Action mechanisms of herbicides and natural products
Antioxidative responses of plant cells to photooxidativestresses
Molecular mechanisms of herbicide resistance
Hiroshi MatsumotoYukari Sunohara
Mode of action of natural and synthetic
bioactive compounds in plants
CONT

24HAT

48HAT

Antioxidative responses in plants tophotooxidative stresses

72HAT

Onion roots treated with crude extractfrom Hapalosiphon sp.
Green：Viable cells
Red ：Dead cells

Detection of ROS generation in maize
root with fluorescent dye.
Left ：Control
Right：Herbicide treatment

Generation of ROS inphotosynthesis anddefensive measures inplants

Target identification of natural products
by forward chemical genetics
Naturally occurring small molecules are like a treasure box containing interesting leadcompounds with novel structures and useful biological activities. Some of them have agreat influence on the basic sciences and the pharmaceutical industry. We focus on
natural products possessing unique biological functions (for examples; pironetin,
terpendole E, brasilicardin A, and so on), and aim to discover the new biological aspect
by revealing their target molecules, binding sites, and inhibitory mechanisms.
OH O

Amphidinolide H (AmpH), isolated from Amphidinium sp., showed
potent cytotoxic activity, but its molecular target remained to bedetermined. We identified the molecular target of AmpH as actin
by several methods.

OHHOOH

Molecular target/binding site Identification

OOO

Observation of effects on living cells
0 nM

30 nM

Chem. Biol. 11, 1269-1277 (2004)

Flavor Research
Osamu Negishi
1. Biosynthesis of Vanillin

2. Enzymatic Deodorization with Foods
Raw Fruits,Vegetables & Mushrooms

Curing

Green Vanilla Beans

GarlicCured Vanilla Beans
(b)

(a)

(c)
CHO

HOHOIngestion
CH2OH

HOCOOHGlcO

HOGlc A&B

CHO

GlcO

OH

MeCHO

(All-S)

COOH

(d)'

H3C O

OH(e)'GlcO

HOCHO

COOGlcH3C O

RAll-SH

HO

H3C O

O

R:substituent

(e)

HOO

PPO
O2

R

CH2OH

COOGlc(d)

OH

All-S-S-All

(c)'

(b)'

(a)'

Ingestion

OH

H3C O

Figure 1. Proposed biosynthetic pathway for vanillin and related compounds
from phenylpropanoids, and formation of their glucosides and glucose esters ingreen vanilla beans (Vanilla planifolia).
(a) 4-coumaric acid; (b) 4-hydroxybenzaldehyde; (c) 4-hydroxybenzyl alcohol;(d) ferulic acid; (e) vanillin; and (a)’(b)’(c)’(d)’(e)’ show the respective glucose
esters or glucosides. Glc A&B are esters of tartaric acid and 2 molecules of (c)’.
During the curing process (e)’ is hydrolyzed by glucosidase in vanilla beans.

RAll-S-Me(AMS)

Figure 2. Formation of volatile sulfur compounds
deodorization.

(S-All)(All-S)

andenzymatic

Bad odors of the mouth and body after garlic ingestion can be decreasedby eating raw fruits, vegetables and mushrooms containing large amountsof polyphenolic compounds (PPs) and polyphenol oxidases (PPOs) .
The o-quinones produced from PPs by PPOs bind 2-propenethiols (AllSH)
and then the bad odors are removed from the reaction system.

Holotrichia parallela

Field bioassay of syntheticOHpheromone blend

A calling female ofPlodia interpunctella
OOOO
NH2Dinarmus basalis,

Zizeeria maha agria, a gravid female lays eggs

in response to chemicals in the host plant

Chemical ecology: Structure elucidations
and functional analyses of naturally
occurring chemicals that mediate
Apis cerana worker,
interactions between organisms and their indicating the nest
environment lead to the better
entrance by theunderstanding of nature and to thechemicals released
from 7th tergite
exploitation of the chemicals.

a parasitic wasp
recognizes host bychemicals left on thesurface of Azuki bean

Camponotus japonicus

Apis mellifera

Camponotus japonicus

Female alate ready to
Male alate inspecting thefly for her nuptial flightweather at the entrance

queen; Chemicalcommunications
betweenworkers in thecolony