...
- Publication number 20220273598
- Publication date Sep 1, 2022
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
PYRIMIDO[5,4-B]PYRROLIZIN COMPOUND, OPTICAL ISOMER THEREOF, PREPARA...
- Publication number 20220204518
- Publication date Jun 30, 2022
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Ao ZHANG
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
FLUORINE-CONTAINING SUBSTITUTED BENZOTHIOPHENE COMPOUND, AND PHARMA...
- Publication number 20220089561
- Publication date Mar 24, 2022
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Ao ZHANG
- C07 - ORGANIC CHEMISTRY
Information Patent Application
USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF PAIN
- Publication number 20210361684
- Publication date Nov 25, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF DIABETES
- Publication number 20210322449
- Publication date Oct 21, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF INFLAMMATION
- Publication number 20210275570
- Publication date Sep 9, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF VASCULAR DEMENTIA
- Publication number 20210268006
- Publication date Sep 2, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF PARKINSON'S DI...
- Publication number 20210260089
- Publication date Aug 26, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
COMPOSITION OF ALGINIC OLIGOSACCHARIC DIACIDS
- Publication number 20210260085
- Publication date Aug 26, 2021
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
COMPOUND HAVING BET INHIBITORY ACTIVITY AND PREPARATION METHOD AND...
- Publication number 20210261539
- Publication date Aug 26, 2021
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Lin Xia
- C07 - ORGANIC CHEMISTRY
Information Patent Application
FUSED-CYCLIC PYRAZOLONE FORMAMIDE COMPOUND AND PREPARATION METHOD T...
- Publication number 20210221807
- Publication date Jul 22, 2021
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Hong LIU
- C07 - ORGANIC CHEMISTRY
Information Patent Application
QUINOLINE OR QUINAZOLINE COMPOUND AND APPLICATION THEREOF
- Publication number 20210078972
- Publication date Mar 18, 2021
- HAIHE BIOPHARMA CO., LTD.
- Ke DING
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
INDOLIZINE COMPOUNDS, PREPARATION METHOD AND USE THEREOF
- Publication number 20200399270
- Publication date Dec 24, 2020
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Xuxing Chen
- C07 - ORGANIC CHEMISTRY
Information Patent Application
COMPOSITION OF MANNURONIC DIACID
- Publication number 20200385417
- Publication date Dec 10, 2020
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Meiyu Geng
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
COMPOUND HAVING ERK KINASE INHIBITORY ACTIVITY AND USE THEREOF
- Publication number 20200247781
- Publication date Aug 6, 2020
- Shanghai Haihe Pharmaceutical Co., Ltd.
- Lei LI
- C07 - ORGANIC CHEMISTRY
Information Patent Application
SUBSTITUTED AMINO SIX-MEMBERED NITRIC HETEROCLIC RING COMPOUND AND...
- Publication number 20200172510
- Publication date Jun 4, 2020
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences
- Ao ZHANG
- A61 - MEDICAL OR VETERINARY SCIENCE HYGIENE
Information Patent Application
METHOD FOR PREPARING OLIGOMERIC MANNURONIC DIACID
- Publication number 20200055888
- Publication date Feb 20, 2020
- SHANGHAI GREEN VALLEY PHARMACEUTICAL CO., LTD.
- Zhongping Xiao
- C07 - ORGANIC CHEMISTRY

Person

Patents Grantslast 30 patents

Composition of mannuronic diacid

Substituted amino six-membered nitric heterocyclic ring compound an...

Indolizine compounds, preparation method and use thereof

Fused ring pyrimidine amino compound and preparation method, pharma...

Compound having ERK kinase inhibitory activity and use thereof

Composition of alginic oligosaccharic diacids

Use of mannuronic diacid composition in treatment of Parkinson's di...

Use of mannuronic diacid composition in treatment of inflammation

Use of mannuronic diacid composition in treatment of diabetes

Use of mannuronic diacid composition in treatment of vascular dementia

Use of mannuronic diacid composition in treatment of pain

Composition of mannuronic diacid

Method of degrading polysaccharide using ozone

O-aminoheteroaryl alkynyl-containing compound, preparation method t...

Pyrido five-element aromatic ring compound, preparation method ther...

Method for preparing oligomeric mannuronic diacid

Pyrimido[5,4-B]indolizine or pyrimido[5,4-B]pyrrolizine compound, p...

Aryl-2,2′-tandem bisthiazole compound and preparation method and us...

Pyrido-azaheterecydic compound and preparation method and use thereof

Substituted quinolone derivatives, or pharmaceutically acceptable s...

Compound having mutant IDH inhibitory activity, preparation method...

Indazole compounds as FGFR kinase inhibitor, preparation and use th...

Certain protein kinase inhibitors

Alginate oligosaccharides and the derivatives thereof as well as th...

2-aminopyrimidine compound and pharmaceutical composition and use t...

Five-member-heterocycle fused pyridine compounds, method of produci...

Certain protein kinase inhibitors

Algin oligosaccharides and the derivatives thereof as well as the m...

Certain protein kinase inhibitors

Algin oligosaccharides and the derivatives thereof as well as the m...

Patents Applicationslast 30 patents

S-CONFIGURATION-CONTAINING AMINO BENZAMIDE PYRIDAZINONE COMPOUND, P...

CSF1R KINASE INHIBITOR AND USE THEREOF

USE OF CSF-1R KINASE INHIBITOR

FIVE-MEMBERED HETEROCYCLIC OXOCARBOXYLIC ACID COMPOUND AND MEDICAL...

HETEROCYCLIC AMIDE COMPOUND, PHARMACEUTICALLY ACCEPTABLE SALT THERE...

PHARMACEUTICAL COMPOSITIONS CONTAINING ALGINATE OLIGOSACCHARAIDE DI...

USE OF MANNURONIC ACID OLIGOSACCHARIDES OR COMPOSITION COMPRISING S...

COMPOSITION OF MANNURONIC DIACID

COMPOUND HAVING AXL AND C-MET KINASE INHIBITORY ACTIVITY, PREPARATI...

METHOD FOR TREATING ALZHEIMER'S DISEASE BY REGULATING AMINO ACID LEVEL

METHOD FOR IDENTIFYING CARBOHYDRATE DRUG-SENSITIVE PATIENT IN PATIE...

METHOD FOR TREATING ALZHEIMER'S DISEASE BY REGULATING INTESTINAL MI...

FUSED RING PYRIMIDINE AMINO COMPOUND AND PREPARATION METHOD, PHARMA...

METHOD FOR TREATING ALZHEIMER'S DISEASE BY INHIBITING UPTAKE OF AMI...

PYRIMIDO[5,4-B]PYRROLIZIN COMPOUND, OPTICAL ISOMER THEREOF, PREPARA...

FLUORINE-CONTAINING SUBSTITUTED BENZOTHIOPHENE COMPOUND, AND PHARMA...

USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF PAIN

USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF DIABETES

USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF INFLAMMATION

USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF VASCULAR DEMENTIA

USE OF MANNURONIC DIACID COMPOSITION IN TREATMENT OF PARKINSON'S DI...

COMPOSITION OF ALGINIC OLIGOSACCHARIC DIACIDS

COMPOUND HAVING BET INHIBITORY ACTIVITY AND PREPARATION METHOD AND...

FUSED-CYCLIC PYRAZOLONE FORMAMIDE COMPOUND AND PREPARATION METHOD T...

QUINOLINE OR QUINAZOLINE COMPOUND AND APPLICATION THEREOF

INDOLIZINE COMPOUNDS, PREPARATION METHOD AND USE THEREOF

COMPOSITION OF MANNURONIC DIACID

COMPOUND HAVING ERK KINASE INHIBITORY ACTIVITY AND USE THEREOF

SUBSTITUTED AMINO SIX-MEMBERED NITRIC HETEROCLIC RING COMPOUND AND...

METHOD FOR PREPARING OLIGOMERIC MANNURONIC DIACID